Cables and sound quality
John Dunlavy
I am dismayed by recent postings in this specific thread that seem to
portray the characteristic impedance and inductance of loudspeaker
cables as though they were completely independent properties.
All "real-world" wire and cables possess certain properties which
are fully treatable by well-known theory, mathematical modeling and
verifiable by precise measurements within a well-equipped lab by
competent technical personnel.
Because of what is known as "skin-effect", the resistance (and
self-inductance) of a wire (whose radius is much larger than a
skin-depth within a given frequency range) increases with increasing
frequency. A skin-depth is defined as the depth from the surface at
which the current density has dropped to 37 percent of its value at
the surface of the conductor. It results from the fact that currents
traveling along a wire penetrate to a depth (in cm) equal to 5033
times the square-root of p/uF, where p is the resistivity of the
conductor (expressed in Ohms per cm cube), F is the frequency in Hz
and u is the conductor's magnetic permeability. For a copper
conductor, this expression reduces to 6.62/sq.rt. of F. At 20 kHz a
skin-depth in copper is therefore equal to 0.0468 cm or 0.00184 inches
(corresponding to the radius of about #19 AWG wire - a quick
calculation which may be in error).
Skin-effect provides a good reason for using a large number of
individually-insulated wires for a conductor (often referred to as
"Litz wire") rather than a few wires with a radius much larger than
a skin-depth over the intended frequency range of use.
When two wires are placed parallel to each other to form a
"balanced" transmission-line (or one wire is surrounded by an outer
"shield" to form a "coaxial" transmission-line), all of their
electrical properties at frequencies from D.C. to near-light are
well-known. These are: resistance, skin-depth, capacitance,
inductance, velocity-of-propagation (VP factor) and a
"frequency-dispersive" property related to the loss-tangent of the
dielectric material (negligible with most low-loss insulating
materials at frequencies below microwave). The VP factor of a cable
is approximately proportional to the inverse of the square-root of the
dielectric-constant of the insulating material (assuming both
conductors are totally immersed within the dielectric, e.g., a coaxial
cable completely filled with dielectric material).
The "series" inductance exhibited by any cable or transmission-line
is intimately related to its characteristic impedance (and parallel
capacitance). Neglecting resistance (and any second-order effects),
the expression for the characteristic impedance (Zo) of a cable is
simply equal to the square-root of the ratio of the inductance (per
unit length) to the capacitance (per unit length). Thus, it may be
seen that the inductance and characteristic-impedance of cables are
not independent variables, as some in this newsgroup seem inclined to
imply in their postings.
If one wishes to connect the low-impedance output of a power-amp to a
loudspeaker having an average or mean impedance of 6 Ohms by means of
a cable (longer than several feet) and obtain the best possible signal
transfer, i.e., lowest waveform distortion (minimum impulse and
square-wave ringing, etc.) and the lowest mis-match loss, the answer
is simple: a high-quality cable with a characteristic impedance of 6
Ohms.
By contrast, a cable with a relatively "high series inductance",
feeding a low impedance loudspeaker, can result in a roll-off in
response at high frequencies. A "high parallel capacitance" cable
can induce oscillations to occur in many high-performance, high-slew
rate power-amps (especially those with lots of
negative-feedback). Again, the best solution is to match cable and
loudspeaker impedances - which usually optimizes series inductance.
Simple network theory clearly teaches that "reflections" of power
from a load (loudspeaker) back toward the generator (power-amp) are
minimized when the characteristic impedance of the transmission-line
is made equal to the impedance of the load (loudspeaker). And, if one
properly computes the "optimum series inductance" (and parallel
capacitance) for a cable used to connect the output of a low-impedance
power-amplifier to a loudspeaker with a "mean" or "average"
impedance of 6 Ohms (to achieve best impulse response, etc.), the
value will be found to equal that of a transmission-line with a
characteristic impedance of 6 Ohms. It is as simple as that. To imply
that the characteristic impedance does not play any role in the matter
is simply to not understand what theory has to teach.
>From a purely practical point of view, however, the question arises
as to whether either the inductance or the characteristic impedance of
a short loudspeaker cable (say less than about 15 feet) is relevant to
the production of any audible distortion (ringing, blurring, etc. on
sharp musical transients). My own feelings on the matter, backed up
by extensive lab measurements and numerous, carefully-controlled
"blind listening comparisons", are that no audible differences exist
(within a high-quality audio system) between quality #12 AWG zip cord
(with good dielectric) and some of the very expensive loudspeaker
cables being marketed (for several thousands of dollars for a 15
ft. pair).
But for those intent on covering "all bases" with respect to
insuring an optimum match between the amplifier, cable and
loudspeaker, good technical reasons exist for matching the
characteristic impedance of the cable to the mean impedance of the
loudspeaker. Anyone that denies this should either consult a book on
transmission-line/network theory or take a good undergrad course
covering the subject. And, since doing so should not add to the price
of any well-designed cable using high-quality materials, why not do so
and avoid all possible negative consequences from using a mis-matched
impedance configuration.
Why is it that there has been such an inspired pursuit of finding
fault with the one aspect of an audio system that may have the least
problems associated with it. Why not pursue and explore some of the
more meaningful and available opportunities for improving the audible
accuracy of systems, rather than worrying whether a cable has copper,
silver or "extraterrestrial flooby-dust" conductors. Or, whether the
characteristic impedance of a cable having a length under 20 feet (or
so) is 4 Ohms or 50 Ohms. Why not start worrying about whether the
"real weak-link" in the system, the loudspeaker, can accurately
reproduce a short impulse, a long rectangular-pulse (step-function),
has a good waterfall response, low harmonic and IM (Doppler)
distortion, a reasonably flat impedance curve Vs freq., etc., etc.?
Indeed, almost all loudspeakers exhibit such poor "transfer
characteristics" as to render absurd any minor distortions introduced
by a cable. If any one doubts these assertions, consult the
measurements of impulse, step and other responses shown in Stereophile
Magazine's reviews of loudspeakers - costing up to more than
$120,000/pair.
Can anyone imagine a cable with such hideous properties?
Then, there is the concern that should exist with respect to the
significant mismatch that exists between the output impedance (usually
in the range of 2 to 6 + Ohms) of tube-type power-amps and the input
impedance of loudspeakers (which frequently varies from 3 to over 15
Ohms). This mismatch in impedances can frequently cause variations in
"system frequency response" of more than plus/minus 6 dB. It can
also affect impulse response and the production of "non-linear"
distortion (which I am convinced some listeners actually enjoy).
Let's begin by establishing meaningful priorities for our concerns
and clean up the important "messes" first.
Caveat Emptor!
John Dunlavy
Fred E. Davis
Greetings, Mr. Dunlavy.
Another informative, thought-provoking post. Thanks!
