Why high resolution digital systems are required, and why the humble CD is far from being transparent...
François Yves Le Gal
Fellow, and Michael W. Pflaumer:
"As the compact disc (CD) has become a widely used medium for
distribution of high fidelity audio, it has become apparent that its
sound quality is not as high as original expectations, which were based
primarily on conventional distortion and frequency response
measurements. This view has been expressed both by those involved in the
production of CD's and by fidelity conscious consumers.
Dissatisfaction with the fidelity of CD digital recordings when compared
to analog master tapes of the same recording sessions prompted the
authors to investigate the factors responsible for the loss of fidelity
and to devise approaches for improving the situation.
../...
The peak dynamic range requirement for professional recording has been
shown to approach 130 dB [2]. Even conservative estimates produce
numbers greater than 120 dB [3]. While the capabilities of an average
home playback system cannot cover this range because the average home
speaker system cannot reach the necessary peak sound pressure level
(SPL), there will always be some systems which can. In addition, edit
situations and listeners who change gain during a program pose added
dynamic requirements. Therefore, these numbers remain a valid target.
../...
Research [2] has shown that distortion products other than low order
harmonics must be kept at least 120 dB below peak levels in the presence
of complex signals in order to achieve a satisfactory level of accuracy
in a critical listening environment. Since interactions with different
listening systems may bring out different problems, this level of
performance is required to be safe for all cases.
../...
Our current research indicates that infrequent distortion products with
peak levels in the -120 dB full scale (dBFS) range are potentially
audible [4]".
"Compatible Resolution Enhancement in Digital Audio Systems", [1]
Johnson and Pflaumer very clearly establish that the dynamic range of CD
is vastly insufficient, building on research conducted by Louis D.
Fielder, an AES Fellow and a former AES president [1 and 3], who had
established years earlier that the "reproduction of music at natural
sound levels requires very high peak sound levels of up to 129dB spl",
with some instruments, such as percussions or brass sections, being
"capable of producing over 40 acoustic watts".
How loud are 40 acoustic watts? Well, around 128 dB spl...
Supposing a typical 0,5 % efficient pair of speakers - for 89,14 dB/m
when driven by 1 W, you would need 4 Kw of amplifier power in order to
reach 128+ dB peaks...
Quoting John Atkinson in Stereophile [6]: "Want to talk power? A typical
moving-coil loudspeaker is around 1% efficient. When you're pinning back
your ears with a 100Wpc amp running flat out, the speakers are putting
out just two acoustic watts into your listening room. By contrast, a
single trombone in full song pumps out as much as 35 acoustic watts!
You'd need a 1750Wpc amp to energize the room to the same extent,
assuming your speakers didn't go into terminal meltdown.
I experienced this raw power firsthand when I recorded Stereophile's
Rendezvous jazz CD in 1998. To get adequate separation from the adjacent
instruments, I had close-miked Art Baron's 'bone with a B&K omni about
12" in front of the instrument's bell. I started out with a moderate
amount of gain on the Nagra-D's preamp, but once Art started rocking out
on his solos, the mike was putting out volts rather than the expected
millivolts. I ended up having to use both 3dB attenuation on the
recorder's level pot and a 10dB external pad to avoid clipping the A/D
converter. Even then, I had to get Art to back away from the mike on
occasion."
John Tomarakos states [7] that a "musical source material recorded with
microphones at a typical listening position can require a dynamic range
of up to 118 dB from an audio processing system to reproduce it without
the latter introducing audible noise. This requirement can be increased
further with the use of microphones sited closer to the source" [5], so
we've got 118 dB even before taking into account headroom and footroom,
for a total requirement of around 130 dB!
The human auditory system is perfectly able to cope with such dynamics:
"Recent advancements within the past decade in human hearing indicate
the sensitivity of the human ear is such that the dynamic range between
the quietest sound detectable and the maximum sound which can be
experienced without pain is approximately 120dB".
The author then introduces a bandwith requirement: " Further studies
suggest there is critically important audio information at frequencies
up to 40 kHz and possibly 80 kHz".
We'll discuss it later on.
Tomarakos et al. confirm this point in the JAES [9]: "When the compact
disc was launched in the early 1980s, the digital format of 16-bit words
sampled at 44.1 kHz, was chosen for a mixture of technical and
commercial reasons. The choice was limited by the quality of available
analog-to-digital converters, by the quality and cost of other digital
components, and by the density at which digital data could be stored on
the medium itself. It was thought that the format would be sufficient to
record audio signals with all the fidelity required for the full range
of human hearing. However, research since the entrance of CD technology
has shown that this format is imperfect in some respects.
New research conducted within the last decade indicates that the
sensitivity of the human ear is such that the dynamic range between the
quietest sound detectable and the maximum sound which can be experienced
without pain is approximately 120dB. Therefore, 16-bit CD-quality audio
is no longer thought to be the highest-quality audio that can be stored
and played back. Also, many audiophiles claimed that CD-quality audio
lacked a certain warmth that a vinyl groove offered. This may have been
due to a combination of the dynamic range limitation of 16-bits as well
as the chosen sample rate of 44.1 kHz. The 16-bit words used for CD
allow a maximum dynamic range of 96 dB although with the use of dither
this is reduced to about 93 dB. Digital conversion technology has now
advanced to the stage where recordings with a dynamic range of 120dB or
greater may be made, but compact disc is unable to accurately carry
them.
Recent technological developments and improved knowledge of human
hearing have created a demand for greater word lengths and faster
sampling rates in the professional and consumer audio sectors. It has
long been assumed that the human ear was capable of hearing sounds up to
a frequency of about 20 kHz and was completely insensitive to
frequencies above this value. This assumption was a major factor in the
selection of a 44.1 kHz sampling rate. New research has suggested that
many people can distinguish the quality of audio at frequencies of up to
25 kHz, and that humans are also sensitive to a degree to frequencies
above even this value. This research is mainly empirical, but would mean
that a substantially higher sampling frequency is necessary. D. E.
Blackmer [7] has suggested that in order to fully meet the requirements
of human auditory perception, a sound systems must be designed to cover
the frequency range to up to 40 kHz (and possibly up to 80 kHz) with
over 120 dB dynamic range to handle transient peaks. This is beyond the
requirements of many of today's digital audio systems. As a result, 18,
20 and even 24 bit analog-to-digital converters are now widely available
which are capable of exceeding the 96dB dynamic range available using 16
bits".
Blackmer et al. build on various Japanese research, beginning in 1991
with "High-Frequency Sound above the Audible Range Affects Brain
Electric Activity and Sound Perception" [10] and, for the more
specifically audio-oriented part, with "Sound Quality Evaluation of 96
kHz Sampling Digital Audio" [11], using double blind tests which very
clearly establish that high resolution PCM is objectively and
subjectively *better*.
HR PCM is also preferable in other aspects, as demonstrated in "Does
High Sampling Frequency Improve Perceptual Time-Axis Resolution of
Digital Audio Signal?"
"Reference signals and test signals were presented alternately to the
subjects. The subjects were asked whether the test signal is equal to
the reference signal or not by hearing. The subjects were 11 males, age
22 to 24, having normal hearing. Purpose of this experiment is to
confirm the following hypothesis. Since the waveform of a pulse signal
reproduced by the 40-kHz bandwidth system is more similar to the
original signal than by the 20-kHz bandwidth system. We can assume that
the subjects would be able to identify the interval of the test signal
more easily and more correctly using the 40-kHz system thab using the
20-kHz system. When the interval of the test signal is short,
identification becomes easier, but when it becomes long, identification
becomes rather difficult".
High resolution formats can be distinguished from basic PCM *and* offer
subjective benefits even for people unable to hear or perceive
ultrasonics.
This point has been confirmed by numerous other papers, such as
"Anti-alias and anti-image filtering: The benefits of 96kHz sampling
rate formats for those who cannot hear above 20kHz" [13]
"Filters designed for the higher sampling frequency of 96kHz are used to
show how all these distortion mechanisms can be reduced by filters of
similar computational requirements but with a more relaxed transition
region. This results in either reduced ripple (and hence pre-echo)
amplitude or in a lower time displacement for the echo.
In both cases the effect is likely to be a reduction in the audibility
of the echo. A direct effect of the higher sampling rate is that for an
identical filter design the time displacements will scale inversely with
sample rate. Hence an improvement can be made just from raising the
sample rate - even for those who cannot hear above 20kHz."
In conclusion, it has been very clearly established that CD is not
sufficient for the reproduction of music, and that high resolution
systems - such as HRPCM or DSD - are required.
[1] "Compatible Resolution Enhancement in Digital Audio Systems", Keith
O. Johnson and Michael W. Pflaumer, Preprint 4392, AES 101, November
1996
[2] "Dynamic-Range Requirement for Subjectively Noise-Free Reproduction
of Music", Journal of the Audio Engineering Society, Vol 30 7/8,
July/August 1982; summarized in "Human Auditory Capabilities and Their
Consequences in Digital-Audio Converter Design," AES 7th International
Conference, Toronto, Paper 4A, May 1989
[3] "The Spectral Amplitude Distribution of Selected Compact Discs," R.
A Greiner and Jeff Eggers, Jouranl of the Audio Engineering Society, Vol
37 4, April 1989
[4] "Dynamic Range in Digital Audio", Louis D. Fielder, Journal of the
Audio Engineering Society, Vol. 43 5, May 1995
[5] "High Dynamic Range Audio Applications for Digital Signal
Processing", Julian Dunn, Preprint 3434, AES 93, October 1992.
[6] "Jump'n'Jive & the Absolute Sound", John Atkinson, Stereophile,
XXV/7, July 2002
[7] "The World Beyond 20 kHz", DE Blackmer, Studio Sound, Jan 1999
[8] "The Relationship of Data Word Size to Dynamic Range and Signal
Quality in Digital Audio Processing Applications", John Tomarakos,
Analog Devices, Inc., Norwood, MA
[9] "32-bit SIMD SHARC Architecture for Digital Audio Signal Processing
Applications", J. Tomarakos and C. Duggan, Journal of the Audio
Engineering Society, Vol 48 3, March 2000
[10] "High-Frequency Sound above the Audible Range Affects Brain
Electric Activity and Sound Perception", T. Oohashi, E. Nishina, N.
Kawai, Y. Fuwamoto and H. Imai, Preprint 3207, AES 91, October 1991
[11] "Sound Quality Evaluation of 96 kHz Sampling Digital Audio", S.
Yoshikawa, S. Noge, M. Ohsu, S. Toyama, H. Yanagawa and T.
Yamamoto, Preprint 4112, AES 99, October 1995
[12] "Does High Sampling Frequency Improve Perceptual Time-Axis
Resolution of Digital Audio Signal?", S. Yoshikawa, S. Noge, T.
Yamamoto, K. Saito, Preprint 4562, AES 103, September 1997
[13] "Anti-alias and anti-image filtering: The benefits of 96kHz
sampling rate formats for those who cannot hear above 20kHz", Julian
Dunn, Preprint 4734, AES 104, 1998
Nota: the references in the various quotes have been edited in order to
avoid any confusion and only refer to those supplied in this post.
François Yves Le Gal
Enhancement in Digital Audio Systems", [1] by Keith O. Johnson, an AES
Johnson and Pflaumer very clearly establish that the dynamic range of CD
is vastly insufficient, building on research conducted by Louis D.
Fielder, an AES Fellow and a former AES president [2 and 4], who had
Richard D Pierce
fact here.
In article <atdgmj$uaj$1...@bourbaki.localdomain>,
François Yves Le Gal <fle...@aingeal.com> wrote:
>Let me begin by quoting an AES preprint by Keith O. Johnson, an AES
>Fellow, and Michael W. Pflaumer:
Please note that AES convention preprints are not subject to the
same level of scrutiny as published articles. Indeed, they are
subject to almost NO review whatsoever. Therefore, there is no
independent verification of the claims stated in such an
article, no peer review, nothing. PLease note that I state this
from a position of some experience, having been, in fact, an AES
convention papers review comittee member. Us reviewers have ONLY
the precise of the article available for reqview.
>How loud are 40 acoustic watts? Well, around 128 dB spl...
At what distance? At 1 meter, yes, 40 acoustic watts produces
a sound pressure level of 128 dB SPL assuming omnidirectional
radiation. Please enumerate the listening venues which result in
sitting 1 meter away from a sound source radiating 40 acoustic
watts.
>Supposing a typical 0,5 % efficient pair of speakers - for 89,14 dB/m
>when driven by 1 W, you would need 4 Kw of amplifier power in order to
>reach 128+ dB peaks...
>
>Quoting John Atkinson in Stereophile [6]: "Want to talk power? A typical
>moving-coil loudspeaker is around 1% efficient. When you're pinning back
>your ears with a 100Wpc amp running flat out, the speakers are putting
>out just two acoustic watts into your listening room. By contrast, a
>single trombone in full song pumps out as much as 35 acoustic watts!
>You'd need a 1750Wpc amp to energize the room to the same extent,
>assuming your speakers didn't go into terminal meltdown.
This is an absurd conclusion. First, assume the trumpet is
producing 35 acoustic watts (there are reasons to question the
wisdom of this claim). The claim here is that in our listening
room, we need the speakers to produce the same 35 acoustic watts
the trumpet is reproducing. This is absurd.
If what you are claiming is that we need to to reproduce the
same SPL in our listeing room from our listening position as we
would have experienced in the original listening venue with it
MUCH larger vaolume and MUCH larger listening distances, that
ODES NOT require 35 acoustic watts. TO claim so absurdly ignore
even the most basic physics of the situation.
>I experienced this raw power firsthand when I recorded Stereophile's
>Rendezvous jazz CD in 1998. To get adequate separation from the adjacent
>instruments, I had close-miked Art Baron's 'bone with a B&K omni about
>12" in front of the instrument's bell. I started out with a moderate
>amount of gain on the Nagra-D's preamp, but once Art started rocking out
>on his solos, the mike was putting out volts rather than the expected
>millivolts. I ended up having to use both 3dB attenuation on the
>recorder's level pot and a 10dB external pad to avoid clipping the A/D
>converter. Even then, I had to get Art to back away from the mike on
>occasion."
CLose micing is one thing, yes the SPL's are large when you are
1' away from the bell of a trumpet. But that does NOT in any
rational or plausible fashioon duplicate the SPL's that one
would encounter from an actual listening position. Let's explore
this.
Assume Mr. Atkinson was encountering SPL's of 128 dB. That's
REALLY loud. DOes that mean the trumpet was producing 35
acoustic watts? Absolutely not. If the mike distance was 1 foot,
as an example, the power per unit area would be 10 times that
encountered at 1 meter, so the 1 meter SPL is now only 118 dB.
That's equivalent to only 10 acoustic watts. The radiation
pattern of the horn is restricted, which means that the total
sound power is NOT uniformly distrubted omnidirectionally. As an
example, consider it being directed over a hemisphere (over the
range of the truimpets harmonic structuire, it's actually
significantly less). That reduces the power output by a factor
of 2. Now we are down to 5 acoustic watts to produce 128 dB at 1
foot. Once can also consider proximity effects, which reduces
the effected radiated power further for the same SPL
Now, I would suggest, sir, you engage in a little science
investigation. Please calculate the required air pressure and
flow volume needed to produce 70 watts (assume the trumpet
itself has an instrinsic conversion efficiency itself of 50%, a
high esitimate). Answer the following question: can a human
repiratory system produce that air pressure and flow volume
simultaneously? (hint: the human respiratory system is limited
in its ability to produce pressure to something in the range of
about 10-15" W.C.).
Whether or not the dynamic range requirements quoted are
required, these two points leap out as examples of either bad
science, or attempts at crdibility by loose association. The
dynamic range requirements may well be needed, they may not. But
this is a lousy way to attempt to prove it.
--
| Dick Pierce |
| Professional Audio Development |
| 1-781/826-4953 Voice and FAX |
| DPi...@world.std.com |
François Yves Le Gal
wrote:
>There are several opinions and incorrect assumptions stated as
>fact here.
Oh. You say "several". We'll get back to this later.
>Please note that AES convention preprints are not subject to the
>same level of scrutiny as published articles.
I guess that everyone here is well aware of this fact. Only articles are
fully peer-reviewed.
>At what distance? At 1 meter, yes, 40 acoustic watts produces
>a sound pressure level of 128 dB SPL assuming omnidirectional
>radiation.
That's what I wrote, Mr. Pierce, thank you for paraphrasing my post and
adding a totally irrelevant pseudo demonstration.
>This is an absurd conclusion.
Which conclusion?
>Whether or not the dynamic range requirements quoted are
>required, these two points leap out as examples of either bad
>science, or attempts at crdibility by loose association
What are the two points you criticize?
I can find one - John Atkinson's description of a recording session. His
figures are very close to those supplied by Louis Fielder, who has
demonstrated earlier that the "reproduction of music at natural sound
levels requires very high peak sound levels of up to 129dB spl", with
some instruments, such as percussions or brass sections, being "capable
of producing over 40 acoustic watts".
The references come from the AES Journal, not from preprints,
respectively [2] "Dynamic-Range Requirement for Subjectively Noise-Free
Reproduction of Music", Journal of the Audio Engineering Society, Vol 30
7/8, July/August 1982 and [4] "Dynamic Range in Digital Audio", Louis D.
Fielder, Journal of the Audio Engineering Society, Vol. 43 5, May 1995
The AES Journal is fully peer reviewed, Mr. Pierce. So your initial as
well as subsequent objections don't hold.
>The
>dynamic range requirements may well be needed, they may not. But
>this is a lousy way to attempt to prove it.
Well, Mr. Pierce, you haven't addressed the rest of my post, only
dealing with one reference out of thirteen. You stated in your opening
remarks that "[t]here [were] several opinions and incorrect assumptions
stated as fact here".
You've only addressed *one* so far, and your arguments have been fully
refuted. So let me ask, again, what are the other points? If I may say
so, your post is a very lousy way to attempt disproving mine.
Anyway, as all supplied references demonstrate, CD is only able to
present a reasonable fac-simile of the actual musical event. High
resolution digital systems are required in order to approach a higher
fidelity to the actual musical event.
Arny Krueger
news:atdgmj$uaj$1...@bourbaki.localdomain
Apparently it has become stylish on RAHE to play "Name That Paper".
The way this game works is that a profusion of quotes from a
scientific paper are quoted without actually naming the paper.
The paper in question appears to be:
Compatible Resolution Enhancement in Digital Audio Systems
Author(s): Johnson, Keith O.; Pfaumer, Michael W.
Publication: Preprint 4392; AES
Convention 101; November 1996
Abstract: A conjugate record and playback system is described, which
enhances the resolution and sonic performance of digital audio
recording based on linear pulse-code modulation, while remaining
compatible with standard linear playback. Using additional
information encoded entirely in the program material, it addresses
both the amplitude resolution and sampling-rate limitations of the
current commercial recording standards.
The technology that this paper attempts to justify is none other than
the erstwhile "HDCD". As many of us recall, HDCD had at least 5
years to prove itself in the audio marketplace and failed to garner
much interest or excitement among consumers. The technology was
liquidated by its developers and it is now relegated to the role of a
minor feature of the audio subsystem of Microsoft's Windows Media.
BTW I don't think that there is any question that HDCD delivered on
its technical claims. Arguably, its benefits are easier to justify
technically and psychoacoustically, than either HDCD or SACD. HDCD
was also a more economical system to implement and was
media-compatible with existing players.
In the identical same timeframe, a vastly sonically and measurably
inferior technology with DBT-proven degraded sonics, namely "MP3"
gained tens of millions of consumer supporters.
It seems like there is a lesson to be learned here, but the
implementers of SACD and DVD-A seems to have missed it.
HDCD was like a dry run, test-market, market-survey, consumer opinion
panel test for SACD and/or DVD-A. Too bad that additional millions or
billions will be spent despite our knowledge of the outcome of the
tests.
BEAR
> There are several opinions and incorrect assumptions stated as
> fact here.
>
> In article <atdgmj$uaj$1...@bourbaki.localdomain>,
> Fran=E7ois Yves Le Gal <fle...@aingeal.com> wrote:
>
<snip>
>
>
> >How loud are 40 acoustic watts? Well, around 128 dB spl...
>
> At what distance? At 1 meter, yes, 40 acoustic watts produces
> a sound pressure level of 128 dB SPL assuming omnidirectional
> radiation. Please enumerate the listening venues which result in
> sitting 1 meter away from a sound source radiating 40 acoustic
> watts.
The most obvious one is the guy sitting in the band the row in front of
the row of 'bones...
Now, the people *dancing* in front of the *row* of 'bones, trumpets
and sax's... or in the front row in the club...
Guess it never happens...
_-_-bear
>
>
>
<snip>
> --
> | Dick Pierce |
> | Professional Audio Development |
> | 1-781/826-4953 Voice and FAX |
> | DPi...@world.std.com |
--
_-_-bearlabs
http://www.bearlabsUSA.com
- Silver Lightning Interconnects & Custom Mods -
normanstrong
> moving-coil loudspeaker is around 1% efficient. When you're pinning back
> your ears with a 100Wpc amp running flat out, the speakers are putting
> out just two acoustic watts into your listening room. By contrast, a
> single trombone in full song pumps out as much as 35 acoustic watts!
> You'd need a 1750Wpc amp to energize the room to the same extent,
> assuming your speakers didn't go into terminal meltdown.
Has anyone checked out these numbers? I question the ability of human lungs
to put out 35 watts.
Norm Strong
François Yves Le Gal
>Apparently it has become stylish on RAHE to play "Name That Paper".
>The way this game works is that a profusion of quotes from a
>scientific paper are quoted without actually naming the paper.
Mr. Krueger, if you had read and understoood my post, you would have
noticed that all references were duly noted and detailed.
The Johnson and Pflaumer preprint was referred as such, including it's
complete title in the text: "AES preprint, "Compatible Resolution
Enhancement in Digital Audio Systems", [1] by Keith O. Johnson, an AES
Fellow, and Michael W. Pflaumer".
The [1] points to the reference list after my post, where, if you had
read all of the post, you would have found "[1] "Compatible Resolution
Enhancement in Digital Audio Systems", Keith O. Johnson and Michael W.
Pflaumer, Preprint 4392, AES 101, November 1996", a full reference to
the quoted preprint.
Please try to read and understand the posts you try to address next
time. Oh, and please try to read your posts before hitting <SEND>. For
instance, what do you mean by: "BTW I don't think that there is any
question that HDCD delivered on its technical claims. Arguably, its
benefits are easier to justify technically and psychoacoustically, than
either HDCD or SACD"?
Hmm. HDCD delivered and is easier to justify than HDCD... Quite
interesting.
Arny Krueger
news:atfq6...@enews4.newsguy.com
> I can find one - John Atkinson's description of a recording
> session. His figures are very close to those supplied by Louis
> Fielder, who has demonstrated earlier that the "reproduction of
> music at natural sound levels requires very high peak sound
> levels of up to 129dB SPL", with some instruments, such as
> percussions or brass sections, being "capable of producing over
> 40 acoustic watts".
It is well known that dynamic range is specified by the ratio of two
numbers, one being peak level, and the other being residual noise
under identical operating conditions. OK, so we've got a number for
peak level. Where's the number for residual noise under identical
operating conditions?
> The references come from the AES Journal, not from preprints,
> respectively [2] "Dynamic-Range Requirement for Subjectively
> Noise-Free Reproduction of Music", Journal of the Audio
> Engineering Society, Vol 30 7/8, July/August 1982 and [4]
> "Dynamic Range in Digital Audio", Louis D. Fielder, Journal of
> the Audio Engineering Society, Vol. 43 5, May 1995
Notice that the title of this article is not anything like "Dynamic
Range Requirements For Reproducing Music With No Added Audible
Noise". Thus it is irrelevant to the question at hand.
Anybody who listens carefully knows that live music has background
noise associated with it. Therefore any reproduction of live music
will have background noise or it will not sound realistic.
What is desired is therefore not music with no background noise, but
music with no audible added background noise.
It may be unfair to judge Fielder's JAES article as something that
it, in accordance with its title, is not. However, we have a reader
here who is applying it as if it were something it clearly is not,
and so I will analyze it in accordance with how it is being applied.
Fielder's paper starts out with a description of a "Simplified
Recording System" that sets the stage for the discussion that
follows.
Fielder then has a section on "Maximum Level Determination" which is
summarized in table 1 "Peak Levels In Music". This table contains a
maximum level of 128 dB, not the 129 dB claimed above. Higher levels
are described elsewhere in the paper, but were related to "close
micing", which is vastly different from sitting in the audience and
listening to music.
It should be mentioned that all levels in excess of 116 dB mentioned
in Fielder's Table 1 were not achieved with acoustical instruments,
but with electronic amplification. This is critical in itself because
the dynamic range of sound reinforcement (amplification) equipment
used at live concerts is itself limited, typically to far less than
80 dB.
If you get close enough to the electronic musical instruments at a
live performance to escape the usual relatively high ambient noise,
you will usually hear a fair amount of hum and noise coming from the
speakers.
For Fielder's paper to be a proper discussion of the dynamic range
his section about "Maximum Level Determination" would be followed by
a section about "Minimum Level Determination". However no such
discussion appears anyplace in the paper. Instead, discussion shifts
to thresholds of audibility in quiet rooms for white-noise signals.
It should also be pointed out that many of the calculations in
Fielder's paper presume the use of close microphone techniques which
have almost completely fallen out of favor for recording acoustical
music in live venues, because close-micing does not recover the
ambiance of the room.
Fielder's paper's paragraph entitled "Dynamic Range Requirement"
mentions a requirement for 90 dB dynamic range for live music, not
close-miced, and with an audience present. While this may still
overstate the practical requirements, it is the number he presents
that would be most relevant to audiophiles who are trying to recreate
the experience of being at a live performance in their listening
room. 90 dB is also a dynamic range requirement that can easily be
met with linear 16 bit PCM coding, such as is used by the traditional
audio CD.
Therefore the Fielder paper which has been cited above, shows that
audiophiles have no need for a digital system with higher resolution
than that which has been available via the regular audio CD for about
20 years.
François Yves Le Gal
wrote:
>Has anyone checked out these numbers?
They are 100 % consistent with what has already been published on this
subject.
>I question the ability of human lungs to put out 35 watts.
The lungs don't put out 35 w, the trombone does!
Stewart Pinkerton
>Richard D Pierce wrote:
>
>> There are several opinions and incorrect assumptions stated as
>> fact here.
>>
>> In article <atdgmj$uaj$1...@bourbaki.localdomain>,
>> Fran=E7ois Yves Le Gal <fle...@aingeal.com> wrote:
>> >How loud are 40 acoustic watts? Well, around 128 dB spl...
>>
>> At what distance? At 1 meter, yes, 40 acoustic watts produces
>> a sound pressure level of 128 dB SPL assuming omnidirectional
>> radiation. Please enumerate the listening venues which result in
>> sitting 1 meter away from a sound source radiating 40 acoustic
>> watts.
>
>The most obvious one is the guy sitting in the band the row in front of
>the row of 'bones...
>
>Now, the people *dancing* in front of the *row* of 'bones, trumpets
>and sax's... or in the front row in the club...
>
>Guess it never happens...
It certainly never happens if you want to hear a properly balanced
sound of the *whole* band. Incidentally, since the noise floor in such
a club will be around 60-70dB at the quietest, we still don't need
much of a dynamic range................................
--
Stewart Pinkerton | Music is Art - Audio is Engineering
Stewart Pinkerton
wrote:
>On 13 Dec 2002 23:17:15 GMT, DPi...@TheWorld.com (Richard D Pierce)
>wrote:
>
>>The
>>dynamic range requirements may well be needed, they may not. But
>>this is a lousy way to attempt to prove it.
>
>Well, Mr. Pierce, you haven't addressed the rest of my post, only
>dealing with one reference out of thirteen. You stated in your opening
>remarks that "[t]here [were] several opinions and incorrect assumptions
>stated as fact here".
>
>You've only addressed *one* so far, and your arguments have been fully
>refuted. So let me ask, again, what are the other points? If I may say
>so, your post is a very lousy way to attempt disproving mine.
There is of course another glaring blunder in one of your references,
where it's claimed that a higher resolution digital system would
answer problems of CD sounding unlike vinyl. The author seems to have
conveniently ignored the glaringly obvious fact that vinyl has some
20-30dB *less* dynamic range than CD, so clearly a lack of dynamic
range on CD is *not* what causes a minority preference for the
distinctive sound of vinyl. Given that degree of basic incompetence,
the credibility of the rest of that reference is destroyed.
>Anyway, as all supplied references demonstrate, CD is only able to
>present a reasonable fac-simile of the actual musical event. High
>resolution digital systems are required in order to approach a higher
>fidelity to the actual musical event.
So you claim, and yet I am not aware of *any* domestic hi-fi system
which can even approach 90dB dynamic range, let alone anything higher
than the 93dB offered by CD. So, what's the point of SACD?
Arny Krueger
news:atilrf$cis$1...@bourbaki.localdomain
> On 15 Dec 2002 18:17:51 GMT, "normanstrong"
> <norman...@attbi.com> wrote:
>
>> Has anyone checked out these numbers?
>
> They are 100 % consistent with what has already been published on
> this subject.
>> I question the ability of human lungs to put out 35 watts.
The question is valid. As I've shown in another post François has
apparently not noticed that some of the numbers in the AES article he
cited were for electronically-assisted musical instruments and others
were for close-miced musical instruments. Close micing of a brass
instrument can involve placing the microphone inside the instrument
where the sonic energy is very concentrated.
> The lungs don't put out 35 w, the trombone does!
François, please allow me to refresh your understanding of the law of
conservation of energy.
A trumpet has only one significant energy source, and that is the
lungs of person playing it.
Stewart Pinkerton
<fle...@aingeal.com> wrote:
>On 15 Dec 2002 18:17:51 GMT, "normanstrong" <norman...@attbi.com>
>wrote:
>
>>Has anyone checked out these numbers?
>
>They are 100 % consistent with what has already been published on this
>subject.
Unfortunately, as Arny has already demonstrated, the Fielder paper is
fatally flawed, and is totally unrelated to *real* dynamic range
requirements.
>>I question the ability of human lungs to put out 35 watts.
>
>The lungs don't put out 35 w, the trombone does!
What, you think that the trombone has an efficiency of greater than
100%?
Harry Lavo
> On 14 Dec 2002 17:51:56 GMT, "Arny Krueger" <ar...@hotpop.com> wrote:
>
> >Apparently it has become stylish on RAHE to play "Name That Paper".
> >The way this game works is that a profusion of quotes from a
> >scientific paper are quoted without actually naming the paper.
>
> Mr. Krueger, if you had read and understoood my post, you would have
> noticed that all references were duly noted and detailed.
>
> The Johnson and Pflaumer preprint was referred as such, including it's
> complete title in the text: "AES preprint, "Compatible Resolution
> Enhancement in Digital Audio Systems", [1] by Keith O. Johnson, an AES
> Fellow, and Michael W. Pflaumer".
>
> The [1] points to the reference list after my post, where, if you had
> read all of the post, you would have found "[1] "Compatible Resolution
> Enhancement in Digital Audio Systems", Keith O. Johnson and Michael W.
> Pflaumer, Preprint 4392, AES 101, November 1996", a full reference to
> the quoted preprint.
>
Mr. Krueger did the same thing (reply before fully reading) my posting of
the Oohashi
article in the Journal of Neurophysiology a month or so ago. Whether this
is a deliberate tactic or an inordinately defensive reaction only Mr.
Krueger knows. Perhaps he could explain.
>snip< not relevant
François Yves Le Gal
wrote:
>As I've shown in another post Fran=E7ois has
>apparently not noticed that some of the numbers in the AES article he
>cited were for electronically-assisted musical instruments and others
>were for close-miced musical instruments.
Well, you haven't shown anything, Mr. Krueger. A proper refutation of my
arguments would have implied stating the actual paper you address,
supplying significant quotes and, in a nutshell, doing your homework.
Something you've abstained to do, prefering instead to resort to your
usual obfuscating tactics.
Here are the relevant parts, again:
"reproduction of music at natural sound levels requires very high peak
sound levels of up to 129dB spl", with some instruments, such as
percussions or brass sections, being "capable of producing over 40
acoustic watts", Fielder, op. cited.
"By contrast, a single trombone in full song pumps out as much as 35
acoustic watts!", Atkinson, op. cited.
Neither a trombone, nor a horn section or a drum kit can be considered
"electronically-assisted musical instruments" as you so incorrectly
state.
>Close micing of a brass
>instrument can involve placing the microphone inside the instrument
>where the sonic energy is very concentrated.
I don't know what "close micing" is, Mr. Krueger, but I guess that you
meant "close miking". Anyone familiar with recording techniques knows
that you *never* set the mike inside the instrument but a few inches - 4
to 12 - from it's bell.
=20
>A trumpet has only one significant energy source, and that is the
>lungs of person playing it.
Yes, but the person doesn't have to put out all the energy. A trombone
uses a horn and a barrell, it is an instrument transforming and
amplifying energy. Just as a set of pulleys allow you to lift tons of
equipment with one hand. I guess that you should also get back to
basics, Mr. Krueger, maybe beginning with
http://www.necc.mass.edu/MRVIS/MR3_13/start.htm.