I am interested in your thoughts about about the control of the
characteristic impedance of speaker cables. You mentioned some concern
about high parallel capacitance:
> A "high parallel capacitance" cable can induce oscillations to occur
> in many high-performance, high-slew rate power-amps (especially
> those with lots of negative-feedback).
Yet given realistic values for cable inductance, high values of
capacitance are necessary to maintain the low characteristic
impedance. For example, some of the lowest inductance cables I've
measured have around 0.04 uH/ft to 0.07 uH/ft (Spectra-Strip twisted
pair ribbon cable, 32 and 17 pairs of 26 AWG). These values would
require 1,111 pF/ft to 1,944 pF/ft to maintain a 6 ohm impedance.
I see two possible approaches to deal with this capacitance:
Obviously, one can design an amplifier to cope with such highly
capacitive loads. Another approach is to consider that a cable
terminated with its characteristic impedance will appear purely
resistive to the amplifier since the reactive components are balanced.
This works fine until the load is no longer simply resistive and/or
the impedance of the load no longer matches the cable. In this case,
the first approach should deal with the situation.
If one were to minimize the capacitance but maintain a low
characteristic impedance, it is necessary to have *extremely* low
inductance conductors. This is difficult to do in practice without
either dealing with increased capacitance because of conductor
geometry, or dealing with very wide, flat, thin conductors (obviously
difficult to manage). Any thoughts?
Fred
Jeff Bernhard
John Dunlavy (10236...@compuserve.com) wrote:
:
[Good stuff deleted.]
:
: >From a purely practical point of view, however, the question arises
: as to whether either the inductance or the characteristic impedance of
: a short loudspeaker cable (say less than about 15 feet) is relevant to
: the production of any audible distortion (ringing, blurring, etc. on
: sharp musical transients). My own feelings on the matter, backed up
: by extensive lab measurements and numerous, carefully-controlled
: "blind listening comparisons", are that no audible differences exist
: (within a high-quality audio system) between quality #12 AWG zip cord
: (with good dielectric) and some of the very expensive loudspeaker
: cables being marketed (for several thousands of dollars for a 15
: ft. pair).
[Good stuff deleted.]
:
: Caveat Emptor!
:
: John Dunlavy
I defer but wonder what #12 AWG zip cord has 'good' dielectric,
whatever that is defined to be. I would like to find some of this and
give it a try. I assume that most of the zip cord available has less
than 'good' dielectric. Any help?
--
Jeffrey Bernhard Harris Computer Systems Corp.
Jeff.B...@mail.hcsc.com Voice: (954) 973-5496 Fax: (954) 977-5580
*** The opinions expressed herein are mine, not those of my employer! ***
Stewart Pinkerton
je...@amber.hcsc.com (Jeff Bernhard) writes:
>I defer but wonder what #12 AWG zip cord has 'good' dielectric,
>whatever that is defined to be. I would like to find some of this and
>give it a try. I assume that most of the zip cord available has less
>than 'good' dielectric. Any help?
'Good dielectric' would be taken as non-polar, such as Teflon (PTFE),
polypropylene or polyethylene - not PVC. The very best would probably
be be foamed PTFE, otherwise known as Gore-Tex, which you'll find in
DPA cables (Black Slink etc).
Try Naim NACA 5. OK it's not quite zipcord but it's about 10-12 AWG
OFHC copper with polypropylene insulation - 'engineers zipcord' and
only about $4 a foot so it shouldn't break the bank. Good honest cable
and it's even got audiophile street cred since it's made by Naim, what
more do you want?
--
Stewart Pinkerton | If you can't measure what you're making,
A S P Consulting | how do you know when you've got it made?
(44) 1509 880112 |
C.P. Tomes
John Dunlavy wrote:
...
> Then, there is the concern that should exist with respect to the
> significant mismatch that exists between the output impedance (usually
> in the range of 2 to 6 + Ohms) of tube-type power-amps and the input
> impedance of loudspeakers (which frequently varies from 3 to over 15
> Ohms). This mismatch in impedances can frequently cause variations in
> "system frequency response" of more than plus/minus 6 dB. It can
> also affect impulse response and the production of "non-linear"
> distortion (which I am convinced some listeners actually enjoy).
>
> Let's begin by establishing meaningful priorities for our concerns
> and clean up the important "messes" first.
Thanks for unknowingly backing me up on the topic of tube amps and
"tube sound" !
I still don't understand what all the hoopla is about regarding tube
amps. Didn't Bob Carver demonstrate that a solid-state amp can be
made that exactly duplicates the "tube sound" quite a while back?
Whether this is a desirable thing to do for sound quality in the audio
system seems to be the argument.
Still hoping for that powerball win to fund the SC-IV home theater...
CP Tomes
Steve Nugent
In article <4p6tji$3...@eyrie.graphics.cornell.edu>, John Dunlavy
<10236...@compuserve.com> writes:
|> I am dismayed by recent postings in this specific thread that seem to
|> portray the characteristic impedance and inductance of loudspeaker
|> cables as though they were completely independent properties.
-clip
|> By contrast, a cable with a relatively "high series inductance",
|> feeding a low impedance loudspeaker, can result in a roll-off in
|> response at high frequencies. A "high parallel capacitance" cable
|> can induce oscillations to occur in many high-performance, high-slew
|> rate power-amps (especially those with lots of
|> negative-feedback). Again, the best solution is to match cable and
|> loudspeaker impedances - which usually optimizes series inductance.
Mr. Dunlavy,
I appreciate your most informative article, however, I would agree
with your assertion that matching cable impedance to speaker impedance
is optimal only IF the impedance of loudspeakers were purely
resistive. As we both know, loudspeaker impedances are not purely
resistive, but complex impedances resulting from the crossovers and L,
R and C of the drivers. In addition, this load is dynamic in that it
has a motor action that results in back EMF (electro-motive forces)
being generated. I believe that a good first approximation is to
match to the worst-case resistive nature of the impedance at whatever
frequency that occurs (as you have suggested), but a really optimal
solution must take into account the other factors mentioned. I
believe that some companies, such as Transparent and MIT have some
grasp of how to do this, because I have A/B'ed their cables and have
experienced the benefits first-hand.
From my experience, optimization seems to be forcing the inductance to
be as low as possible while compensating for skin-effect and then
maximizing the capacitance such that the amplifier can still
successfully drive it, without concerning onesself with trying to
match characteristic impedance of the loudspeaker.
Steve N.
Randall Bradley
No, Bob Carver did not demonstrate that a solid state amp can sound
like a tube amp. What he demonstrated is that an ad campaign can
convince unknowing "consumers" to buy his product.
_-_-randy_-_
BEAR Labs
ra...@rdrc.rpi.edu
"...the BEAR nose..."
Gene Steinberg
In article <4pcau9$3...@eyrie.graphics.cornell.edu>,
ra...@pulsar2.rdrc.rpi.edu (Randall Bradley) wrote:
>No, Bob Carver did not demonstrate that a solid state amp can sound
>like a tube amp. What he demonstrated is that an ad campaign can
>convince unknowing "consumers" to buy his product.