François Yves Le Gal
Pinkerton) wrote:
>Unfortunately, as Arny has already demonstrated, the Fielder paper is
>fatally flawed, and is totally unrelated to *real* dynamic range
>requirements.
Mr. Krueger hasn't demonstrated anything. The two papers by Louis
Fielder - which you haven't read - have been peer reviewed and published
in the Journal of the Engineering Audio Society. If you care to refute
them, please do so. Until then, your attempts at demonstration by
repetition will be futile at best.
>What, you think that the trombone has an efficiency of greater than
>100%?
Mr. Pinkerton, thank you for admitting that you don't know how a
trombone works. It is basically a *resonant* column of air, with a
varying path length allowing for different notes to be played. The key
word here is resonant.
A suggested reading: "A Simple Model of the Mechanics of Trombone
Playing", Gitte Ekdahl, Technical Reports from the Royal Institute of
Technology, Stockholm, Sweden, 2001. Or, for high school level doc -
easier to understand - try:
http://www.physicsclassroom.com/Class/sound/soundtoc.html
The Mad Doctor
wrote:
>> Quoting John Atkinson in Stereophile [6]: "Want to talk power? A typical
remember though, in the example above, those human lungs have been
horn loaded by the use of the trombone.
GK
>
>Norm Strong
Howard Ferstler
>=20
> Let me begin by quoting an AES preprint by Keith O. Johnson, an AES
> Fellow, and Michael W. Pflaumer:
> "As the compact disc (CD) has become a widely used medium for
> distribution of high fidelity audio, it has become apparent that its
> sound quality is not as high as original expectations, which were based
> primarily on conventional distortion and frequency response
e
> production of CD's and by fidelity conscious consumers.
> Dissatisfaction with the fidelity of CD digital recordings when compare=
d
> to analog master tapes of the same recording sessions prompted the
> authors to investigate the factors responsible for the loss of fidelity
> and to devise approaches for improving the situation.
> ../...
> The peak dynamic range requirement for professional recording has been
> shown to approach 130 dB [2]. Even conservative estimates produce
I've reviewed a lot of symphonic recordings and I sure have
never encountered dynamic range requirements like the ones
mentioned. Assuming a 30 dB noise floor (extremely quiet),
this means that peak levels would be hitting 150-160 dB. No
musical ensemble gets that loud and lets the audience
members (or performers) come out without hearing damage
unless they are wearing ear plugs. Now, who in blazes goes
to live concerts in order to wear ear plugs?
Typical home listening rooms would have background noise at
50 dB or more, so why on earth do recordings need such a
stupendous dynamic range? Incidentally, I am talking about
large-scale symphonic music. With pop music the range
requirements are often considerably less.
Howard Ferstler
Howard Ferstler
>=20
> >As I've shown in another post Fran=3DE7ois has
> >apparently not noticed that some of the numbers in the AES article he
> >cited were for electronically-assisted musical instruments and others
> >were for close-miced musical instruments.
> Well, you haven't shown anything, Mr. Krueger. A proper refutation of m=
y
> arguments would have implied stating the actual paper you address,
> supplying significant quotes and, in a nutshell, doing your homework.
> Something you've abstained to do, prefering instead to resort to your
> usual obfuscating tactics.
> Here are the relevant parts, again:
> "reproduction of music at natural sound levels requires very high peak
> sound levels of up to 129dB spl", with some instruments, such as
> percussions or brass sections, being "capable of producing over 40
> acoustic watts", Fielder, op. cited.
Maybe at point-blank range, but you certainly will not
achieve levels like this in the good seats in a good hall.
And so you will not need such levels at good seats in a good
home-listening environment, when the need is to simulate a
live-music experience.
> "By contrast, a single trombone in full song pumps out as much as 35
> acoustic watts!", Atkinson, op. cited.
Maybe at point-blank range, but you certainly will not get
levels like this in the good seats in a good hall. And so
you will not need such levels at good seats in a good
home-listening environment.
=20
> Neither a trombone, nor a horn section or a drum kit can be considered
> "electronically-assisted musical instruments" as you so incorrectly
> state.
Yes, but all we have to do in a home listening environment
is simulate levels that would be heard in a large space. Are
you saying that an audio buff would want to listen to a
trombone or drum set playing full tilt in their living room,
and then want to reproduce those same levels with their
hi-fi rig? Well, in that case, I suppose you have a point.
However, those guys better be wearing ear plugs when they do
that listening.
=20
Your entire entry has nothing to do with the kind of sound
levels and dynamic-range requirements found in home
listening situations where the object is to simulate what is
heard from good seats in a good hall.
Howard Ferstler
Arny Krueger
news:atj3fg$mv0$1...@bourbaki.localdomain
>> What, you think that the trombone has an efficiency of greater
>> than 100%?
> Mr. Pinkerton, thank you for admitting that you don't know how a
> trombone works. It is basically a *resonant* column of air, with a
> varying path length allowing for different notes to be played.
Well, at least there is no confusion about the fact that you are
claiming efficiency > 100%, François.
> The key word here is resonant.
The key phrase is "Laws of Physics" which dictates that energy is
conserved.
IOW, if a Trombone were to put out 45 watts of acoustic energy, that
energy must come from some outside source. The major outside source
of energy for a trombone is of course the lungs of the player.
There's no way that anybody can blow that hard. There is also no way
that a single trombone can produce 45 watts of acoustic energy.
The source of your confusion has already been discovered, François.
You've ignored the fact that the paper you've been citing includes
sound levels produced by electronic instruments and sound levels
obtained by close micing.
> A suggested reading: "A Simple Model of the Mechanics of Trombone
> Playing", Gitte Ekdahl, Technical Reports from the Royal
> Institute of Technology, Stockholm, Sweden, 2001. Or, for high
> school level doc - easier to understand - try:
> http://www.physicsclassroom.com/Class/sound/soundtoc.html
Fortunately, this reference does not claim efficiency of > 100% for
musical instruments.
François Yves Le Gal
<fer...@attglobal.net> wrote:
>Your entire entry has nothing to do with the kind of sound
>levels and dynamic-range requirements found in home
>listening situations where the object is to simulate what is
>heard from good seats in a good hall.
On the contrary, my post is all about sound levels, dynamic ranges,
bandwidth and resolution as applied to audio.
All published papers are contrary to your ill-formed *opinion*, please
refer to the references I've supplied, read and understand them, and
then try to properly refute them. Until then, you're expressing an
ill-formed opinion. Period.
Oh, and domestic music reproduction has nothing to do with a simulation
of "what is heard from good seats in a good hall". Simulation? What
about high fidelity?
But we should have expected these kind of remarks from someone
advocating various ugly sweeteners such as DSP-based artificial
reverberation, coupled with loudspeakers with quite peculiar radiation
patterns as well as non linear bandwidth.
After all, you've written: "I did listen to a jazz-combo recording that
almost sounded like the group was in the room", in the context of a Bose
901 listening test...
Denis Sbragion
François Yves Le Gal <fle...@aingeal.com> wrote in
news:atdgmj$uaj$1...@bourbaki.localdomain:
...
> "Filters designed for the higher sampling frequency of 96kHz are used
> to show how all these distortion mechanisms can be reduced by filters
> of similar computational requirements but with a more relaxed
> transition region. This results in either reduced ripple (and hence
> pre-echo) amplitude or in a lower time displacement for the echo.
>
> In both cases the effect is likely to be a reduction in the audibility
> of the echo. A direct effect of the higher sampling rate is that for
> an identical filter design the time displacements will scale inversely
> with sample rate. Hence an improvement can be made just from raising
> the sample rate - even for those who cannot hear above 20kHz."
...
I've read this. It reports a 0.2 dB ripple as being audible. I don't
know if this is true but AFAIK even the first Philips CD 100 used 96
taps optimal digital filters with less than +-0.1 dB ripple in the audio
band. For sure its successor, the Philips CD 104, used filters of this
kind, I still have its internal electrical schema somewhere. I think no
recent CD player, even the cheaper one, uses digital filters with more
than 0.01 dB ripple in the audio band.
Regards,
--
Denis Sbragion
InfoTecna
Tel: +39 0362 805396, Fax: +39 0362 805404
URL: http://www.infotecna.it
Arny Krueger
news:atk4le$f1a$1...@bourbaki.localdomain
> François Yves Le Gal <fle...@aingeal.com> wrote in
> news:atdgmj$uaj$1...@bourbaki.localdomain:
...
>> "Filters designed for the higher sampling frequency of 96kHz are
>> used to show how all these distortion mechanisms can be reduced
>> by filters of similar computational requirements but with a more
>> relaxed transition region. This results in either reduced ripple
>> (and hence pre-echo) amplitude or in a lower time displacement
>> for the echo.
The key phrase here is "computational requirements". If they can only
be met to a limited agree, then a certain amount of slop must be
tolerated, and a high sample rate is a viable means for making it
more tolerable.
But let's remember that François is citing a 1996 paper which is now
more than six years old. That's metaphorically two lifetimes in
digital technology time. Technology marches on! What amounted to be
daunting "computational requirements" in 1996 are routinely solved
today.
>> In both cases the effect is likely to be a reduction in the
>> audibility of the echo. A direct effect of the higher sampling
>> rate is that for an identical filter design the time
>> displacements will scale inversely with sample rate. Hence an
>> improvement can be made just from raising the sample rate - even
>> for those who cannot hear above 20kHz." ...
> I've read this. It reports a 0.2 dB ripple as being audible.
I can't find this in the Johnson/Pflaumer paper but if it's there,
somebody isn't doing their DBTs. No way is 0.2 dB peak-peak passband
ripple audible all by itself. In any case the frequencies at which
the ripple exists needs to be considered.
> I
> don't know if this is true but AFAIK even the first Philips CD
> 100 used 96 taps optimal digital filters with less than +-0.1 dB
> ripple in the audio band. For sure its successor, the Philips CD
> 104, used filters of this kind, I still have its internal
> electrical schema somewhere. I think no recent CD player, even
> the cheaper one, uses digital filters with more than 0.01 dB
> ripple in the audio band.
There are audio CD players that show up on the order of 0.5 dB
passband ripple, but they are very cheap, such as the audio sections
of CDROM drives. Even these have improved substantially over the past
few years.
Given that 100 dB of passband ripple is audibly indistinguishable to
virtually all listeners when it is restricted to frequencies > 16
KHz, this whole passband ripple issue needs to be looked in the light
of the frequencies at which it happens. The audio passband of
ordinary audio CDs has quite a bit of safety margin built into it!
Howard Ferstler
> On Sun, 15 Dec 2002 23:51:53 GMT, Howard Ferstler
> <fer...@attglobal.net> wrote:
>
> >Your entire entry has nothing to do with the kind of sound
> >levels and dynamic-range requirements found in home
> >listening situations where the object is to simulate what is
> >heard from good seats in a good hall.
> On the contrary, my post is all about sound levels, dynamic ranges,
> bandwidth and resolution as applied to audio.
Are you saying that you encounter the kind of sound levels you
describe in your home-listening environment - or would adjust for that
kind of performance if you had equipment that could do the job? You
must have a pretty sound-tight house; else your neighbors would be
habitually calling the police.
> All published papers are contrary to your ill-formed *opinion*, please
> refer to the references I've supplied, read and understand them, and
> then try to properly refute them. Until then, you're expressing an
> ill-formed opinion. Period.
These guys are generally talking about sound pressure levels right
there at the recording microphone and not what an individual would
encounter out in the audience area. Also, they are concerned with
having a very wide dynamic range, in order to give themselves a lot of
working headroom. A wider dynamic range capability with recording
hardware reduces the chance of input overload or accidental background
noise from the electronics. It makes the job easier.
> Oh, and domestic music reproduction has nothing to do with a simulation
> of "what is heard from good seats in a good hall". Simulation? What
> about high fidelity?
All recordings are a simulation. With a lot of recordings (certainly
most classical and acoustic jazz), the idea is to simulate the sound
of the original performance. No original performance I have
encountered had the kind of dynamic range out in the audience area
that you describe. If it did, everyone would have to wear ear plugs.
> But we should have expected these kind of remarks from someone
> advocating various ugly sweeteners such as DSP-based artificial
> reverberation, coupled with loudspeakers with quite peculiar radiation
> patterns as well as non linear bandwidth.
Since two-channel recordings are themselves seriously flawed, I see
nothing wrong with applying DSP ambiance synthesis or ambiance
extraction to simulate hall reverb or a discrete center channel.
As for those "quite peculiar radiation patterns," I happen to prefer
systems that have a very wide and uniform broad-bandwidth radiation
pattern. I see nothing wrong with using speakers that deliver such
performance. They most certainly have an edge over speakers that have
very wide off-axis response characterists that resemble a saw blade.
This is not to say that more directional speakers cannot work. I have
reviewed systems like that and was favorably impressed. How well
either approach works will depend upon the listening room, the
recordings being listened to, and listener taste.
Regarding the non-linear bandwidth, I'd like to know just what you
mean. I have measured my main speakers a number of times, and they
more than hold their own with the best of the other speakers I have
reviewed for magazine publication. Indeed, they have the flattest
overall room response curve I have encountered.
> After all, you've written: "I did listen to a jazz-combo recording that
> almost sounded like the group was in the room", in the context of a Bose
> 901 listening test...
Yes, with that particular recording the 901s matched up very well.
They were not that good with some other recordings, however. The point
was that speakers, rooms, and recordings are very complex items that
can do some unpredictable (and often pleasant) things when working
together. I suggest you read my entire The Sensible Sound commentary
on the Bose 901 (issue 86, June/July, 2001) before you condemn my
conclusions.
Howard Ferstler
François Yves Le Gal
Ferstler) wrote:
>These guys are generally talking about sound pressure levels right
>there at the recording microphone and not what an individual would
>encounter out in the audience area.
You've not read any of the supplied refercens, Mr. Ferstler, because, if
you had, you wouldn't post yet another false opinion.
<SNIP> the usual ramblings.
>Since two-channel recordings are themselves seriously flawed, I see
>nothing wrong with applying DSP ambiance synthesis or ambiance
>extraction to simulate hall reverb or a discrete center channel.
Then you're not talking about high fidelity, Mr. Ferstler, as you
*modofy* what's on the recording in order to get what you believe are
stisfying results with your sub par gear.
Just try a real system, and you won't need any more of those distorting
gizmos you so much love. Or maybe not, if your tastes lean towards 100%
artificial and sweetened sound.
In any case, I don't feel you're qualified as an equipment or record
reviewer.
Richard D Pierce
Well, kind sir, unless you can show that a trombone violates the
basic principle of the conservation of energy, then your
statement above is simply absurd.
Indeed, unless you can show that a trombone is 100% efficient
(it is not), then the lungs MUST put out MORE than 35 watts in
order for the trombone to produce 35 watts.
Thus, for a tromobone to produce 35 acoustic watts, the lungs
MUST produce power in excess of 35 watts.
Show that this can be done.
Here's a hint: power, in terms of fundamental units, is
measured as the product of force times velocity, specifically,
P = nt m/s
where P is power in watts, nt is force in Newtons, m is distance
in meters and s is time in seconds. Indeed, a watt is DEFINED as
1 Newton-meter per second.
Now, the trombone is an example of essentially a horn-loaded,
tuned pneumatic modulator, and NO ONE of any credibility
has demonstrated a device where power out exceed power in. Your
statement above:
"The lungs don't put out 35 w, the trombone does!"
stands in stark contrast against this basic tenent of physics
and thus, without extraordinary proof, can be dismissed
outright (unless of course, your statement is incomplete, and
you meant to say "the lungs don't put out 35 w, the tromobone
does, but to do so, the lungs must put out MORE than 35 w." But
your didn't.)
Now, we have two quantities of a pneumatic system available to
us: pressure and flow rate. Pressure is measured in force per
unit area:
p = nt / m^2
where p (more properly, rho) is the pressure, nt is, again, the
force in Newtons, and m^2 is the area in square meters. Flow is
meaured as:
f = m^3 / s
where f is the flow rate, m^3 is the volume in cubic meters and
s is time in seconds. Now, the PRODUCT of pressure and flow
rate:
p * f
expanded:
nt / m^2 * m^3 / s
simplified, becomes:
nt m / s
which is, in fact, identical to the formula for power.
So, unless those making the claim of trombone producing 35 watts
of acoustic power can show that the product of the maximum
sustained pressure AND the maximum sustained flow rate of the
lungs SIMULTANEOUSLY is in excess of 35 watts OR explain why
trombones are exempt from the conservation law of energy, their
claim becomes highly suspect.
Now, in fact, the lungs MAY WELL be capable of that. But unless
they overcome that hurdle, the claim is bogus, pure and simple.
The claim, at least by Mr. Atkinson, that implies, at least as
it was quoted, that 128 dB automatically translates into a power
of 40 acoustic watss is simply incorrect. I don't care if it was
written down or not. It is only equivalent to 40 acoustic watts
IF AN ONLY IF it is measured 1 meter away from an acoustically
small source that is radiating omnidirectionally.
Can one similarily claim that 128 dB produced in a headphone is
ALSO the result of 40 acoustic watts, especially when the
electrical input to the headphone is on the order of 500
milliwatts? If your answer is yes, then it is as absurd on its
face as the claim.
"The lungs don't put out 35 w, the trombone does!"
--
Stewart Pinkerton
Which will affect the dispersion and the coupling to the room air,
*not* the gross power output. Basically, Atkinson miscalculated.
Stewart Pinkerton
<fle...@aingeal.com> wrote:
>On Sun, 15 Dec 2002 21:25:00 GMT, pat...@dircon.co.uk (Stewart
>Pinkerton) wrote:
>
>>Unfortunately, as Arny has already demonstrated, the Fielder paper is
>>fatally flawed, and is totally unrelated to *real* dynamic range
>>requirements.
>
>Mr. Krueger hasn't demonstrated anything. The two papers by Louis
>Fielder - which you haven't read - have been peer reviewed and published
>in the Journal of the Engineering Audio Society. If you care to refute
>them, please do so. Until then, your attempts at demonstration by
>repetition will be futile at best.
Francois, the conclusions which *you* have drawn from the paper are
based on such nonsense as comparing max SPLs from close-miked (or
amplified) instruments, with noise levels in empty auditoria. This is
*not* a realistic dynamic range, and if Fielder supports such an
interpretation (which I suspect he does not), then it's fundamentally
the case that he is incorrect for any *real-world* performance.
As previously noted, where are the master recordings with more than
90dB dynamic range?
>>What, you think that the trombone has an efficiency of greater than
>>100%?
>
>Mr. Pinkerton, thank you for admitting that you don't know how a
>trombone works. It is basically a *resonant* column of air, with a
>varying path length allowing for different notes to be played. The key
>word here is resonant.
Francois, thanks for admitting that you don't understand the most
basic laws of physics. The key phrase here is 'conservation of
energy'.
>A suggested reading: "A Simple Model of the Mechanics of Trombone
>Playing", Gitte Ekdahl, Technical Reports from the Royal Institute of
>Technology, Stockholm, Sweden, 2001. Or, for high school level doc -
>easier to understand - try:
>http://www.physicsclassroom.com/Class/sound/soundtoc.html
Shame that you are unable to understand the basic physics behind these
texts. You can't get out more watts than you put in, regardless of the
'Q' of the resonant device - and no human lungs can generate 45 watts.
Clearly, you are not even up to high school level physics............
You obviously have access to excellent library facilities - I suggest
that you make better use of them, and *learn* some basics.
Stewart Pinkerton
<fle...@aingeal.com> wrote:
>On Sun, 15 Dec 2002 23:51:53 GMT, Howard Ferstler
><fer...@attglobal.net> wrote:
>
>>Your entire entry has nothing to do with the kind of sound
>>levels and dynamic-range requirements found in home
>>listening situations where the object is to simulate what is
>>heard from good seats in a good hall.
>
>On the contrary, my post is all about sound levels, dynamic ranges,
>bandwidth and resolution as applied to audio.
Indeed, and based on faulty interpretation, geared to your blinkered
defence of SACD against any and all real-world evidence.
>All published papers are contrary to your ill-formed *opinion*, please
>refer to the references I've supplied, read and understand them, and
>then try to properly refute them.
Perhaps you might also care to *understand* those references, and
translate them to a realistic performance venue - and audience
position.
> Until then, you're expressing an
>ill-formed opinion. Period.
As are you. Period.
François Yves Le Gal
Pinkerton) wrote:
>There is of course another glaring blunder in one of your references,
>where it's claimed that a higher resolution digital system would
>answer problems of CD sounding unlike vinyl.
A proper way of disccussing a reference is to name and properly quote
it, Mr. Pinkerton. As you don't, I'm totally unable to know to what
paper you address.
Getting back to my original post, there is only an incidental mention of
vinyl by J. Tomarakos and C. Duggan in their V48 3 JAES article, where
the authors state that: "many audiophiles claimed that CD-quality audio
lacked a certain warmth that a vinyl groove offered".
There is a huge difference between "the authors claimed" - thus being
accountable for their claim - and "many audiophiles claimed" - a simple
incidental remark, not a statement of position.
If I write "some people prefer wines from Bordeaux", this doesn't mean
that I prefer wines from Bordeaux, Mr. Pinkerton. The blunder is yours,
again.
<SNIP> the rest of the post, which is - again - grossly irrelevant.
Jón Fairbairn
> "Francois Yves Le Gal" <fle...@aingeal.com> wrote in message
> news:atilrf$cis$1...@bourbaki.localdomain
> > The lungs don't put out 35 w, the trombone does!
>
> Francois, please allow me to refresh your understanding of the law of
> conservation of energy.
>
> A trumpet has only one significant energy source, and that is the
> lungs of person playing it.
Just to nitpick (without changing the validity of the argument): since
wind instruments are resonant systems, the peak output power /could/
be greater than that available on the input. Unfortunately for
Fran=E7ois the decay time on a trombone is too short for this to mean
much.
I'm curious to know what the real figures are for brass
instruments. I'm sure that when I was playing the horn ffff I was
putting out about 100W, but most of that would have been as heat...
--
Jon Fairbairn Jon.Fa...@cl.cam.ac.uk
The Mad Doctor
wrote:
>> Quoting John Atkinson in Stereophile [6]: "Want to talk power? A typical
>> moving-coil loudspeaker is around 1% efficient. When you're pinning back
>> your ears with a 100Wpc amp running flat out, the speakers are putting
>> out just two acoustic watts into your listening room. By contrast, a
>> single trombone in full song pumps out as much as 35 acoustic watts!
>> You'd need a 1750Wpc amp to energize the room to the same extent,
>> assuming your speakers didn't go into terminal meltdown.
>
>Has anyone checked out these numbers? I question the ability of human lungs
>to put out 35 watts.
Oh, as an aside, one may be interested to note that we put out about
30 watts just by existing if you look at our thermal output. The form
of energy that that wattage is expressed as varies, but we are able to
produce a fair amount. Converting that efficiently is of course
another story. In the case of a trombone, it is a fairly efficient way
of converting energy from lung, glottal and oral sources into acoustic
energy. Much as a horn loaded speaker has a higher efficiency than one
that is not.
GK
>
>Norm Strong
Howard Ferstler
Yeah, but you do not want to reproduce the sound of a live
trombone in your living room. You want to reproduce the
subjective sound of a trombone in a large concert hall. It
is not necessary for a speaker to generate the kind of
levels you are talking about in order to simulate the
maximum output of a trombone (let alone a symphony
orchestra) in a large hall.
I am utterly baffled by the logic you are applying when you
talk about live-music dynamic range. I have heard compact
discs that had very high peak levels, while at the same time
the only significant background noise was microphone hiss
and the sound of the hall itself. No need for a digital
reproduction system to do any better than that.
Howard Ferstler
Arny Krueger
news:atj3h7$n1o$1...@bourbaki.localdomain
I guess that you are unaware of:
(1) The law of conservation of energy. If a trumpet were to put out
35 watts, the 35 watts must come from some place.
(2) What a horn actually does to sound. A horn does not amplify sound
in the technical sense, since it is a passive device. A hornt simply
improves the efficiency of the source/room energy transformation by
means of acoustical impedance matching.
Howard Ferstler
>
> Richard D Pierce wrote:
>
> > There are several opinions and incorrect assumptions stated as
> > fact here.
> >
> > In article <atdgmj$uaj$1...@bourbaki.localdomain>,
> <snip>
> > >How loud are 40 acoustic watts? Well, around 128 dB spl...
> > At what distance? At 1 meter, yes, 40 acoustic watts produces
> > a sound pressure level of 128 dB SPL assuming omnidirectional
> > radiation. Please enumerate the listening venues which result in
> > sitting 1 meter away from a sound source radiating 40 acoustic
> > watts.
> The most obvious one is the guy sitting in the band the row in front of
> the row of 'bones...
>
> Now, the people *dancing* in front of the *row* of 'bones, trumpets
> and sax's... or in the front row in the club...
>
> Guess it never happens...
I certainly hope the people you are talking about are
wearing ear plugs. After experiencing those kinds of levels
for a moderately long time it is unlikely that any of them
will ever have hearing acuity good enough to appreciate
hi-fi equipment, and they certainly are not going to be able
to appreciate any audio technology with 120 dB worth of
dynamic range.
Howard Ferstler
François Yves Le Gal
<fer...@attglobal.net> wrote:
>I've reviewed a lot of symphonic recordings and I sure have
>never encountered dynamic range requirements like the ones
>mentioned.
If I do understand you properly, Mr. Frestler, you've reviewed a lot of
CD's and never found a 120 dB+ dynamic range. Am I correct here?
François Yves Le Gal
wrote:
>Mr. Krueger did the same thing (reply before fully reading) my posting of
>the Oohashi article in the Journal of Neurophysiology a month or so ago.
He seems to be customary of this quite strange - and non scientific -
behavior and prefers to practice amphigouri, obfuscation as well as ad
nauseam repetition instead of real demonstrations.
Regarding the Oohashi et al. article, "Inaudible High-Frequency Sounds
Affect Brain Activity: Hypersonic Effect", The Journal of
Neurophysiology, V 83 6, June 2000, it is very interesting, even if not
directly audio related. A complete version can be found on the web:
http://jn.physiology.org/cgi/content/full/83/6/3548
IMO, the earlier "High-Frequency Sound above the Audible Range Affects
Brain Electric Activity and Sound Perception", T. Oohashi, E. Nishina,
N. Kawai, Y. Fuwamoto and H. Imai, Preprint 3207, AES 91, October 1991,
is more focused. That's why I've supplied a reference to it, but not to
the JN extended version.
Ed Seedhouse
Doctor) wrote:
>>Has anyone checked out these numbers? I question the ability of human lungs
>>to put out 35 watts.
>remember though, in the example above, those human lungs have been
>horn loaded by the use of the trombone.
Beside the point. The law of conservation of energy dictates that
*no* device can put out more power than is input to it. Period. If
a trombone puts out 35 acoustic watts then it *must* have an input of
at least 35 watts. Actually it would have to be rather higher than
that because the laws of thermodynamics dictate that no device can
have 100% efficiency.
If it comes to betting on someone's opinion versus the known laws of
physics, I know my choice.
Ed Seedhouse
"I'm on my second cup of coffee
and I still can't face the day"
dangling entity
In similar manner, the 35 W bit will only be relevant if the
performance dictates you will be listening to said instruments on-axis
from the flair.
Richard D Pierce
Fine.
Please explain how ANY device can output more power than is put
into it.
Richard D Pierce
François Yves Le Gal <fle...@aingeal.com> wrote:
>On Sun, 15 Dec 2002 21:25:00 GMT, pat...@dircon.co.uk (Stewart
>Pinkerton) wrote:
>>What, you think that the trombone has an efficiency of greater than
>>100%?
>
>Mr. Pinkerton, thank you for admitting that you don't know how a
>trombone works. It is basically a *resonant* column of air, with a
>varying path length allowing for different notes to be played. The key
>word here is resonant.
The keyword to THAT statement is "irrelevant."
Please explain why a resonant column is exempt from the
fundamental law of conservation of energy.
Arny Krueger
news:atism0$hva$1...@bourbaki.localdomain
> Mr. Krueger did the same thing (reply before fully reading) my
> posting of the Oohashi
> article in the Journal of Neurophysiology a month or so ago.
I always appreciate claims of omniscience, because they reveal so
much about the people who write them.
> Whether this is a deliberate tactic or an inordinately defensive
> reaction only Mr. Krueger knows. Perhaps he could explain.
I can explain my confusion quite easily. Questionable writing style.
By adding his own text after the first paragraph without properly
footnoting the first paragraph, François obfuscated the origin of the
first paragraph. He also introduced a kind of punctuation "../..."
which I've do recall ever seeing used before or since.
However attempts to distract the discussion like this do not change
the crucial facts of the matter. The paper in question attempted to
justify a technology that failed in the marketplace because it did
not address widely-perceived consumer needs. The paper made a number
of claims that are highly questionable.
This is a another logical tie between the paper he cited and the
paper you cited, Harry.
Again, the basic technology, HDCD appears to have worked as claimed,
and did in fact produce a technically significant dynamic range
enhancement. Regrettably it was a solution looking for a problem that
was not widely perceived.
Perhaps the lesson we should draw from the HDCD experience is that it
takes about 6 years for a misapplied technology to clearly fail in
the audio marketplace. If that's the case, then we are two years into
this process with SACD and DVD-A.
François Yves Le Gal
wrote:
>Well, at least there is no confusion about the fact that you are
>claiming efficiency > 100%, Fran=E7ois.
I've never claimed efficiency > 100%, Mr. Krueger (and I don't authorize
you to go on a first name basis with me). Care to prove this by
supplying a relevant quote in one of my posts?
>IOW, if a Trombone were to put out 45 watts of acoustic energy, that
>energy must come from some outside source.
Again, I've never stated that a trombone did put out 45 acoustic watts.
Care to prove this by supplying a relevant quote in one of my posts?
>The source of your confusion has already been discovered, Fran=E7ois.
>You've ignored the fact that the paper you've been citing includes
>sound levels produced by electronic instruments and sound levels
>obtained by close micing.
"Close micing", again. You've really got a problem with mice, Mr.
Krueger.
I've quoted John Atkinson's description of a recording session, where he
states that "By contrast, a single trombone in full song pumps out as
much as 35 acoustic watts!". His figures are very close to those
supplied by Louis Fielder, who has demonstrated earlier that the
"reproduction of music at natural sound levels requires very high peak
sound levels of up to 129dB spl", with some instruments, such as
percussions or brass sections, being "capable of producing over 40
acoustic watts".
Nowhere are mentioned electronic instruments or sound levels obtained by
"micing", "ratting" or whatever. NOWHERE.
Here are the references, again: "Jump'n'Jive & the Absolute Sound",
John Atkinson, Stereophile, XXV/7, July 2002, "Dynamic-Range Requirement
for Subjectively Noise-Free Reproduction of Music", Journal of the Audio
Engineering Society, Vol 30 7/8, July/August 1982 and "Dynamic Range in
Digital Audio", Louis D. Fielder, Journal of the Audio Engineering
Society, Vol. 43 5, May 1995.
Now it's time to put up or shut up, Mr. Krueger : either you supply
quotes from these three papers backing your position or you stop
misquoting me - as well as others - and stop twisting reality as you see
fit. Simple, huh?
Denis Sbragion
"Arny Krueger" <ar...@hotpop.com> wrote in news:atkbsl$k0u$1
@bourbaki.localdomain:
..
>> I've read this. It reports a 0.2 dB ripple as being audible.
>
> I can't find this in the Johnson/Pflaumer paper but if it's there,
> somebody isn't doing their DBTs. No way is 0.2 dB peak-peak passband
> ripple audible all by itself. In any case the frequencies at which
> the ripple exists needs to be considered.
thanks for the infos. I suspected this. May be also I've misread the
article, anyway I think the issue isn't even worth a second read.
> There are audio CD players that show up on the order of 0.5 dB
> passband ripple, but they are very cheap, such as the audio sections
> of CDROM drives. Even these have improved substantially over the past
> few years.
I was thinking about standard HiFi CD Players. I hope there ins't such a
bad HiFi CD Player to show 0.5 dB of passband ripple.
> Given that 100 dB of passband ripple is audibly indistinguishable to
> virtually all listeners when it is restricted to frequencies > 16
> KHz, this whole passband ripple issue needs to be looked in the light
> of the frequencies at which it happens. The audio passband of
> ordinary audio CDs has quite a bit of safety margin built into it!
Yep, I completely agree.
Regards,
P.S. My compliments and my thanks for all your great work on the pcabx
and pcavtech sites.
Norbert Hahn
>I've reviewed a lot of symphonic recordings and I sure have
>never encountered dynamic range requirements like the ones
>mentioned. Assuming a 30 dB noise floor (extremely quiet),
Let's assume a 10 dB attenuation of a head phone you can then
easily achieve 110 dB s/n ratio with the maximum set at insane
levels. This attenuation of environmental noise of a head phone
is highly dependend on the frequency and my number is a rough
guess.
Although I never use the maximum SPL my head phones can produce,
I can easily hear a difference in the noise level of two different
soundcards in my computer: a SB Live! compared to a MIA-24.