Do you honestly think there something magical and mystical about a
"tube" sound that cannot be duplicated in a solid state amplifier by a
few circuit modifications (primarily increasing the output impedance
to one ohm or greater)?
--
Peace,
Gene
hen...@nortel.ca
Steve Nugent (nug...@ssd.intel.com) wrote:
: As we both know, loudspeaker impedances are not purely resistive, but
: complex impedances resulting from the crossovers and L, R and C of
: the drivers. In addition, this load is dynamic in that it has a motor
: action that results in back EMF (electro-motive forces) being generated.
These two statements say exactly the same thing. The effect of
"back EMF" on the load looking into the speaker terminals (i.e., from
the electrical impedance point of view) is exactly the same as if
there was no loudspeaker driver at all and an equivalent network of
resistors, capacitors, and inductors was installed in its place. The
energy storage and dissipative effects of the electromechanical system
formed by the loudspeaker driver are entirely analgous to the same
effects in networks of complex impedances. There is no point in
distinguishing the effect of "back EMF" from that of any other
reactive components (such as the crossover) in the system. There most
definitely is no special interaction between the speaker driver and
the feedback loop in the amplifier that somehow increases the damping
of the driver beyond that which would be achieved using an ideal
voltage source (without feedback) to drive the speaker, as is
sometimes claimed in audiophile advertisements and articles.
-Henry
--
ATTENTION! Reply to h...@nortel.ca (hen...@nortel.ca won't work).
--
Mandatory grammar note: "Lose" (as opposed to find); "Loose" (opposite of
tight); "Its" (possessive form of "It"); "It's" (contraction for "It is")
Thx1901
I'll stay out of the cable mess as I don't have the engineering skills
to back up what I hear though I do think my cardas cable (hexlink gold
5c) is markedly better than zip cord in my system. Mre bass, more
transient response etc.
But as to Bob Carver proving that his solid state amps could sound
like tubes it would be wise to read the actual test results in
Stereophile and the ensuing legal suit brought by Bob Carver against
Stereophile, before taking Carvers advertising as truth.
As I recall the after many days of trying bob could never make his amp
sound the same as the Marantz 9's ( I think that was the tube
reference) and then after stereophile published the article ( a Cover
story) Carver sued in the settlement both were enjoined from talking
about the other, hence the lack of advertising of Carvers amps and the
lack of reviews for a few years.
Long time ago, but still further proof that what people claim in there
advertising and there white papers is not always reality no matter how
well the theory matches the current understanding of physics. If you
can't measure it doesn't mean its not there it just means you can't
measure it yet.
I just don't know.
uh.......OH!
>I still don't understand what all the hoopla is about regarding tube
>amps. Didn't Bob Carver demonstrate that a solid-state amp can be
>made that exactly duplicates the "tube sound" quite a while back?
>Whether this is a desirable thing to do for sound quality in the audio
>system seems to be the argument.
>
>Still hoping for that powerball win to fund the SC-IV home theater...
Whoa! Wait one grainy bass dropped out and the midrange tastes like
paste minute. What tube amps were you comparing to a Bob Carver
design, besides his tube amps, which admittedly I haven't heard but
would like to ingnore for this post? The first power amp I ever
bought, at a "superstore" no less, was a Carver TFM-25. I assumed
that it sounded like a tube because the explanation in the back of the
manual said it did. Then I heard a good solid-state amp. I thought,
wow, tubes must suck, or this amp must sound more like tubes. Then I
heard a tube amp. Regardless of preference, Carver amplifiers sound
nothing like any tube amplifier _I've_ heard. Not saying that the
sonic characteristics can't be duplicated, just that I've never heard
it done. Spectral DMA-180 was close, but with solid-state
heel-clicking precision. Still not the same. Was that a very subtle
joke?
colin
"I don't know anything."
Stewart Pinkerton
Ge...@worldnet.att.net (Gene Steinberg) writes:
Well yes. Hollow state amplifiers exhibit microphony, graceful
overload behaviour and limitations due to the need for an output
transformer. These factors cannot readily be duplicated by 'a few
circuit modifications' to a solid-state amp.
Gene Steinberg
In article <4pfdj9$6...@eyrie.graphics.cornell.edu>, co...@iofr.com
(uh.......OH!) wrote:
>Whoa! Wait one grainy bass dropped out and the midrange tastes like
>paste minute. What tube amps were you comparing to a Bob Carver
>design, besides his tube amps, which admittedly I haven't heard but
>would like to ingnore for this post? The first power amp I ever
>bought, at a "superstore" no less, was a Carver TFM-25. I assumed
>that it sounded like a tube because the explanation in the back of the
>manual said it did. Then I heard a good solid-state amp. I thought,
>wow, tubes must suck, or this amp must sound more like tubes. Then I
>heard a tube amp. Regardless of preference, Carver amplifiers sound
>nothing like any tube amplifier _I've_ heard. Not saying that the
>sonic characteristics can't be duplicated, just that I've never heard
>it done. Spectral DMA-180 was close, but with solid-state
>heel-clicking precision. Still not the same. Was that a very subtle
>joke?
That particular amplifier was supposedly based on the sonic signature
of Carver's own Silver Seven. However, to do a fair comparison, you'd
have to do a double blind test of both.
--
Peace,
Gene
Gene Steinberg
In article <4pfd24$6...@eyrie.graphics.cornell.edu>, thx...@aol.com
(Thx1901) wrote:
>But as to Bob Carver proving that his solid state amps could sound
>like tubes it would be wise to read the actual test results in
>Stereophile and the ensuing legal suit brought by Bob Carver against
>Stereophile, before taking Carvers advertising as truth.
The ensuing legal action was triggered by Stereophile when Carver ran
a long ad quoting one of that magazine's unfavorable reviews of their
amps, and comparing it to favorable reviews of the same amp in other
magazines. An out-of-court settlement resulted in Stereophile
agreeing not to mention Carver in their editorial pages for a period
of time.
--
Peace,
Gene
Lon Stowell
In article <4pg7q3$a...@biosun.harvard.edu> a...@borealis.com writes:
>
>Well yes. Hollow state amplifiers exhibit microphony, graceful
>overload behaviour and limitations due to the need for an output
>transformer. These factors cannot readily be duplicated by 'a few
>circuit modifications' to a solid-state amp.
Isn't the typical circuit noise floor of a tube amp more rolled
off in the high end, whilst traditional transistor amps have noise
which is fairly constant all the way into the upper freq's?
Bob Myers
Steve Nugent (nug...@ssd.intel.com) wrote:
> From my experience, optimization seems to be forcing the inductance to
> be as low as possible while compensating for skin-effect and then
> maximizing the capacitance such that the amplifier can still
> successfully drive it, without concerning onesself with trying to
> match characteristic impedance of the loudspeaker.