The Live! outputs mainly hiss, but due to limitations in my
head phone amp I don't hear any noise coming out of the MIA.
Norbert
John Atkinson
news:<atj3h7$n1o$1...@bourbaki.localdomain>...
> wrote:
> >> Quoting John Atkinson in Stereophile [6]: "Want to talk power? A typical
> >> moving-coil loudspeaker is around 1% efficient. When you're pinning back
> >> your ears with a 100Wpc amp running flat out, the speakers are putting
> >> single trombone in full song pumps out as much as 35 acoustic watts!
> >> assuming your speakers didn't go into terminal meltdown.
> >
> >Has anyone checked out these numbers? I question the ability of human lungs
> >to put out 35 watts.
>
> remember though, in the example above, those human lungs have been
> horn loaded by the use of the trombone.
but I will recheck with other sources.
John Atkinson
Editor, Stereophile
Norbert Hahn
>I've reviewed a lot of symphonic recordings and I sure have
>never encountered dynamic range requirements like the ones
>mentioned. Assuming a 30 dB noise floor (extremely quiet),
>this means that peak levels would be hitting 150-160 dB. No
>musical ensemble gets that loud and lets the audience
[...]
Another point hasn't been discussed here: The signals of loud
musical instruments such as brass or percussion are far from
sinusoidal, hence you need a lot more s/n ratio in a real
world compared to the ratio of maximum power vs. ambient noise:
A long time ago I recorded a concert on two reel to reel tape
recorders, one of them had the recording level set too low.
However, when it came to a trumpet duo, the recorder with
the "correct" setting of the volume level recorded with lots
of distortion, while the other recorder did it fine. I checked
the signal with an oscilloscope and found very high short peaks
(+26 dB above average) during the trumpet duo.
That's for the top end. And at the bottom? How does the spectrum
of the noise floor of a typical room, say living room, say studio
look like? Is it white? I haven't checked yet, but I don't think
so.
Shouldn't the noise of any recording system be below that of the
ambient noise with respect of its spectrum? After we're set on
that we can start to define the s/n ratio of a recording system.
Norbert
François Yves Le Gal
> Where's the number for residual noise under identical
>operating conditions?
This question is *totally* irrelevant in this context, Mr. Krueger.
We're discussing peak levels, not dynamic ranges at this time.
>Notice that the title of this article is not anything like "Dynamic
>Range Requirements For Reproducing Music With No Added Audible
>Noise". Thus it is irrelevant to the question at hand.
I've quoted *TWO* articles, not one, with their titles being,
respectively, ""Dynamic-Range Requirement for Subjectively Noise-Free
Reproduction of Music" and "Dynamic Range in Digital Audio". Both are
very highly relevant here. Mr. Krueger seems to have perused only one,
and builds his ill-founded demonstration on a couple of figures.
>It may be unfair to judge Fielder's JAES article as something that
>it, in accordance with its title, is not. However, we have a reader
>here who is applying it as if it were something it clearly is not,
>and so I will analyze it in accordance with how it is being applied.
Please rephrase in English, Mr. Krueger, as I'm - and I believe others
are - unable to understand what you meant.
Mr. Krueger, if you want to refute Mr. Fielder's papers, please read and
understand them first, then quote relevant parts supplying full
references. Your ramblings aren't a refutation, but yet another attempt
at obfuscation.
François Yves Le Gal
<jon.fa...@cl.cam.ac.uk> wrote:
>Unfortunately for
>Fran=3DE7ois the decay time on a trombone is too short for this to mean
>much.
Hint: think wideband in, narrow band out.
>I'm curious to know what the real figures are for brass
>instruments.
Please refer to the Fielder paper I've cited.
Howard Ferstler
>=20>=20
> >These guys are generally talking about sound pressure levels right
> >there at the recording microphone and not what an individual would
> >encounter out in the audience area.
> You've not read any of the supplied refercens, Mr. Ferstler, because, i=
f
> you had, you wouldn't post yet another false opinion.
I do not need to read the references to know that the
dynamic range levels you note are not what anybody
encounters, either at live performances or during
home-listening situations where the dynamic contrasts may be
quite extreme. If you think that the dynamic range of music
hits those extremes in live concert musical situations you
need to recalibrate your SPL meter.
> <SNIP> the usual ramblings.
=20
> >Since two-channel recordings are themselves seriously flawed, I see
> >nothing wrong with applying DSP ambiance synthesis or ambiance
> >extraction to simulate hall reverb or a discrete center channel.
=20
> Then you're not talking about high fidelity, Mr. Ferstler, as you
> *modofy* what's on the recording in order to get what you believe are
> stisfying results with your sub par gear.
Two-channel recordings are compromises from the word go.
With them, true high-fidelity playback, in the sense of
simulating a live-music listening space, is an
impossibility. Hence, some of us do a bit of DSP ambiance
simulation or extraction to fake things enough to get us
closer to what a real performance would sound like.
Fortunately, these days something like Dolby Pro Logic II
allows even those on relative shoestring budgets to get
decent results, at least if they have a good and properly
positioned center-channel speaker and properly positioned
surround speakers.
=20
> Just try a real system, and you won't need any more of those distorting
> gizmos you so much love.=20
It does not matter how good the gear is. If the playback
medium is two-channel stereo you are not getting
cutting-edge high-fidelity sound.=20
As for "real" systems, in the high-end tradition, the
upcoming edition of The Audiophile Voice has my reviews of
the new and very impressive NHT Evolution package: M6
satellites, two W1 subwoofers, and the NHT amps and
electronic crossover. The current issue of The Sensible
Sound has my review of the fine Triad InRoom Silver package
(including their outboard amps and crossover). Reviews of
the Eminent Technology LFT-8 and Polk LSi-25 will be in the
next issue. In the past I have also reviewed the Dunlavy
Cantatas and SC-II systems, and the Waveform MC/MC.1 sub/sat
package, as well as serious systems built by Coincident
Technology, AR, and EOSS, and during my evaluations I have
powered some of those systems with Sherbourn and
Lexicon/Bryston amps, and even used Dunlavy LCR ultra
speaker cables with the stereo pairs. Processors and preamps
have included the Lexicon DC-1, Parasound AVC-2500, and
Sunfire Theater Grand III, and receivers and integrated amps
have included the Yamaha DSP-A1 and RX-Z1. My current
reference DVD player is an Onkyo DV-S939, but I have six
more on hand that deliver DD, DTS, and CD sound that is just
as good.
My own main-system speakers are Allison IC-20s, supported at
the very bottom by a Velodyne F1800RII, and although they
are past ten years of age they easily hold their own, and
then some, when compared to any of those other speaker
pairs. My Carver M500 amp, which is pushing 20 years of age,
also has continued to sound as good as any other amps I have
reviewed.
So, while my current array of gear may seem sub par to you,
it is not sub par compared to the other stuff I mention and
have closely compared it to. I do not know what you use, but
my guess is that it is not one whit better than my better
stuff, and is probably no better than any of the other gear
I have mentioned, either.
> In any case, I don't feel you're qualified as an equipment or record
> reviewer.
Fortunately, you are neither my editor, nor my publisher. I
should also point out that three different book publishers
(one of them did two of my books) have felt that I was
qualified to write about audio, at least on the consumer
level, and recently the editors of the upcoming revised
edition of The Encyclopedia of Recorded Sound (to be
published by Routledge later next year) felt that I knew
enough about audio and audio notables to choose me to write
and edit additional articles.
Those guys may not be up to your standards, but the fact is
that I got the work, and continue to get it.
Howard Ferstler
François Yves Le Gal
Pinkerton) wrote:
>Basically, Atkinson miscalculated.
Sure, if you say so. Then Mr. Fielder also miscalculated, and the
referees of the Journal of the Audio Engineering Society miscalculated,
everybody miscalculated except you and a couple of your friends, Mr.
Pinkerton.
Thank you for setting this matter straight, I'm eagerly awaiting for
your definitive paper in the JAES. Not.
Howard Ferstler
>=20
> >I've reviewed a lot of symphonic recordings and I sure have
> >never encountered dynamic range requirements like the ones
> >mentioned.
> If I do understand you properly, Mr. Frestler, you've reviewed a lot of
> CD's and never found a 120 dB+ dynamic range. Am I correct here?
Well, no CD can achieve that range, but neither can music
listened to in typical concert-hall settings at the good
listening positions. (You might be able to get that if you
sat right in front of the trumpet section, but that is not
my idea of the best seat in the house.) I have played CDs at
very high peak levels (normally, I do not do this, but I
sometimes sacrifice for my readers) and there was no
significant background noise during the quiet passages.
Well, there were hall noises, but those are unrelated to the
digital noise we are supposedly talking about.
I would like to know what live concert you attended where
the dynamic range of the program maxed out at 120+ dB. Rock
concerts do not count, although since the audience is
typically making a huge amount of noise, anyway, the chance
of getting much of a dynamic range there would be nearly
zero. They do hit pretty high peak levels, however. Is that
what you are talking about? And where did you hear that kind
of range with a classical ensemble? They must have been a
pretty energetic group, and the hall must have been as quiet
as the inside of a tomb.
Howard Ferstler
Richard D Pierce
John Atkinson <Stereophi...@Compuserve.com> wrote:
>> >Has anyone checked out these numbers? I question the ability of human lungs
>> >to put out 35 watts.
>>
>> remember though, in the example above, those human lungs have been
>> horn loaded by the use of the trombone.
>
>I got the 35W figure from a magazine article (not Stereophile, please note),
>but I will recheck with other sources.
Here's the derivation of what is possibly the mistake, one
which, regrettably, has been made by a number of people.
The "reference SPL," 0 dB SPL, has been defined as that sound
pressure corresponding to 10^-12 Watt/m^2 (that's a trillionth
of a Watt per square meter). If an acoustically small,
omnidirectional sound source is radiating 1 acoustic watt, what
is the sound pressure 1 meter away from that source? (by "small"
we mean that it is MUCH smaller than the wavelength being
radiated and, in this case, MUCH smaller than 1 meter)
Simple: that 1 watt is, by the very definition of the problem,
evenly distributed across the surface of a sphere whose radius
is 1 meter. The surface area of that sphere 4 pi r^2 or, in our
case here, 12.57 square meters. The power per unit area is,
then, 1 Watt/12.57 m^2 or .0795 Watts/m^2. Referenced to our 0
0dB sound pressure level of 10^-12 watts per square meter, that
results in:
dB SPL = 10 log (7.95 * 10^2 W/m^2 / 10^-12 W/M^2)
dB SPL = 10 log (7.95 * 10^10)
dB SPL = 109 dB
So, someone then went and measured a sound pressure level of
128 dB SPL and then ASSUMED that since there is a difference of
19 dB, the corresponding power MUST be 19 dB higher (hmmm...)
Unfortunately, this conclusion is based on some very specific
assumptions:
1. The measuring distance was 1 meter
2. The source was acoustically small
3. The source was radiating omnidirectionally.
Well:
1a. We do NOT know what the distance was.
2a. Horns ARE NOT acoustically small at the wavelengths they
are operating at.
3a. Horns ARE NOT omnidirectional radiators.
We can't make any guess about condition 1a, but conditions 2a
and 3a BOTH result in much smaller acoustic powers necessary to
generate the same sound pressure level.
One cannot, thus, merely assume that a sound source at any
arbitrary (and, in this case, unknown) distance that is
acoustically large AND not omidirectional is emitting the kinds
of powers claimed.
François Yves Le Gal
Pinkerton) wrote:
>the conclusions which *you* have drawn from the paper are
>based on such nonsense as comparing max SPLs from close-miked (or
>amplified) instruments, with noise levels in empty auditoria.
Which conclusions? I've quoted Mr. Fielder's findings and conclusions.
You've not even *READ* the papers, so your remarks are *totally* silly.
Here are the references of the relevant articles, again:
"Dynamic-Range Requirement for Subjectively Noise-Free Reproduction of
Music", Journal of the Audio Engineering Society, Vol 30 7/8,
July/August 1982; summarized in "Human Auditory Capabilities and Their
Consequences in Digital-Audio Converter Design," AES 7th International
Conference, Toronto, Paper 4A, May 1989
"The Spectral Amplitude Distribution of Selected Compact Discs," R. A
Greiner and Jeff Eggers, Jouranl of the Audio Engineering Society, Vol
37 4, April 1989
"Dynamic Range in Digital Audio", Louis D. Fielder, Journal of the Audio
Engineering Society, Vol. 43 5, May 1995
>thanks for admitting that you don't understand the most
>basic laws of physics. The key phrase here is 'conservation of
>energy'.
Please apply conservation of energy to a resonant, narrow bandwith
system, using a wide bandwith stimuli at the input. Then get back here
and present your apologies for being wrong once again.
>Shame that you are unable to understand the basic physics behind these
>texts.
Ad hominem.
>Clearly, you are not even up to high school level physics............
More ad hominem.
>You obviously have access to excellent library facilities - I suggest
>that you make better use of them, and *learn* some basics.
Yet more ad hominem.
>You can't get out more watts than you put in, regardless of the
>'Q' of the resonant device - and no human lungs can generate 45 watts.
And another falsification, as nowhere in the references or in my posts
was 45 watts mentioned.
François Yves Le Gal
wrote:
>The keyword to THAT statement is "irrelevant."
No it's not, Mr. Pierce. It is very relevant.
>Please explain why a resonant column is exempt from the
>fundamental law of conservation of energy.
Where did I write that it was exempt from it? Supply the actual quote
and the actual post if you can. I very much doubt you'll be able to, as
I've never written anything ever remotely close to that.
François Yves Le Gal
wrote:
>>The lungs don't put out 35 w, the trombone does!
>Well, kind sir, unless you can show that a trombone violates the
>basic principle of the conservation of energy, then your
>statement above is simply absurd.
Well, Mr. Pierce, my statement is semantically and physically correct.
Semantically because the source of the sound isn't the person playing,
but the instrument.
Scientifically because a trombone is a resonant device where the wide
band breath of the player excites a limited bandwidth column of air.
I've already supplied a link explaining in nearly layman's terms how a
trombone - or similar instrument works. Here it is again:
http://www.physicsclassroom.com/Class/sound/soundtoc.html
Another suggested reading: "Fundamentals of musical acoustics", Arthur
H. Benade, Oxford University Press, 1976
>So, unless those making the claim of trombone producing 35 watts
>of acoustic power can show that the product of the maximum
>sustained pressure AND the maximum sustained flow rate of the
>lungs SIMULTANEOUSLY is in excess of 35 watts OR explain why
>trombones are exempt from the conservation law of energy, their
>claim becomes highly suspect.
Nonsense. Where have you read that the 35 watts figure was sustained,
i.e. continuous?
>The claim, at least by Mr. Atkinson, that implies, at least as
>it was quoted, that 128 dB automatically translates into a power
>of 40 acoustic watss is simply incorrect. I don't care if it was
>written down or not.
Well, once again you've not read and understood my post or the various
references supplied, as Mr. Atkinson has never written that a trombone
did produce 40 watts !
Full text:
http://www.stereophile.com/showarchives.cgi?622
This figure comes from Mr. Fielder's paper published in the Journal of
Audio Engineering Society, a peer reviewed publication where the review
committee knows more about the subject that you or I will ever learn.
>It is only equivalent to 40 acoustic watts
>IF AN ONLY IF it is measured 1 meter away from an acoustically
>small source that is radiating omnidirectionally.
And a trombone bell is what? Chopped liver? Or a small source radiating
nearly omnidirectionnally?
> "The lungs don't put out 35 w, the trombone does!"
Yes it does.
François Yves Le Gal
>I can explain my confusion quite easily. Questionable writing style.
Your style?
>By adding his own text after the first paragraph without properly
>footnoting the first paragraph, Fran=E7ois obfuscated the origin of the
>first paragraph.
Please supply the actual quote and the actual post where I'm supposed to
have used your obfuscating tactics, Mr. Krueger. More simply, you didn't
read the papers you've tried to address and hastily fired an answer.
>He also introduced a kind of punctuation "../..."
".../..." is a standard typographical convention equivalent to "[...]".
It means that parts of the text have been deleted.
>which I've do recall ever seeing used before or since.
That's what you call "questionable writing style"? That's what I call
gibberish, and English is only my fourth language.
>Perhaps the lesson we should draw from the HDCD experience is that it
>takes about 6 years for a misapplied technology to clearly fail in
>the audio marketplace.
HDCD hasn't failed, far from it : according to Microsoft, as of december
2000, "HDCD has been used in the recording of more than 5,000 CD titles,
which include more than 250 Billboard Top 200 recordings and more than
175 GRAMMY=AE nominations, .../... and account for more than 300 million
CDs sold".
>If that's the case, then we are two years into
>this process with SACD and DVD-A.
And that's not the case, so you'll be proven wrong once again, Mr.
Krueger.
François Yves Le Gal
Pinkerton) wrote:
>Indeed, and based on faulty interpretation, geared to your blinkered
>defence of SACD against any and all real-world evidence.
Meep. Wrong answer. I'm defending high resolution consumer digital
systems, not SACD. As anyone who has read my posts can attest, except
you, of course, because for whatever silly reason you believe I work for
Sony (I don't, of course).
>Perhaps you might also care to *understand* those references, and
>translate them to a realistic performance venue - and audience
>position.
Translate them to what? Louis Fielder has very clearly established the
requirements of modern digital systems, and CD is unable to cope with
them.
That's the essence of his JAES articles, which you haven't even *read*,
Mr. Pinkerton. So your remark about my understanding of said is
ill-placed, to say the least.
>As are you. Period.
I'm not expressing an opinion, I'm backing a position with dozens of
papers and articles. You and your friends haven't supplied a single
reference backing your neo-luddite claims. Not a single one!
Richard D Pierce
><jon.fa...@cl.cam.ac.uk> wrote:
>
>>Unfortunately for
>>Fran=3DE7ois the decay time on a trombone is too short for this to mean
>>much.
>
>Hint: think wideband in, narrow band out.
Really, Francois? The trumpet is a narrow band instrument? How
can you reconcile this claim from other's claims and
measurements of the spectra of the trumpet?
Between your rather interesting inference of greater than 100%
efficiency and now this claim that the trumpet is a narrow band
instrument, just what is it that you know about such instruments
that invalidates what everyone else seems to know?
François Yves Le Gal
wrote:
>Yeah, but you do not want to reproduce the sound of a live
>trombone in your living room. You want to reproduce the
>subjective sound of a trombone in a large concert hall.
None of the above. I don't want my system to be a limiting factor. I
want it to faithfully transcribe what the artist/producer/... meant. I
don't care about "subjective sound" or artificial sweeteners.
>I am utterly baffled by the logic you are applying when you
>talk about live-music dynamic range.
What logic? I've only supplied relevant quotes from papers published in
reference publications, which clearly establish the needs for more
dynamic range than what's available for CD.
>I have heard compact
>discs that had very high peak levels, while at the same time
>the only significant background noise was microphone hiss
>and the sound of the hall itself.
I very much doubt that you've heard microphone hiss, which is usually
way below a CD's noise floor. And the sound of the hall is part of the
recording.
What would those nice vintage Deccas be without the rumble of the tube
in the distant background of Kingsway Hall?
>No need for a digital
>reproduction system to do any better than that.
Better than what, Mr. Ferstler? Play music on Bose 901's with an added
layer of coloration added by a false reverb in your electronics?
François Yves Le Gal
<fer...@attglobal.net> wrote:
>I do not need to read the references to know that the
>dynamic range levels you note are not what anybody
>encounters
Well, if you had taken the time to read the references, you'd have
noticed that such dynamic ranges are required in order to properly
record and reproduce music.
>Hence, some of us do a bit of DSP ambiance
>simulation or extraction to fake things enough to get us
>closer to what a real performance would sound like.
It's not closer, Mr. Fertsler, it's a travesty of what the
artist/producer/... intended.
>Fortunately, these days something like Dolby Pro Logic II
>allows even those on relative shoestring budgets to get
>decent results, at least if they have a good and properly
>positioned center-channel speaker and properly positioned
>surround speakers.
DPLII doesn't convince me at all on stereo music. It's yet another
gimmick in music mode. Movie mode on DS encoded soudntracks is another
story: DPLII really shines then.
>It does not matter how good the gear is. If the playback
>medium is two-channel stereo you are not getting
>cutting-edge high-fidelity sound.
Then you've *never* listened to a properly setup stereo system.
>As for "real" systems, in the high-end tradition, the
>upcoming edition of The Audiophile Voice has my reviews
<SNIP>
Reviews thru a DSP and in DPLII? Come on, Mr. Ferstler, let's be
serious...
>I do not know what you use, but
>my guess is that it is not one whit better than my better
>stuff, and is probably no better than any of the other gear
>I have mentioned, either.
If you say so.
>Fortunately, you are neither my editor, nor my publisher. I
>should also point out that three different book publishers
>(one of them did two of my books) have felt that I was
>qualified to write about audio, at least on the consumer
>level, and recently the editors of the upcoming revised
>edition of The Encyclopedia of Recorded Sound (to be
>published by Routledge later next year) felt that I knew
>enough about audio and audio notables to choose me to write
>and edit additional articles.
Quoting the excellent Corey Greenberg in Stereophile: "Florida State
University librarian Howard Ferstler has written a book about audio that
has about as much to do with audio reality in the '90s as bell-bottom
pants and "Laugh-In"; High Fidelity Audio/Video Systems is about as
dated and uninformative a how-to book on hi-fi as I've ever read.
Where to begin? How about with the author: in describing himself as an
audiophile and videophile on p.4, Ferstler proudly states that he would
not collect many recordings if it were to be at the expense of building
a fine audio/video system. No, he "would rather listen to a great
recording of a good performance than to a simply good recording of a
great one." To him, "a poor recording ruins the performance, no matter
how good the latter might be. Indeed, how can anyone tell if it was a
fine performance at all if the recording is so muddled that important
characteristics are obscured?" (emphases added)."
And so on...
http://www.stereophile.com/fullarchives.cgi?101
>Those guys may not be up to your standards, but the fact is
>that I got the work, and continue to get it.
Good for you, Mr. Ferstler. Good for you.
Richard D Pierce
>Care to prove this by supplying a relevant quote in one of my posts?
From the archives...
Article: 151097 of rec.audio.high-end
Xref: world rec.audio.high-end:151097
From: François Yves Le Gal <fle...@aingeal.com>
Newsgroups: rec.audio.high-end
Subject: Re: Why high resolution digital systems are ...
Organization: Aingeal.com
Lines: 12
Sender: rdr...@math.berkeley.edu
Approved: rdr...@math.berkeley.edu
Message-ID: <atilrf$cis$1...@bourbaki.localdomain>
X-Original-Date: Sun, 15 Dec 2002 19:32:30 +0100
X-Original-Message-ID: <97ipvu8a6mciptjbm...@4ax.com>
NNTP-Posting-Date: Sun, 15 Dec 2002 19:40:53 GMT
Date: Sun, 15 Dec 2002 19:40:53 GMT
...
>I question the ability of human lungs to put out 35 watts.
The lungs don't put out 35 w, the trombone does!
------------------------------------------------
Ignoring, for the moment, the possible type of "45" vs "35", do
you deny posting the article cited above?
Harry Lavo
news:atlob...@enews1.newsguy.com...
>
> Again, the basic technology, HDCD appears to have worked as claimed,
> and did in fact produce a technically significant dynamic range
> enhancement. Regrettably it was a solution looking for a problem that
> was not widely perceived.
>
> Perhaps the lesson we should draw from the HDCD experience is that it
> takes about 6 years for a misapplied technology to clearly fail in
> the audio marketplace. If that's the case, then we are two years into
> this process with SACD and DVD-A.
>
I don't recall HDCD being advertised at the top of a J&R advertisement, as
is SACD in the J&R advertisement in the January edition of Sound & Vision
magazine. I don't recall HDCD having sections set up for it as have SACD
and DVD-A in Tower Records, Fry's, Best Buy, Circuit City, and Media Play
among others.
The fact that you don't think there is a difference, Arny, doesn't make it
so. There is, and the word is spreading.
Harry Lavo
news:atlm5...@enews1.newsguy.com...
>> BEAR wrote:
>snip<
> > The most obvious one is the guy sitting in the band the row in front of
> > the row of 'bones...
> >
> > Now, the people *dancing* in front of the *row* of 'bones, trumpets
> > and sax's... or in the front row in the club...
> >
> > Guess it never happens...
>
> I certainly hope the people you are talking about are
> wearing ear plugs. After experiencing those kinds of levels
> for a moderately long time it is unlikely that any of them
> will ever have hearing acuity good enough to appreciate
> hi-fi equipment, and they certainly are not going to be able
> to appreciate any audio technology with 120 dB worth of
> dynamic range.
Howard, the article quoted refered to peak levels. That's very different
from sustained levels.
The Mad Doctor
entity) wrote:
>sawb...@uniserve.com (The Mad Doctor) wrote in message news:<atj3h7$n1o$1...@bourbaki.localdomain>...
>> On 15 Dec 2002 18:17:51 GMT, "normanstrong" <norman...@attbi.com>
>> wrote:
>>
>> >> Quoting John Atkinson in Stereophile [6]: "Want to talk power? A typical
>> >> moving-coil loudspeaker is around 1% efficient. When you're pinning back
>> >> your ears with a 100Wpc amp running flat out, the speakers are putting
>> >> out just two acoustic watts into your listening room. By contrast, a
>> >> single trombone in full song pumps out as much as 35 acoustic watts!
>> >> You'd need a 1750Wpc amp to energize the room to the same extent,
>> >> assuming your speakers didn't go into terminal meltdown.
>> >
>> >Has anyone checked out these numbers? I question the ability of human lungs
>> >to put out 35 watts.
>>
>> remember though, in the example above, those human lungs have been
>> horn loaded by the use of the trombone.
>>
>> GK
>> >
>> >Norm Strong
>
>In similar manner, the 35 W bit will only be relevant if the
>performance dictates you will be listening to said instruments on-axis
>from the flair.
Indeed that is true. the horn is only an efficient energy transducer
for that setting, resonance of the sound everywhere else will be based
on the ability of the room to reflect that energy vs. absorb it. and
of course, inverse square drop in energy
GK
Stewart Pinkerton
wrote:
>On Mon, 16 Dec 2002 23:08:46 GMT, pat...@dircon.co.uk (Stewart
>Pinkerton) wrote:
>
>>the conclusions which *you* have drawn from the paper are
>>based on such nonsense as comparing max SPLs from close-miked (or
>>amplified) instruments, with noise levels in empty auditoria.
>
>Which conclusions? I've quoted Mr. Fielder's findings and conclusions.
If (and that's a *big* IF) that is true, then they are fatally flawed,
as previously noted. H
>You've not even *READ* the papers, so your remarks are *totally* silly.
One does not need to read a paper claiming more than 108dB as a
required dynamic range for music reproduction, to know that this is a
risibly unrealistic figure.
As previously asked - but never answered - where is the one single
musical master recording in the entire world which has a dynamic
range greater than 90dB? Well, where is it?
>>thanks for admitting that you don't understand the most
>>basic laws of physics. The key phrase here is 'conservation of
>>energy'.
>
>Please apply conservation of energy to a resonant, narrow bandwith
>system, using a wide bandwith stimuli at the input. Then get back here
>and present your apologies for being wrong once again.
You simply don't know what the heck you're talking about there,
Francois. This is getting quite sad, really. You are attemptijng to
claim that a trombone can put out more power than is input by the
player - this is *impossible*, and has nothing to do with resonant
systems. Don't you even understand what power *is*?
>>Shame that you are unable to understand the basic physics behind these
>>texts.
>
>Ad hominem.
Statement of fact, compounded above.
>>Clearly, you are not even up to high school level physics............
>
>More ad hominem.
Statement of fact, compounded above.
>>You obviously have access to excellent library facilities - I suggest
>>that you make better use of them, and *learn* some basics.
>
>Yet more ad hominem.
No, clearly essential advice.
>>You can't get out more watts than you put in, regardless of the
>>'Q' of the resonant device - and no human lungs can generate 45 watts.
>
>And another falsification, as nowhere in the references or in my posts
>was 45 watts mentioned.
It was mentioned in regard to Atkinson's measurements of the trombone
in question, although the value was of course 35 watts, not 45 as
mistyped above. Just another example of your attempts to slide out of
your errors by use of semantics, since of course you *did* post:
"The lungs don't put out 35 w, the trombone does!"
This is simply incorrect, at the most basic level.
--
Stewart Pinkerton | Music is Art - Audio is Engineering
Stewart Pinkerton
Another typical obfuscation by you, Francois. Fielder's figures have
been cherry-picked by *you*, and do not represent a realistic
situation of a live performance in a real venue. Once again, I am
forced to ask this very simple question, which you keep avoiding:
Where is the one single musical master recording which has a dynamic
range greater than 90dB?
Stewart Pinkerton
wrote:
>On 16 Dec 2002 23:02:55 GMT, Howard Ferstler <fer...@attglobal.net>
>wrote:
>
>>Yeah, but you do not want to reproduce the sound of a live
>>trombone in your living room. You want to reproduce the
>>subjective sound of a trombone in a large concert hall.
>
>None of the above. I don't want my system to be a limiting factor. I
>want it to faithfully transcribe what the artist/producer/... meant. I
>don't care about "subjective sound" or artificial sweeteners.
You seem to be entirely missing the point that the sound of a live
performance in a real performance venue *is* what the artist intended.
>>I am utterly baffled by the logic you are applying when you
>>talk about live-music dynamic range.
>
>What logic? I've only supplied relevant quotes from papers published in
>reference publications, which clearly establish the needs for more
>dynamic range than what's available for CD.
No you have supplied *irrelevant* quotes, as has been pointed out ad
nauseam. Your constant 'calls to authority' in lieu of a rational
argument are becoming tiresome.
>>I have heard compact
>>discs that had very high peak levels, while at the same time
>>the only significant background noise was microphone hiss
>>and the sound of the hall itself.
>
>I very much doubt that you've heard microphone hiss, which is usually
>way below a CD's noise floor.
Only for large capsule mics. Percussion and brass are often recorded
with small mics, which have better HF response but higher self-noise.
Of course, he could also have been hearing tape noise from an analogue
master, as most of the great *performances* have been so recorded.
> And the sound of the hall is part of the recording.
Yes indeed, and Howard just said that he could hear it on CD........
>What would those nice vintage Deccas be without the rumble of the tube
>in the distant background of Kingsway Hall?
Better................
Stewart Pinkerton
wrote:
>On Sun, 15 Dec 2002 19:50:57 GMT, pat...@dircon.co.uk (Stewart
>Pinkerton) wrote:
>
>>There is of course another glaring blunder in one of your references,
>>where it's claimed that a higher resolution digital system would
>>answer problems of CD sounding unlike vinyl.
>
>A proper way of disccussing a reference is to name and properly quote
>it, Mr. Pinkerton. As you don't, I'm totally unable to know to what
>paper you address.
And yet, you quote it below.
>Getting back to my original post, there is only an incidental mention of
>vinyl by J. Tomarakos and C. Duggan in their V48 3 JAES article, where
>the authors state that: "many audiophiles claimed that CD-quality audio
>lacked a certain warmth that a vinyl groove offered".
>
>There is a huge difference between "the authors claimed" - thus being
>accountable for their claim - and "many audiophiles claimed" - a simple
>incidental remark, not a statement of position.
The authors then went on to speculate that higher resolution than CD
might be required to recover this 'warmth', thereby demonstrating a
woeful lack of understanding of the dynamic range limitations of vinyl
(and indeed the analogue master tapes from which that vinyl was cut!).
>If I write "some people prefer wines from Bordeaux", this doesn't mean
>that I prefer wines from Bordeaux, Mr. Pinkerton. The blunder is yours,
>again.
No, the obfuscation is yours, again........
Stewart Pinkerton
wrote:
>On Mon, 16 Dec 2002 23:09:20 GMT, pat...@dircon.co.uk (Stewart
>Pinkerton) wrote:
>
>>Indeed, and based on faulty interpretation, geared to your blinkered
>>defence of SACD against any and all real-world evidence.
>
>Meep. Wrong answer. I'm defending high resolution consumer digital
>systems, not SACD. As anyone who has read my posts can attest, except
>you, of course, because for whatever silly reason you believe I work for
>Sony (I don't, of course).
If it waddles like a duck, and quacks like a duck, then I call it a
duck.......
>>Perhaps you might also care to *understand* those references, and
>>translate them to a realistic performance venue - and audience
>>position.
>
>Translate them to what? Louis Fielder has very clearly established the
>requirements of modern digital systems, and CD is unable to cope with
>them.
Fielder did no such thing, once you transpose his numbers to a
realistic live performance setting - and you know it.
>That's the essence of his JAES articles, which you haven't even *read*,
>Mr. Pinkerton. So your remark about my understanding of said is
>ill-placed, to say the least.
>
>>As are you. Period.
>
>I'm not expressing an opinion, I'm backing a position with dozens of
>papers and articles. You and your friends haven't supplied a single
>reference backing your neo-luddite claims. Not a single one!
No Francois, you blew a lot of smoke regarding particular numbers you
cherry-picked from various documents. You have been told this several
times by several people. Now, answer this very simple question:
Where is the SACD (or DVD-A) with more than 90dB dynamic range?