You lost me; I can see where minimum inductance might be a benefit,
assuming a perceivable problem in the first place, but why would one
want to MAXIMIZE the cable capacitance?
Bob Myers KC0EW Hewlett-Packard Co. |Opinions expressed here are not
Workstations Systems Div.|those of my employer or any other
my...@fc.hp.com Fort Collins, Colorado |sentient life-form on this planet.
Stewart Pinkerton
lsto...@pyramid.com (Lon Stowell) writes:
> Isn't the typical circuit noise floor of a tube amp more rolled
> off in the high end, whilst traditional transistor amps have noise
> which is fairly constant all the way into the upper freq's?
Not if the tube amp doesn't have an output transformer! Which tube
preamps tend not to.
Steve Nugent
|> There is no point in distinguishing the effect of "back EMF" from
|> that of any other reactive components (such as the crossover) in
|> the system. There most definitely is no special interaction
|> between the speaker driver and the feedback loop in the amplifier
|> that somehow increases the damping of the driver beyond that which
|> would be achieved using an ideal voltage source (without feedback)
|> to drive the speaker, as is sometimes claimed in audiophile
|> advertisements and articles.
So what you are saying here is that even though the speaker voice-coil
inductor is being mechanically forced to move through what might not
be a completely uniform magnetic field, it behaves substantially like
a simple inductor?
Steve N.
Richard D Pierce
In article <4pkj3s$l...@eyrie.graphics.cornell.edu>, Steve Nugent
<nug...@ssd.intel.com> wrote:
No, he's not saying that. The electro-mechanical behavior of the
woofer that causes the the impedance to vary according to frequency
the way it does presents an electrical load that is identical to a
fairly simple equivalent circuit made up of ordinary resistors,
capacitors and inductors. The motional impedance, as seen
electrically, is equivalent to nothing more than a simple parallel
R-L-C resonant tank circuit. The enclosure can be similarily replaced
with another network (in the case of a vented enclosure, it looks like
a series R-L-C resonant leg).
In fact, using a dozen or so parts, one can build a passive electrical
network that looks indistiguishable from a speaker to the
amplifier. Make it more complex, and you can simulate amplitude
non-linearities very nicely.
Such equivalent behavior, it turns out, is the foundation to the
modern understanding of how drivers, enclosures and whole speaker
system work, electrical input to acoustical output.
--
| Dick Pierce |
| Loudspeaker and Software Consulting |
| 17 Sartelle Street Pepperell, MA 01463 |
| (508) 433-9183 (Voice and FAX) |
Rick Becker
Waltzing at the Waldorf (Part IV)
Still on the 9th floor, In the Mesa room I had my first sight and
sound of the Gallo speakers. The Gallos had the Bassballs and were
powered by twin Mesa Baron tube amps. The sound here was not as
glorious as all the hype in this newsgroup had led me to expect. Not
bad, but there were no harp carrying angels flying about the room.
The Aussies showed with Music Labs amplifiers driving Ambience
speakers--king of a Martin Logan type planar. The Music Labs
(actually, they use lower case in their name, so it is "music labs"
ala conrad johnson, and they are hand made in another lower case
company "audio labs of melbourne". The ML815 MkII is 100 wpc and the
ML825 MkII is 250 wpc. These bad boys operate in Class A and feature
balanced and unbalanced inputs. These amps very tastfully designed,
and I find myself returning to their brochure time and again. (A
price list would probably cure me of this behavior). The sound in
this room was very nice.
It was interesting to hear a little 30 wpc Quicksilver amp drive
a Model 10 Linaeum speaker. The speaker went nice and low, but the
Quicksilver didn't have the power to make it really boogie. Just a
simple mis-match--check out both speaker and amp if you get the
chance.
Now down to the 8th Floor:
At the Eiger AC-3 home theater demonstration I squeezed into the
room and stood at the back wall, just as I had done at Montreal. The
speakers were aluminum with a dense plastic-like material sandwiched
between two thin layers of aluminum with a faux-marble finish. They
weighed only 40 lbs each. Nicely finished, they were good speakers,
but at $10,000/pair they have alot of competition. As for the AC-3,
the surround effect was no where near as good as I heard in Montreal,
even at the back of the room. In fact, I in Montreal I heard an
entire AC-3 system costing less that a pair of Eiger speakers that
totally blew me away. I suspect that for movies, upper-mid to
lower-high-end will be the optimal level for AC-3. Neither was the
Eiger demonstration overwhelming on a music-only basis. Maybe the
people up front or in the center of the room had a better experience
than I did, but I didn't sense that kind of enthusiasm in the crowd.
Dynaudio gave show-goers an unusual treat. The excellent sound
in this room came from a pair of Dynaudio Statement speakers that were
13 years old! A floor standing model with the woofer on top and the
drivers getting progressively smaller as they approached the floor. I
want to say the rims of the speaker were polished brass, but then
someone would have to probably correct me. Gold? These were
outrageously expensive, as were their Arbiter amplifiers at $75-85,000
each. (They were monoblocks). Levinson gear front-ended the system.
In another Dynaudio room I got to hear the Contour 1.3 speakers with
some real world electronics. This system sounded pretty decent, too,
but for $2000, I would certainly so some serious comparison shopping.
As many others have noted, there was very nice music coming from
the JVC CD mastering room where Levinson gear was driving Wilson
Watt/Puppies. XRCD unenhanced (?) recording mastering process.
Nice sound came from the Probe speakers with an upper/lower
module configuration with rear-firing tweeter in the upper module and
8" woofer in the bass module, powered by Aragon electronics and a
Theta Data transport.
The Lamm Audio room had superb sound with Lamm tube amplifiers at
$18,000 each, 90 watts/channel, single-ended triode, Class A, driving
Ars Acoustica speakers--kind of a Watt/Puppy set-up, only taller-about
the size of the Wilson Witts, in gloss black lacquer. Ars is a new
Canadian company and this was their debut, which is why I did not see
them in Montreal a few months back.
The Ayre pre-amp ($5000) is now on the market with a ($6000)
phono stage. (Or was that a pre-amp with phono stage for $6000)? At
the end of the year they will be coming out with a line stage for
$3000. The $5000 pre-amp was a nice looking unit.
Good sound coming from Proac 2.5 speakers driven by Cary 805
monoblocks. And then in the next room Cary 805s were driving
Vandersteen Model 5s--a decent sound, but not spectacular.
Not specatular sound also came from silver colored Symphonic Line
speakers.
In the Hales room I heard the Concept 2 speaker driven by a 45
wpc Sonic Frontiers Anthem line tube amp. The room was not treated
very well and the sound was a little veiled, but decent for the price.
At Sonic Frontiers I learned that the linestage Line 1 and Line 2
will be out in September. These have the neat little round remote
control. The Line 2 has a separate power supply and the reported
noise floor of these line stages is -130db. The Line 1 will be $2000.
Music in the Sonic Frontiers room came from their tube CD player
($3500) into their Power 3 amps to the Hales Concept 5 speakers. The
room had minimal treatment and the sound was excellent. Chris Johnson
was the host here and he is quite a gentleman, tactfully balancing
inquiry with playback in a room that seemed to draw a lot of interest
on the several occasions I stopped in.
That's it for tonight. I hope this makes it to the moderators.
Rick Becker
Rochester, NY
hen...@nortel.ca
Steve Nugent (nug...@ssd.intel.com) wrote:
: |> There is no point in distinguishing the effect of "back EMF" from
: |> that of any other reactive components (such as the crossover) in
: |> the system. There most definitely is no special interaction
: |> between the speaker driver and the feedback loop in the amplifier
: |> that somehow increases the damping of the driver...
: So what you are saying here is that even though the speaker voice-coil
: inductor is being mechanically forced to move through what might not
: be a completely uniform magnetic field, it behaves substantially like
: a simple inductor?
I am saying that the electromechanical system composed of the
voice coil and associated mass, the cone surround and spider, and
the magnet can be modeled as a set of energy storing and dissipative
elements. Contrasted to a purely electrical or purely mechanical
system, there is a continuous interplay between electrical and
mechanical energy in the loudspeaker driver. But this is irrelevant
from the point of view of a device connected to the speaker terminals.
To an external device (e.g., an amplifier), the driver looks like a
network of resistors, inductors, and capacitors having perfectly
ordinary impedance characteristics. Because the driver does not
generate more energy than it consumes, its driving point impedance
obeys the constraints of passive networks. "Back EMF" is simply
the mechanism by which this particular electromechanical system
happens to acquire its electrical characteristics.
Let me put it another way. If you put a battery across a coil,
some energy will be stored in the resulting magnetic field. If you
remove the battery, the field will collapse and some of that energy
will be released, causing a spark. If you put a battery across the
terminals of a speaker, some energy will be stored in the mechanical
displacement of the voice coil. When the battery is removed, the
energy will be released. There is a set of electromechanical
analogs that allows you to represent the circuit behavior of the
driver as pure R's, L's, and C's. There is no need to perform the
tedious (to an electrical engineer) electromagnetic and mechanical
calculations to predict the terminal impedance characteristics once
the electrical analog has been defined. Nor do we need a special
component, the "back EMF generator", to develop this model.
Now, you bring up another issue entirely when you talk about
the (possibly) non-uniform magnetic behavior in the gap. There
are many potential nonlinear elements in a loudspeaker driver.
If the driver is designed well, it will behave in a substantially
linear way when the excursion is not too large. In that case, the
electrical analog and the resulting terminal impedance will consist
of linear resistors, inductors, and capacitors. If you want to
model the large-signal behavior of the driver, or examine the
nonlinearities with precision, you need a nonlinear model. But
the nonlinearity can be accommodated in the electrical domain
by introducing nonlinear R's, L's, and C's, although the analysis
becomes much more difficult. But the original point remains
unchanged.
I don't know to what extent you may or may not understand what
I am trying to say, but I do know this made-up distinction between
loudspeaker loads and electrical networks in general causes a lot
of confusion for many audiophiles and audiophile journalists. I
often see remarks about how the "back EMF" from the speaker
interacts with the feedback loop in the amplifier, and therefore
there is some kind of delay between the time the amp signals what
it wants the speaker to do and the return of a message from the
speaker (via "back EMF") as to what actually happened. And then
there is another delay as the amplifier computes some correction
factor based on how the speaker should have moved compared to how
it really moved and sends this new message back to the speaker.
And so on ad infinitum. The result is an unending spiral of missed,
delayed, and misinterpreted messages passing back and forth between
the amp and speaker. It's really terribly awful and messes up the
poor audiophile's sound horrifically.
Now, if only the speaker cone were massless, or the amplifier
had no negative feedback, this entire oscillating miasma of time-
smeared electrical energy would be nipped in the bud, so to speak,
and considerable trauma to the audiophile "Brain Nerve" would be
wholly avoided. It is for this reason that single-ended triodes
and horn loudspeakers are infinitely better than any other source
of sound reproduction on the planet.
It's all very appealing and all very wrong (or at least terribly
distorted), but the topic makes for interesting lecturing by arrogant
and impatient engineers like me, who, in truth, are out to destroy
any and all pleasure the audiophile hobby may give by sucking the
color out of musical interpretation and enjoyment and substituting
a uniformly grating lattice of black and white digital bits.
What really goes on is that the amplifier (feedback or none)
behaves as an active network with some complex transfer function
and output impedance, and the driver appears as a passive network
with some complex input impedance. The voltage developed across
the loudspeaker terminals in response to some input to the amplifier
can be predicted with a high degree of accuracy given a reasonable
model (that is not beyond the ability of an electrical engineering
graduate student to compute) and, having satisfactorily solved the
problem, everyone involved immediately goes to the local Italian
restaurant for many rounds of pizza and beer. Audiophiles are
left behind beating their heads against the wall and trying in
vain to dampen the ringing in their ears by the application of
Shakti stones, mpingo disks, and Harmonix tuning dots. If they
have any sense, they just take some Advil and lie down on one of
Michael Green's pillows for a long, long sleep.
If course, you're perfectly entitled to disagree with the
technical points I have just made, and I encourage you to write at
length about it so that you might catch Dick Pierce's attention.
Then we might have a good laugh and learn even more about this
interesting subject. Or don't. It's up to you.
Does that clear the whole topic up?
ri...@av.psychiatry.rochester.edu
Pete...@ix.netcom.com
Rick Becker <ri...@av.psychiatry.rochester.edu> wrote:
> Waltzing at the Waldorf (Part IV)
> Still on the 9th floor, In the Mesa room I had my first sight and
>sound of the Gallo speakers. The Gallos had the Bassballs and were
>powered by twin Mesa Baron tube amps. The sound here was not as
>glorious as all the hype in this newsgroup had led me to expect. Not
>bad, but there were no harp carrying angels flying about the room.
Ummmmmm Rick.....
those were NOT the Gallos......not even close........me thinks those
were the Cabosse (spelling?) prototypes.........
The Gallos were on the 6th floor and were hooked to a pair of Pass
mono blocks..........and they souded great. The mesa boogie room did
not....you were correct on that point.
this is how misinformation is spread...and nasty rumors are started.
you are a very bad boy.... :)
Richard D Pierce
In article <4plcgq$s...@biosun.harvard.edu>, <h...@bnr.ca> wrote:
>Steve Nugent (nug...@ssd.intel.com) wrote:
>
>: |> There is no point in distinguishing the effect of "back EMF" from
>: |> that of any other reactive components (such as the crossover) in
>: |> the system. There most definitely is no special interaction
>: |> between the speaker driver and the feedback loop in the amplifier
>: |> that somehow increases the damping of the driver...