Just one example will do - otherwise you clearly have no valid
argument, you are just handwaving, and quoting completely artificial
numbers with no relevance to real music performances.
Arny Krueger
news:atm5ih$ta$1...@bourbaki.localdomain
> "Arny Krueger" <ar...@hotpop.com> wrote in message
> news:atlob...@enews1.newsguy.com...
>> Again, the basic technology, HDCD appears to have worked as
>> claimed, and did in fact produce a technically significant
>> dynamic range enhancement. Regrettably it was a solution looking
>> for a problem that was not widely perceived.
>> Perhaps the lesson we should draw from the HDCD experience is
>> that it takes about 6 years for a misapplied technology to
>> clearly fail in the audio marketplace. If that's the case, then
>> we are two years into this process with SACD and DVD-A.
> I don't recall HDCD being advertised at the top of a J&R
> advertisement, as is SACD in the J&R advertisement in the January
> edition of Sound & Vision magazine.
That would relate to advertising, not sonic performance as perceived
by human beings by means of just listening.
> I don't recall HDCD having
> sections set up for it as have SACD and DVD-A in Tower Records,
> Fry's, Best Buy, Circuit City, and Media Play among others.
That would relate to advertising, not sonic performance as perceived
by human beings by just listening.
> The fact that you don't think there is a difference, Arny,
> doesn't make it so.
I never said it did. What I have said is that its darn hard to find
listening tests showing that DVD-A and SACD technology provide
advantages in sonic performance as perceived by human beings by just
listening.
Furthermore, the world of science has repeatedly found over a many
decades that extending reproduction bandwidth > 15-16 KHz is
undetectable by most or all human beings by means of just listening.
There is also considerable evidence that there simply are no
commercial recordings on CD that actually exhaust or come close to
exhausting its dynamic range reserves.
I find it ironic that someone who claims to be a subjectivist seems
to place so much emphasis on advertising, and so little emphasis on
honest attempts to determine whether or not DVD-A and SACD actually
provide advantages in sonic performance as perceived by human beings
by just listening.
> There is, and the word is spreading.
That's what advertising does, it spreads words. I'm more interested
in spreading good-sounding music, which I believe is facilitated by
finding media formats that provide advantages in sonic performance as
perceived by human beings by the means of just listening.
François Yves Le Gal
Pinkerton) wrote:
>You seem to be entirely missing the point that the sound of a live
>performance in a real performance venue *is* what the artist intended.
It is not. Live performances and records are two very different things.
High fidelity is all about faithfully reproducing what's on a record,
not the ambiance of a live venue. Except of course if the record is a
live performance.
>No you have supplied *irrelevant* quotes, as has been pointed out ad
>nauseam. Your constant 'calls to authority' in lieu of a rational
>argument are becoming tiresome.
All of the quotes I've supplied are perfectly relevant, all are based on
research, most have been peer-reviewed and have been published in
reference journals.
Mr. Pinkerton, as you've been unable to refute them, supply any
references or even more than anecdotal facts backing your claims, you
resort to your usual form of demonstration by repetition, constant
falsification, go once again ad hominem and try to attack your opponent.
And you're the one talking about "rational arguments"?
François Yves Le Gal
Atkinson) wrote:
>I got the 35W figure from a magazine article (not Stereophile, please note),
>but I will recheck with other sources.
The 35 acoustics watts is coherent with a 128+ dB SPL level close to the
trombone bell as well as with all litterature on the subject (vide
Fielder's articles in the JAES).
François Yves Le Gal
wrote:
>The trumpet is a narrow band instrument?
Trumpet, which trumpet?
>How
>can you reconcile this claim from other's claims and
>measurements of the spectra of the trumpet?
I dunno, as we're discussing trombones, not trumpets.
>Between your rather interesting inference of greater than 100%
>efficiency
Oh, now that's an inference. And how did you infer that I inferred that
a trombone did show more than 100% efficiency? Please supply the actual
quote and the actual post, thank you.
>and now this claim that the trumpet is a narrow band
>instrument
I've never claimed anything about the trumpet, Mr.Pierce. Try to read
and understand the posts you try to address.
>just what is it that you know about such instruments
>that invalidates what everyone else seems to know?
Well, and what is it that you know about properly understanding posts
before answering them that invalidates what everyone else seems to know?
The Mad Doctor
>On Sun, 15 Dec 2002 23:34:47 GMT, sawb...@uniserve.com (The Mad
>Doctor) wrote:
>
>>>Has anyone checked out these numbers? I question the ability of human lungs
>>>to put out 35 watts.
>
>>remember though, in the example above, those human lungs have been
>>horn loaded by the use of the trombone.
>
>Beside the point. The law of conservation of energy dictates that
>*no* device can put out more power than is input to it. Period. If
>a trombone puts out 35 acoustic watts then it *must* have an input of
>at least 35 watts. Actually it would have to be rather higher than
>that because the laws of thermodynamics dictate that no device can
>have 100% efficiency.
>
>If it comes to betting on someone's opinion versus the known laws of
>physics, I know my choice.
>
For a batch of people who claim to really know their stuff, I would
really like to know where I stated that conserfvation is not obeyed.
my statement is one regarding efficiency. the horn loading makes the
tranducer (the trombone) more efficient.
The lungs are capable of producing prodigious workloads, I would
suggest that forcing breath through a pneumatic transducer would be
more than capable of lighting a greater than 40 watt light bulb, and
that would certainly not be an effective transducer as one would need
to incorporate a windmill structure in the transducer thus introducing
inertia that has to be overcome and a likely drop in efficiency due to
loss of energy by sustained friction.
Certainly a leisurely peddle on a bike can power a television and a
VCR, again with relatively inefficient transducers.
GK
>Ed Seedhouse
>
>"I'm on my second cup of coffee
> and I still can't face the day"
Simon Byrnand
news:atltk...@enews4.newsguy.com...
> On 16 Dec 2002 22:46:39 GMT, DPi...@TheWorld.com (Richard D Pierce)
> wrote:
>
> >>The lungs don't put out 35 w, the trombone does!
>
> >Well, kind sir, unless you can show that a trombone violates the
> >basic principle of the conservation of energy, then your
> >statement above is simply absurd.
>
> Well, Mr. Pierce, my statement is semantically and physically correct.
>
> Semantically because the source of the sound isn't the person playing,
> but the instrument.
But the source of the power is the person playing it. Otherwise, where is
the built in source of power in your trumpet ? Batteries perhaps ?
> Scientifically because a trombone is a resonant device where the wide
> band breath of the player excites a limited bandwidth column of air.
And this has what to do with power in vs power out ?
> Full text:
> http://www.stereophile.com/showarchives.cgi?622
>
> This figure comes from Mr. Fielder's paper published in the Journal of
> Audio Engineering Society, a peer reviewed publication where the review
> committee knows more about the subject that you or I will ever learn.
>
> >It is only equivalent to 40 acoustic watts
> >IF AN ONLY IF it is measured 1 meter away from an acoustically
> >small source that is radiating omnidirectionally.
>
> And a trombone bell is what? Chopped liver? Or a small source radiating
> nearly omnidirectionnally?
Neither.
Omnidirectional means a point source evenly illuminating with sound, an
imaginary sphere surrounding itself. A trumpet doesn't even remotely
resemble this, it directs the majority of its output in a certain direction.
Thus the measured SPL on the axis of this maximum output at a given distance
is much higher for a given accoustic power than an omnidirectional point
source. On the other hand the SPL significantly off axis is much LOWER than
the point source. Accoustic watts do not translate to SPL except in very
specific circumstances. (EG where the directivity of the source and the
measuring distance are known)
> > "The lungs don't put out 35 w, the trombone does!"
>
> Yes it does.
You seem to be in denial here in the face of insurmountable evidence to the
contrary, why not admit a boo-boo and move on....
Regards,
Simon
The Mad Doctor
>"The Mad Doctor" <sawb...@uniserve.com> wrote in message
>news:atj3h7$n1o$1...@bourbaki.localdomain
>
>> On 15 Dec 2002 18:17:51 GMT, "normanstrong"
>> <norman...@attbi.com> wrote:
>
>>> Has anyone checked out these numbers? I question the ability of
>>> human lungs to put out 35 watts.
>
>> remember though, in the example above, those human lungs have been
>> horn loaded by the use of the trombone.
>
>I guess that you are unaware of:
>
>(1) The law of conservation of energy. If a trumpet were to put out
>35 watts, the 35 watts must come from some place.
I am fully aware of the theory of energy conservation, I am also aware
that the amount of work a set of lungs can generate is fairly
prodigious. The trombone is an efficient way of capturing and
converting that work
>
>(2) What a horn actually does to sound. A horn does not amplify sound
>in the technical sense, since it is a passive device. A hornt simply
>improves the efficiency of the source/room energy transformation by
>means of acoustical impedance matching.
I stated in my post that the horn increased the efficiency, what part
of that are you incapable of understanding?
Let's face it, in lay terms, without hiding behind the jargon, the
fact is the lungs are a capable source of work and the horn is an
efficient way of capturing that and converting it into sonic energy.
Nowhere did I state that the theory of energy conservation was not
obeyed. I suggest that you save your assumptions until you have all
the facts.
Grant Kinsley MD
The Mad Doctor
wrote:
>In article <atj3h7$n1o$1...@bourbaki.localdomain>,
>The Mad Doctor <sawb...@uniserve.com> wrote:
>>On 15 Dec 2002 18:17:51 GMT, "normanstrong" <norman...@attbi.com>
>>wrote:
>>
>>>> Quoting John Atkinson in Stereophile [6]: "Want to talk power? A typical
>>>> moving-coil loudspeaker is around 1% efficient. When you're pinning back
>>>> your ears with a 100Wpc amp running flat out, the speakers are putting
>>>> out just two acoustic watts into your listening room. By contrast, a
>>>> single trombone in full song pumps out as much as 35 acoustic watts!
>>>> You'd need a 1750Wpc amp to energize the room to the same extent,
>>>> assuming your speakers didn't go into terminal meltdown.
>>>
>>>Has anyone checked out these numbers? I question the ability of human lungs
>>>to put out 35 watts.
>>
>>remember though, in the example above, those human lungs have been
>>horn loaded by the use of the trombone.
>
>Fine.
>
>Please explain how ANY device can output more power than is put
>into it.
Please show me where I said that the energy is changing, I am simply
saying that the lungs produce that energy (fairly well, the lungs are
powered by a significant set of muscles that include the diaphragm,
the intercostals, the abdominals, and the neck muscles) Next I said
that the horn is an efficient transducer of that energy because of
horn loading. I have no doubt that the human respiratory tract is
capable of producing 35 watts, that is simply not a great amount of
work, a slow bicycle ride can produce enough wattage to run a
television with a much less efficient transducer.
Before assuming, maybe you should read your facts.
François Yves Le Gal
wrote:
>That would relate to advertising, not sonic performance as perceived
>by human beings by means of just listening.
False, Mr. Krueger, all published evidence states the contrary. Refer to
my original post in this thread for a bibliography as well as relevant
extracts..
>Furthermore, the world of science has repeatedly found over a many
>decades that extending reproduction bandwidth > 15-16 KHz is
>undetectable by most or all human beings by means of just listening.
False again, Mr. Krueger, all published evidence states the contrary.
Refer to my original post in this thread for a bibliography as well as
relevant extracts.
Again, a lot of assertions, but no demonstrations. Where are the papers
backing your claims, Mr. Krueger? Nowhere, because you can't find a
single one backing your neo-luddite position.
Arny Krueger
news:atlp0...@enews1.newsguy.com
> Howard Ferstler <fer...@attglobal.net> wrote:
>
>> I've reviewed a lot of symphonic recordings and I sure have
>> never encountered dynamic range requirements like the ones
>> mentioned. Assuming a 30 dB noise floor (extremely quiet),
>> this means that peak levels would be hitting 150-160 dB. No
>> musical ensemble gets that loud and lets the audience [...]
>
> Another point hasn't been discussed here: The signals of loud
> musical instruments such as brass or percussion are far from
> sinusoidal, hence you need a lot more s/n ratio in a real
> world compared to the ratio of maximum power vs. ambient noise:
That is considered in most SNR measurements. Basically, they are
based on the test signal's peak levels. This is implicit in the
demand that the test signal be reproduced without distortion.
> A long time ago I recorded a concert on two reel to reel tape
> recorders, one of them had the recording level set too low.
> However, when it came to a trumpet duo, the recorder with
> the "correct" setting of the volume level recorded with lots
> of distortion, while the other recorder did it fine. I checked
> the signal with an oscilloscope and found very high short peaks
> (+26 dB above average) during the trumpet duo.
> That's for the top end. And at the bottom? How does the spectrum
> of the noise floor of a typical room, say living room, say studio
> look like? Is it white? I haven't checked yet, but I don't think
> so.
The usual model for the noise floor of large rooms is something like
pink or doubly-pinked (red or brown) noise.
> Shouldn't the noise of any recording system be below that of the
> ambient noise with respect of its spectrum? After we're set on
> that we can start to define the s/n ratio of a recording system.
It seems like the way that the human ear responds should be an
important part of the analysis.
Arny Krueger
> Although I never use the maximum SPL my head phones can produce,
> I can easily hear a difference in the noise level of two different
> soundcards in my computer: a SB Live! compared to a MIA-24.
> The Live! outputs mainly hiss, but due to limitations in my
> head phone amp I don't hear any noise coming out of the MIA.
A device that produces "mainly hiss" would have a SNR of no more than
6 dB. A SBLive! has a SNR of far more than 6 dB, therefore it does
not produce "mainly hiss". It produces mainly signal.
I agree that the MIA is a superior product, but the SBLive! is simply
and technically not as bad as being claimed here.
François Yves Le Gal
Pierce) wrote:
>>Again, I've never stated that a trombone did put out 45 acoustic watts.
>>Care to prove this by supplying a relevant quote in one of my posts?
>
From the archives...
../...
> The lungs don't put out 35 w, the trombone does!
> ------------------------------------------------
>Ignoring, for the moment, the possible type of "45" vs "35", do
>you deny posting the article cited above?
Of course I have written and posted the article
<news:atilrf$cis$1...@bourbaki.localdomain>. And of course I've *NEVER*
stated that a trombone did put out 45 acoustic watts. NEVER.
Oh, and I just love your "possible type of '45' vs. '35'", Mr. Pierce.
Selective understatement at his best.
Stewart Pinkerton
<fle...@aingeal.com> wrote:
>On Tue, 17 Dec 2002 09:00:46 GMT, pat...@dircon.co.uk (Stewart
>Pinkerton) wrote:
>
>>You seem to be entirely missing the point that the sound of a live
>>performance in a real performance venue *is* what the artist intended.
>
>It is not. Live performances and records are two very different things.
>High fidelity is all about faithfully reproducing what's on a record,
>not the ambiance of a live venue. Except of course if the record is a
>live performance.
If the recording is not of a live performance, then the question of
'fidelity' is rather moot. It remains the case however, that you have
shown *zero* evidence of the existence of *any* master recording of
music of *any* sort, having a dynamic range in excess of 90dB.
>>No you have supplied *irrelevant* quotes, as has been pointed out ad
>>nauseam. Your constant 'calls to authority' in lieu of a rational
>>argument are becoming tiresome.
>
>All of the quotes I've supplied are perfectly relevant, all are based on
>research, most have been peer-reviewed and have been published in
>reference journals.
They are not relevant to high-fidelity music reproduction, since the
peak SPL and noise floor levels are not taken from the same situation.
In short, your interpretation is flim-flam.
>Mr. Pinkerton, as you've been unable to refute them, supply any
>references or even more than anecdotal facts backing your claims, you
>resort to your usual form of demonstration by repetition, constant
>falsification, go once again ad hominem and try to attack your opponent.
>And you're the one talking about "rational arguments"?
Indeed I am. I refute your fallacious arguments by asking the same
simple question, which you constantly avoid:
Where is the master recording of a musical performance, which exhibits
a dynamic range in excess of 90dB? It's a simple and highly pertinent
question, to which you have no answer.
François Yves Le Gal
wrote:
>Let's face it, in lay terms, without hiding behind the jargon, the
>fact is the lungs are a capable source of work and the horn is an
>efficient way of capturing that and converting it into sonic energy.
Let's say 5 liters of median capacity (singers, divers et al. can reach
8 liters), and a peak flow of up to 500 l/mn for a well trained adult.
Hmmm, 5 liters in 600 ms, that's some energy...
Richard D Pierce
Mr. le Gal's refusal to admit to his misunderstanding of th
fundamental prinmciples involved is achieving legendary status.
Let's examine this particular statement by simply quoting froma
recent reference precisely on this topic.