>
>: So what you are saying here is that even though the speaker voice-coil
>: inductor is being mechanically forced to move through what might not
>: be a completely uniform magnetic field, it behaves substantially like
>: a simple inductor?
>
> I am saying that the electromechanical system composed of the
>voice coil and associated mass, the cone surround and spider, and
>the magnet can be modeled as a set of energy storing and dissipative
>elements. Contrasted to a purely electrical or purely mechanical
>system, there is a continuous interplay between electrical and
>mechanical energy in the loudspeaker driver. But this is irrelevant
>from the point of view of a device connected to the speaker terminals.
[huge deletia]
Henry, this was a generally excellent post, one that dealt with the
relevant issues in a coherent, straightforward fashion.
I'd like to take the discussion one step further and point out a
generalization of the principles invloved. That generalization is the
concept of resonance and how energy moves back and forth in resonant
systems.
There is an utterly false concepts that is bandied back and forth by the
hi-fi press (who may or may not know any better: it's still wrong,
though) and by some manufacturers and dealers (who, frankly, deserve to
be the first lined up against the wall and shot). This concept is the one
of "energy storage." It's as if the speaker or the cable or whatever gets
some energy, secretly squirrels it away, and then, only after some
waiting period, releases it back into the system. In a word, this is
complete hogwash.
Whether it be at the fundamental resonance of a loudspeaker system, the
undamped ringing of a breakup mode of a cone, the interaction of cables
inductance and capacitance, whatever, the important thing to remember is
NOT that energy is being stored, but that energy is being exchanged back
and forth on a periodic basis: the system is resonating.
"Back EMF,", that ol' demon that many claim is such an evil culprit, is
not a phenomenon in and of itself: it is a symptom of an underlying
property of the system. The system is resonating. And it makes not one
wit to the amplifier whether that resonance is due to a combination of
two opposite electrical reactances or two opposite mechanical reactances,
the effect is IDENTICAL.
WHat is a resonance? It's actual quite simple. A resonance occurs when
you have two opposite "reactances" (a reactance is simply a mechanical or
electrical element that "reacts", it, in effect "pushes back") that can
and do exchange energy back and forth between them. In the process, the
type of energy at play is transformed.
Let's look at a mechanicallyresonance. This requires that we have two
opposite reactances, specifically a mass and a stiffness or compliance.
Without both, it is impossible to have a resonance. Imaging, for example,
a weight suspended on a spring (gee, like a turntable on its suspension
or a loudspeaker cone working agains the air in the box). If we do
nothing to the system, nothing happens. But now, add some enrgy to the
system: pull the weight down, BUT DON'T LET GO YET. At that moment, you
have added energy to the system in the form of POTENTIAL energy, enrgy do
to the extension of the spring: you had to work against the stiffness of
the spring using energy. Let the weight go. The potential energy stored
because the spring is stretched imediately begins to cause the spring to
contract. At exactly the same time, the weight, because the spring is
contracting, starts to accelerate towards the rest position of the
system.
What's happening? The potential energy due to the stretching of the
spring is being continuously converted into kinetic energy due to the
movement of the mass.
Now, when the mass reaches rest position of the system, the spring is no
longer stretched, so NO energy is stored in that spring. But the mass is
moving, in fact, it's moving as fast as it can. ALL of the enrgy you
orginally put in that spring by stretching has now been transferred to
the mass.
Now what? Well, that mass is moving, and it's now going to start
compressing the spring. The kinetic energy of the moving mass starts
compressing the spring, the spring, in turn, reacts by pushing more and
more as it gets compressed until all of the kinetic enrgy originally in
the moving mass has compressed the spring as far is it can go, and now
all the energy is now tied up in the potential energy of the compressed
spring. The mass is no longer moving, and there's no kinietic energy in
the system.
Now, the spring wants to uncompress itself. It starts pushing on the
mass, which starts accelerating back in the oppsite direction tworards
the rest position. The potential energy is being converted back into
kinietic energy.
And so on and so forth the cycle proceeds, back and forth, energy being
converted between its potential and kinetic form at a rate determined
SOLELY by the stiffness of the spring and the mass of the, well, mass.
And the same interplay is working whether, as we said, it's a mass on a
spring, a turntable on a suspension, a stylus on the end of a tonearm,
the stylus on the flexible vinyl in the groove, or the string on a
violin, for that matter. Precisely the same interaction is taking place.
Instead, lets connect a capacitor and an inductor together. Put an
electrical charge in the capacitor. At that instant, you've added energy
to the system in the form of potential ennergy that shows up as voltage
across the capacitor, the energy is sctually stored in the electrical
field in the capacitor. Now, connect the inductor to the system. What
happens?
Well, the presence of the potential energy inthe form of a voltage that's
now simpressed across the inductor causes current to start flowwing
through the inductor. That current generates a magnetic field, and
slowly, just like in our spring and weight experiment, more and more of
the energy originally stored as potential energy in the capacitor is
stored as kinetic energy in the inductor's magnetic field. Eventually,
all the enrgy gets so converted. But now, that current starts charging
the capacitor, and the kinetic energy in the inductor is converted to
potential energy in the capacitor again.
And just like our weight and spring experiment, the potential energy in
the voltage across the capacitor is converted to kinietic energy of
current through the inductor and back again at a rate SOLELY determined
by the size of the capacitance and inductance.
The equation for determining the rate at which the energy interchange
occurs in our mechanically resonant system is thus:
1
F = -------------
2 pi sqrt(M*C)
where F is the resonant frequency in Hz (cycles per second), M is the
mass in kilograms, and C is the compliance in Newtons/meter.
The equation for determining the rate at which energy interchange occurs
in our electrically resonant system is thus:
1
F = -------------
2 pi sqrt(L*C)
where F is the resonant frequency in Hertz, L is the inductance in
Henries, and C is the capacitance in Farads.
The two, you would agree, look remarkably the same. For a good reason:
THEY DESCRIBE PRECISELY THE SAME PHENOMENON.
There is no magic involved here, the underlying principle is simple, yet
very profound. There is no element magically and secretly stealing
energy, waiting till no one is looking, and then when the system is least
able to deal with it, suddenly releases it without warning.
The predictive powers of this models is very powerful. It completely
explains a whole range of observable phenomenon to the level of whetever
precision we are able to bring to bear on the problem.
These other "theories" however, fail grossly at predicting observable
reality. Feedback loops DO NOT interact with "back EMF" the way some in
the press and manufactory say they do: the phenomenon that their
"theories" predict simply do not occur. The notion of spikes and cones
and other such trickery "sink" energy is completely contradicted both by
real theory AND observations.