Note that the PWL [sound power level] is a measure of the
total acoustic energy per unit time emitted by a source. It
CANNOT be converted into SPL until additional information is
provided, in particular, directionality of the source and
distance from the source.
Blackstone, D., Physical Acoustics, Wiley & Sons, 2000
Once can also view the directional characteristics typical of
horn-loaded brss instruments such as the trumpet, trombone and
french horn in figures 6.39 and 6.40 from Olson, H., Music,
Physics and Engineering, Dover 1967, all of which show that
within their ranges, the instruments have radiation patterns
that are FAR from omnidirectional. One finds, for example, that
the output 90 degrees off axis is 10 dB and more down above 900
Hz, The rearward radiation in many cases is more than 30 dB
down.
Mr. le Gal unqualified declaration:
The 35 acoustics watts is coherent with a 128+ dB SPL level
close to the trombone bell as well as with all litterature on
the subject
Is in fact, in the Blackstaock quote, refuted by the very
literature he so desparately invokes for support. What does Mr.
le Gal mean, for example, by "close?" Since sound pressure is a
complex functyion of distance from the source when that distance
is proximal to the size of the radiating source, his claim that
the power is "coherent" [did he mean "consistent" perchance?] is
soundl contradicted by Blackstone.
At this point, Mr. le Gal is doing a superb impression of the
proverbial dead horse. He has circled his wagon around his
chosen but technically indefensible position of contradictory
physical acoustical claims, and he can do a far better job of
illustrating the enptiness of his "technical" position through
his own knee-jerk intractibility.
Have at it, Francois, I retire to watch the rest of the show.
François Yves Le Gal
Pinkerton) wrote:
>If (and that's a *big* IF) that is true, then they are fatally flawed,
>as previously noted. H
No demonstration, again. Try to do your homework next time and read the
papers you so pitifully try to criticize.
>You simply don't know what the heck you're talking about there,
>Francois. This is getting quite sad, really.
Yet another ad hominem attack.
>You are attemptijng to
>claim that a trombone can put out more power than is input by the
>player
I am *NOT* attempting to claim this, you and your friends do attempt to
falsify what I've written.
Please supply actual quotes and posts where I have "claimed" what you
falsely attribute to me. Put up or shut up, Mr. Pinkerton.
>"The lungs don't put out 35 w, the trombone does!"
>
>This is simply incorrect, at the most basic level.
Mr. Pinkerton, using the very same laws of thermodynamics you so much
love, let me prove that I'm right : if a trombone puts out 35 w, the
input will be more than 35 w, because no system is 100 % efficient. So
the lungs do produce *more* energy. Game, set and match.
Thank you for allowing me to demonstrate once again your near total lack
of competence in all matters scientific. And this is an ad hominem, just
like the ones you so much love.
François Yves Le Gal
Pinkerton) wrote:
>And yet, you quote it below.
I did my homework, Mr. Pinkerton, and searched for vinyl in the
references. But how could I be sure it was the paper you didn't mention
in yet another of your soggy pseudo-demonstrations?
<SNIP> the rest of Mr. Pinkerton's drivel.
François Yves Le Gal
Pinkerton) wrote:
>Fielder's figures have been cherry-picked by *you*
Oh, and you've now read and understood the papers cited as references,
Mr. Pinkerton?
<SNIP> the usual drivel.
François Yves Le Gal
Pinkerton) wrote:
>If the recording is not of a live performance, then the question of
>'fidelity' is rather moot.
Fidelity to what the artist/... intended. Is that too difficult for you
to understand this very simple concept, which is the basis of high
fidelity?
>It remains the case however
Well, you should prove first that you've *read* and *understood* the
papers you pretend to address.
<SNIP> the rest of Mr. Pinkerton's usual drivel.
François Yves Le Gal
Pierce) wrote:
>Mr. le Gal's refusal to admit to his misunderstanding of th
>fundamental prinmciples involved is achieving legendary status.
Mr. Pierce, going ad hominem, again, won't help you make your point any
clearer.
>Once can also view the directional characteristics typical of
>horn-loaded brss instruments such as the trumpet, trombone and
>french horn in figures 6.39 and 6.40 from Olson, H., Music,
>Physics and Engineering, Dover 1967
I know you love trumpets, but could you focus on the trombone, please?
What does Olson state about it's dierctional characteristics? Are they
halway between omin and cardiod? Yes. So your point is moot. Again.
>Mr. le Gal unqualified declaration:
>
> The 35 acoustics watts is coherent with a 128+ dB SPL level
> close to the trombone bell as well as with all litterature on
> the subject
It is coherent, yes. Coherent with the papers published in the Journal
of the Audio Engineering Society as well as with Mr. Atkinson's
findings. Please take the time to read the supplied references before
criticizing them directly or indirectly.
>Is in fact, in the Blackstaock quote
Which Blackstaock quote, Mr. Pierce? Care to supply it, or references
pointing to it? Does it apply to the present discussion, to trumpets or
to chopped liver?
<SNIP> the rest of Mr. Pierce post, as I can't answer arcane paragraphs
referring to a magical "Blackstaock quote" nobody has ever seen in this
thread or elsewhere.
>I retire to watch the rest of the show.
Enjoy your retirement, Mr. Pierce.
Jón Fairbairn
> On 17 Dec 2002 16:25:33 GMT, sawb...@uniserve.com (The Mad Doctor)
> wrote:
>=20
> >Let's face it, in lay terms, without hiding behind the jargon, the
> >fact is the lungs are a capable source of work and the horn is an
> >efficient way of capturing that and converting it into sonic energy.
>=20
> Let's say 5 liters of median capacity (singers, divers et al. can reach
> 8 liters), and a peak flow of up to 500 l/mn for a well trained adult.
Um, I find it hard to believe that even the best trained singer can
achieve a peak flow rate of 500l/m /and sing at the same
time/. 600l/min is unsurprising for blowing the air straight out of
one's lungs (I'm an asthmatic with chronic fatigue and I can manage
550l/min), but as soon as you try to make a sound with it the flow
rate drops markedly. Playing my French horn as loud as I could it
took some seconds to empty my lungs, which suggests real flow rates
are less than half what you quote.
A trombone is provides less resistance but even were it possible it's
hard to imagine anyone producing a 600ms blarp in a real performance.
> Hmmm, 5 liters in 600 ms, that's some energy...
Well, how much?
--=20
J=F3n Fairbairn Jon.Fa...@cl.cam.ac.u=
k
Jón Fairbairn
> <jon.fa...@cl.cam.ac.uk> wrote:
>=20
> >Unfortunately for
> >Fran=E7ois the decay time on a trombone is too short for this to mean
> >much.
>=20
> Hint: think wideband in, narrow band out.
With respect, what I put into a French horn might have a wider
bandwidth than what comes out, but it's certanly not white noise. I'd
guess that it's closer to being a square wave, but the fundamental is
the same. I can "play" a recognisable tune with my lips without the
horn, so there can't be too much energy outside the harmonics of the
note.
As others have noted, the chief effect of the horn is more efficient
coupling with the air and filtering of harmonics. Since the decay time
is of the order of a few cycles, there's no opportunity to store
energy in the resonator, add to it and have it come out later. It's
not like some Hoffnungesque instrument where the player blows into it
and no sound comes out until a valve is pressed. Given that, the peak
output power can't be more than what the lungs &c produce.
Richard D Pierce
Well, with the information Mr. le Gal supplied, it is utterly
impossible to determine. Energy is the product of force and
velocity. Specifically, 1 joule is equal to one newton meter per
second.
Mr. le Gal supplied a flow rate. That, in SI, would be in cobic
meters per second.
Mr. le Gal is telling us that newton meters per second is the
same as cubic meters per second.
François Yves Le Gal
<jon.fa...@cl.cam.ac.uk> wrote:
>Um, I find it hard to believe that even the best trained singer can
>achieve a peak flow rate of 500l/m /and sing at the same
>time/.
Sining and playing the trombone are quite different activities.
>600l/min is unsurprising for blowing the air straight out of
>one's lungs (I'm an asthmatic with chronic fatigue and I can manage
>550l/min)
I've used a very conservative value.
>Playing my French horn as loud as I could it
>took some seconds to empty my lungs, which suggests real flow rates
>are less than half what you quote.
>A trombone is provides less resistance but even were it possible it's
>hard to imagine anyone producing a 600ms blarp in a real performance.
Dunno what the actual rate would be for a trombone, which is quite a
different beast. Let's say a 1 second blast, then.
I'll leave others to calculate the actual energy.
:-)
Franco Del Principe
> On 17 Dec 2002 16:25:33 GMT, sawb...@uniserve.com (The Mad Doctor)
> wrote:
>=20
>>Let's face it, in lay terms, without hiding behind the jargon, the
>>fact is the lungs are a capable source of work and the horn is an
>>efficient way of capturing that and converting it into sonic energy.
>=20
> Let's say 5 liters of median capacity (singers, divers et al. can reach
> 8 liters), and a peak flow of up to 500 l/mn for a well trained adult.
> Hmmm, 5 liters in 600 ms, that's some energy...
Hmmm, let's see if I recall some physiology here:
A well trained young man expelling a peak air flow of 10=20
liter per second. With his diaphragma and thorax muscles he=20
can exert a pressure of say 16 cm H2O.
Converted to SI units:
air flow: 10 l/s =3D 1 x 10^-2 m3/s
pressure: 16 cm H20 =3D 1600 Pascal =3D 1.6 x 10^3 N/m2
Power =3D pressure x air flow
1 x 10^-2 m3/s x 1.6 x 10^3 N/m2 =3D 16 Nm/s
=3D 16 W !!!
If these are peak levels, this means that to blow a trombone=20
for say 10 seconds with 5 liters of lung volume produces an=20
average power of about 0.8 W.
OK, maybe Dizzie Gillespie could add some milliwatts with=20
his cheeks... :-)
Anyway, its quite amazing though, that by using the trombone=20
as a resonator so little power can produce such an SPL, of=20
course by respecting the law of energy conservation... This=20
means that the sound coming out of the bell can never exceed=20
the mentioned 16 W...
Cheers,
Franco
Simian
>
> Well, with the information Mr. le Gal supplied, it is utterly
> impossible to determine. Energy is the product of force and
> velocity. Specifically, 1 joule is equal to one newton meter per
> second.
That's watt, not joule.
Power is the product of force and velocity.
The total power will be Pressure X Area X Velocity.
Obviously area x velocity is a flow rate, (m^3/s)
A trained athlete can produce about twice the power output of a normal
healthy person, so lets extend that to trained musician. As the only
independent variable in the equation is pressure, that gives us a lung
pressure of 12kPa.
For 35W, that means that the flow rate has to be 35/12,000 = 0.003 m^3/s,
or 3 lt/s, or a lungs-full every 2 seconds.
It seems far more likely that the power output was a power/area
measurement extended to a full sphere, i.e. there was measurement of 3uW
over an area of 1 square centimeter at one meter from and directly
in front of the bell, which rapidly diminished away from that position,
but was actually taken to be the figure for the entire 12m^2 surface
area of the 1 meter sphere.
mrc...@telocity.com
> Let me begin by quoting an AES preprint by Keith O. Johnson, an AES
> Fellow, and Michael W. Pflaumer:
>
> The peak dynamic range requirement for professional recording has been
> shown to approach 130 dB [2]. Even conservative estimates produce
> numbers greater than 120 dB [3]. While the capabilities of an average
> home playback system cannot cover this range because the average home
> speaker system cannot reach the necessary peak sound pressure level
> (SPL), there will always be some systems which can. In addition, edit
> situations and listeners who change gain during a program pose added
> dynamic requirements. Therefore, these numbers remain a valid target.
> ../...
A gunshot from a medium to high power pistol or rifle heard at close
range is typically in the range of 120 to 140 dB. This can cause
permanent hearing damage and intense physical pain. It's hard to
imagine how incredibly loud this is unless you've heard it yourself...
it is clearly audible 2 miles away.
If you measure SPL right at the bell of a trumpet I have no doubt
you'll get that kind of SPL. When I played flute in the symphony I was
right in front of the trumpets (about 2-3 meters) and had to wear
earplugs. But there is no way that any person listening to acoustic
music in a live venue is ever going to hear an SPL this high unless he
crams his head inside the bell of the trumpet.
In my experience, most live acoustic music will present front row
listeners with SPLs in the 70-90 dB range. This is easily handled by
any decent home system.
François Yves Le Gal
wrote:
>But the source of the power is the person playing it.
Of course it is. Just as mains are the source of power for your system.
But what does produce sounds, the mains or the speakers?
> A trumpet doesn't even remotely resemble this
Agreed, it doesn't even resemble the trombone we are discussing.
Re. directivity, I've written quasi omni, as the actual pattern is
halfway between cardioid and omni.
>Accoustic watts do not translate to SPL except in very
>specific circumstances. (EG where the directivity of the source and the
>measuring distance are known)
Then do the maths for 128 dB SPL at 1 m with a cardioid pattern and a
zero incidence. If I do remember correctly - neither time nor desire to
do the maths now - you'll find very nearly the same figure than for an
omni.
>You seem to be in denial here in the face of insurmountable evidence to the
>contrary, why not admit a boo-boo and move on....
I'm not in denial. See supra in this post. What does produce sounds in
your system : the speakers or the mains?
Harry Lavo
news:atn1gl$kov$1...@bourbaki.localdomain...
> "Harry Lavo" <harry...@rcn.com> wrote in message
> news:atm5ih$ta$1...@bourbaki.localdomain
>
> > "Arny Krueger" <ar...@hotpop.com> wrote in message
> > news:atlob...@enews1.newsguy.com...
>
> >> Again, the basic technology, HDCD appears to have worked as
> >> claimed, and did in fact produce a technically significant
> >> dynamic range enhancement. Regrettably it was a solution looking
> >> for a problem that was not widely perceived.
>
> >> Perhaps the lesson we should draw from the HDCD experience is
> >> that it takes about 6 years for a misapplied technology to
> >> clearly fail in the audio marketplace. If that's the case, then
> >> we are two years into this process with SACD and DVD-A.
>
> > I don't recall HDCD being advertised at the top of a J&R
> > advertisement, as is SACD in the J&R advertisement in the January
> > edition of Sound & Vision magazine.
>
> That would relate to advertising, not sonic performance as perceived
> by human beings by means of just listening.
>
No, it relates to your hypothesis that SACD and DVD-A have no more staying
power than HDCD. I am only pointing out that SACD is getting growing
support, and DVD-A finally looks like it might be getting its act together.
> > I don't recall HDCD having
> > sections set up for it as have SACD and DVD-A in Tower Records,
> > Fry's, Best Buy, Circuit City, and Media Play among others.
>
> That would relate to advertising, not sonic performance as perceived
> by human beings by just listening.
>
No it relates to retailers, who are a hard bunch to convince, to lay out the
effort and inventory to add hi-rez sections to their store. Again, more
evidence of staying power.
> > The fact that you don't think there is a difference, Arny,
> > doesn't make it so.
>
> I never said it did. What I have said is that its darn hard to find
> listening tests showing that DVD-A and SACD technology provide
> advantages in sonic performance as perceived by human beings by just
> listening.
>
The opposite of my experience. My experience is that skeptics are won over
quickly - based exactly on the sound quality.
> Furthermore, the world of science has repeatedly found over a many
> decades that extending reproduction bandwidth > 15-16 KHz is
> undetectable by most or all human beings by means of just listening.
>
Unless refuted by Oohashi, which may be happening.
> There is also considerable evidence that there simply are no
> commercial recordings on CD that actually exhaust or come close to
> exhausting its dynamic range reserves.
>
Dynamic range can make itself heard as a more "black" background and more
depth of field. Those seem to be SACD attributes.
> I find it ironic that someone who claims to be a subjectivist seems
> to place so much emphasis on advertising, and so little emphasis on
> honest attempts to determine whether or not DVD-A and SACD actually
> provide advantages in sonic performance as perceived by human beings
> by just listening.
>
Advertising is essential to any format getting traction. The early signs of
it are encouraging who think that hi-rez digital is a step forward.
As for sound quality, I have proved it to myself to my own satisfaction.
That is enough for me,and for countless others..
> > There is, and the word is spreading.
>
> That's what advertising does, it spreads words. I'm more interested
> in spreading good-sounding music, which I believe is facilitated by
> finding media formats that provide advantages in sonic performance as
> perceived by human beings by the means of just listening.
>
You think those of us who are excited about SACD and DVD-A are not
interested in spreading the best sound available. What conspiracy theory
can you come up with that has us all as willing servants to SONy's corporate
interests?
On this very group, Arny, you have people in the objectivist camp who have
heard SACD and bought it. Do you think we are all hearing a mass delusion?