There is no magic, there are no "radical" theories. What we, regrettably
have, is handwaving and smoke and mirrors and random guesses and poorly
informed "theories" by people who either don't know any better or who do
know better and lieing. In both categories are those who succeed in
lining their pockets.
Steve Nugent
In article <4pjtcp$e...@eyrie.graphics.cornell.edu>,
my...@hpfcla.fc.hp.com (Bob Myers) writes:
|> Steve Nugent (nug...@ssd.intel.com) wrote:
|> > From my experience, optimization seems to be forcing the
|> > inductance to be as low as possible while compensating for
|> > skin-effect and then maximizing the capacitance such that the
|> > amplifier can still successfully drive it, without concerning
|> > onesself with trying to match characteristic impedance of the
|> > loudspeaker.
|> You lost me; I can see where minimum inductance might be a benefit,
|> assuming a perceivable problem in the first place, but why would
|> one want to MAXIMIZE the cable capacitance?
I was not implying that this happens intentionally. Only that it is a
result of trying to minimize the inductance. A clearer statement
would have been "allowing the capacitance per unit length to increase
to a reasonable maximum value (as a result of the cable geometry) that
an amplifier can be expected to drive and remain stable". There are
obviously issues with this strategy if the cable length is variable.
I almost never get it right on the first try.
Steve N.
"never too old to learn"
Rndmtn
Hmmmmm, more people harping on cables.
So what's new.
I'm sorry guys, especially Gene. I did do a sighted test and compared
cables and I saw a difference: on a spectrum analyzer. One showed one
speaker cable was able to hit 25 hz versus another which barfed out at
35. Sorry. Differences do exist and it seems that regardless of the
existence of double blind followers: some numbers don't lie either.
What I find important is that the spectrum analyzer (my friends and
very pricey) did see a difference between cables. So, there can be a
correlation to more bass versus another. And no, you can't say I was
biased by a subjective placebo effect. Numbers are numbers.
In my case, Audioquest does not go as low as Kimber. It did not
extend as high either. 8TC is better in terms of frequency range in
my system (remember my system) than Audioquest. No buts about it. 25
beats out 35 any day. I don't think the numbers have changed
recently.
This only reinforces my impression of the KimberKable as more balanced
than the Audioquest, in my case. The tonal balance was indeed better
and a reason exists.
So double blind testing is not the end all of justifications. Oh, I
measured the frequencies on the specturm analyzer at my listening
position, not next to the speakers etc. 10hz of differences seems to
imply to me that there must be a difference between cables. I don't
give an SH if you say no. Sometimes the numbers do reinforce the
impressions.
Don't develop ulcers over this issue. It really doesn't matter in the
context of whether or not HDCD is better than SBM recordings to me. I
have more of a cow with producers who juice up the treble to really
painful levels on some commercial CDs. But then, someone may tell me,
it is an illusion. It really sounds cool. Bah.
Get over it, as Don Henley would say.
d maruyama
hen...@nortel.ca
I seem to be bubbling with energy to write long articles lately.
Oh well.
I got an email question about damping in response to my last
posting on this thread. I thought my response would be worth posting.
Here it is:
-Henry
-----
About damping, many people assume that "perfect" damping means
"infinite" damping, which is to say, the speaker cone has no motion of
its own, but only responds to the signal provided by the amplifier.
If you think about this, it can't possibly be. If a battery is placed
across the speaker terminals, the cone will be displaced. When the
battery is removed, the cone snaps back to the resting point. The
function of displacement versus time as the cone returns to rest is
determined solely by the restoring force, mass, and damping on the
cone and not by the applied voltage. If instead of open-circuiting
the terminals, the terminals are shorted, the electrical damping is
increased, slowing down the cone motion. But even with a perfect zero
resistance across the terminals, the cone still moves on its own.
If you have infinite damping, the cone doesn't move at all, because
the potential energy due to the cone displacement is absorbed as soon
as it is released and never gets a chance to express itself as kinetic
energy of motion.
You might think the best solution is a cone of zero mass, so that
the snap-back occurs with infinite speed. The problem here is that
the speaker will then have non-flat frequency response. The reason is
that the acoustic radiation resistance (air loading) increases with
increasing frequency up to the point where the wavelength of sound is
smaller than the cone diameter (at which point the cone starts to
"beam"). To obtain flat response, the driver is operated in its "mass
controlled" frequency band, where the cone displacement decreases
naturally with frequency and exactly compensates the increase in
acoustic coupling.
We could envision other ways of solving this problem, but then we
would be taking about different kinds of speakers than direct-loaded
dynamic drivers.
The bottom line is this. For flat frequency and phase response in
band, the ideal situation is not zero cone mass or infinite damping.
The proper damping, which is a system parameter taking into account
the driver, crossover, cable, and amplifier character- istics, is the
one that gives flat response and smooth low-frequency rolloff. It
corresponds to a damping factor of about 0.7 in a sealed box system,
which is rather far from infinity!
Therefore, the amplifier doesn't really "control" the speaker cone
at all, at least as envisioned by most audiophiles. To really
understand what's going on, you need to look at the "forced" and
"natural" responses of the loudspeaker system, functions that have
precise engineering definitions and which describe entirely the
behavior of the speaker (at this fairly general, but reasonably
precise level of abstraction).
Stewart Pinkerton
rnd...@aol.com (Rndmtn) writes:
>I'm sorry guys, especially Gene. I did do a sighted test and compared
>cables and I saw a difference: on a spectrum analyzer. One showed one
>speaker cable was able to hit 25 hz versus another which barfed out at
>35. Sorry. Differences do exist and it seems that regardless of the
>existence of double blind followers: some numbers don't lie either.
What numbers? In the first place it seems pretty unlikely that there
would be a big difference in bass response between 8TC and the
unspecified Audioquest cable. In the second, you quote two numbers and
a 'hit/barf' in support of your argument. This is an unconventional
notation with which I am not familiar. Perhaps you could enlighten us
with a little more detail on your actual test procedure, equipment
used and results gained. You know, numbers.
>What I find important is that the spectrum analyzer (my friends and
>very pricey) did see a difference between cables. So, there can be a
>correlation to more bass versus another. And no, you can't say I was
>biased by a subjective placebo effect. Numbers are numbers.
Fine, great, inquiring minds want to know. What numbers?
>In my case, Audioquest does not go as low as Kimber. It did not
>extend as high either. 8TC is better in terms of frequency range in
>my system (remember my system) than Audioquest. No buts about it. 25
>beats out 35 any day. I don't think the numbers have changed
>recently.
Fine, great, but what do you mean by that? One is -3dB at 35Hz and the
other at 25Hz? Major revelation if so - give us more detail.
>This only reinforces my impression of the KimberKable as more balanced
>than the Audioquest, in my case. The tonal balance was indeed better
>and a reason exists.
>So double blind testing is not the end all of justifications. Oh, I
>measured the frequencies on the specturm analyzer at my listening
>position, not next to the speakers etc. 10hz of differences seems to
>imply to me that there must be a difference between cables. I don't
>give an SH if you say no. Sometimes the numbers do reinforce the
>impressions.
This is an acoustic spectrum analyser? What make & model? How stable
was the microphone position? Did you move the speakers when changing
cables? Did you place yourself in exactly the same position when
measuring, to account for reflections from your body? More detail,
more detail.
Chuck Ross
> But as to Bob Carver proving that his solid state amps could sound
> like tubes it would be wise to read the actual test results in
> Stereophile and the ensuing legal suit brought by Bob Carver against
> Stereophile, before taking Carvers advertising as truth.
>
(-SNIP-)
> As I recall the after many days of trying bob could never make his amp
> sound the same as the Marantz 9's ( I think that was the tube
> reference) and then after stereophile published the article ( a Cover
> story) Carver sued in the settlement both were enjoined from talking
> about the other, hence the lack of advertising of Carvers amps and the
> lack of reviews for a few years.
There were actually two separate incidents with the Carver Challenge;
one of them occurring several years before the big hoopla. The amps, I
recall, were not Marantz 9's, but NYAL tube amps, described in the
first published review, but curiously, the name of the "reference"
amps went undisclosed in the follow-up review.
In fact, as I recall it, the actual solid-state amp that Bob Carver
used with the "t-mod" was _not_ the same amp named in the follow-up
review. I had a white paper distributed by Carver in which the whole
situation was made even more distorted by comparing his original amp's
t-mod with yet another tube amp.
At any rate, in the first published article, Carver's amp, then a
prototype, was compared with the "reference" tube amp, and no-one on
the listening panel was able to tell the difference between one amp
and the other in some extensive listening sessions.
The second article concerned with whether or not Carver's "production"
version would sound the same as the prototype did not go so easy on
Carver. None of the listening panel could tell the difference between
the production version and the "reference" tube amp except Gordon
Holt, who was able to id the prototype about 6 out of 10 times.
However, Carver complained, and rightly so, to my way of thinking,
that the "reference" amp had aged considerably in the several years
since the original test; still had the same tubes, but no longer was
able to produced a deep null in a "null test" and no longer
represented the first "reference" amp.
Stereophile seemed not to pay the slightest attention to this, and
Carver was really pissed and ran a string of ads in 'Sphile
complaining about his mistreatment and the dishonesty of the second
review.
Stereophile was upset about this and there was a court battle which
blocked Carver's advertising in the magazine, and also kept the
magazine away from Carver, but the exact disposition of the judgement
is lost to memory right now.
--
____________________________________________________________________
Chuck Ross KC9FL South Holland, IL ckr...@ais.net
Jim Andrews
In article <4po652$9...@biosun.harvard.edu>,
DPi...@world.std.com (Richard D Pierce) wrote:
[preliminary snip]
>I'd like to take the discussion one step further and point out a
>generalization of the principles invloved. That generalization is the
>concept of resonance and how energy moves back and forth in resonant
>systems.
YES! Make it required reading, or put it in the FAQ.
[ quoted text deleted -- rgd ]
>Whether it be at the fundamental resonance of a loudspeaker system, the
>undamped ringing of a breakup mode of a cone, the interaction of cables
>inductance and capacitance, whatever, the important thing to remember is
>NOT that energy is being stored, but that energy is being exchanged back
>and forth on a periodic basis: the system is resonating.
Semantics, Dick. Energy IS being stored at any instant in time, even
during resonance. It's either stored potentially, kinetically
(inductively), or some combination of the two. Many people have a
problem with "kinetic energy STORAGE". I suspect that's because our
junior high/high school teachers often call potential energy
(compressed springs, charged capacitors, a ball at the top of a
mountain, etc.) "stored" energy, but they call the energy of motion
"moving" energy. It's still stored -- otherwise, flywheels wouldn't
work.
>"Back EMF,", that ol' demon that many claim is such an evil culprit, is
>not a phenomenon in and of itself: it is a symptom of an underlying
>property of the system. The system is resonating. And it makes not one
>wit to the amplifier whether that resonance is due to a combination of
>two opposite electrical reactances or two opposite mechanical reactances,
>the effect is IDENTICAL.
Why would back EMF be related to resonance? If we define resonance as
sytemic oscillations (electrical or mechanical) due to either natural
or forced vibration near a system eigenvalue, we limit back EMF to
certain narrow frequency bands. Wouldn't you say that back EMF is an
undefeatable result of the transfer of energy between mechanical and
electrical domains?
[snip]
>Let's look at a mechanicallyresonance. This requires that we have two
>opposite reactances, specifically a mass and a stiffness or compliance.
Laymen should note here that compliance is simply the inverse of
stiffness. It is a trivial matter to recast the equations of motion
from mass/stiffness to mass/compliance -- just get the units right,
and everything falls out. (I'm not going to address the ridiculous
lengths one must go to in order to get the units right in the English
system, as opposed to the INCREDIBLY straightforward metric system.
The United States is advanced? Yeah . . .)
[snip]
>And so on and so forth the cycle proceeds, back and forth, energy being
>converted between its potential and kinetic form at a rate determined
>SOLELY by the stiffness of the spring and the mass of the, well, mass.
You have understandably left out the third lumped parameter --
damping. It should be noted that damping has at least two significant
effects on oscillation. One, in simple systems, it lowers the
resonant frequency. Two, it limits the amplitude of oscillation, and
can reach a value that is high enough to completely eliminate
oscillation altogether. A system released from some initial condition
in an "overdamped" state will not vibrate, but slowly approach a final
value. Mechanically, this can be visualized as lifting your car
bumper up and releasing the car. If your shocks (dampers) are shot,
the car will bounce on the suspension. If your shocks are really
cranked up, the car will simply settle back to its rest position.
Electrically, we can envision a charged capacitor in series with a
resistor and inductor. If we close a switch using a "low" value of
resistance, the voltage (and current) will ring about their zero
values, eventually dying to zero. If we add more resistance, we can
reach a point where ringing (resonance) no longer occurs. In forced
vibration (such as an amplifier driving a speaker), damping affects
the amplitude of motion, and changes the frequency at which the
speaker responds most freely to an applied voltage. It also changes
the system's "Q", which is to some extent a measure of the size of the
frequency band over which a system wants to oscillate.
[snip]
>mass in kilograms, and C is the compliance in Newtons/meter.
[ quoted text deleted -- rgd ]
Oops! meters/Newton -- the old units bug strikes even DP ;)
[many more lines of quoted text deleted, come on people,
we don't need to quote text if we're just going to agree
with someone -- rgd]
Very well put, Dick. Maybe it will sink in (pun intended), but I
doubt it. You left out the green pens.
| Jim Andrews
"I wasn't born, so much as I fell out" | MBT, Inc.
| Basset Sound
The Clash | The Fidgets
Gene Steinberg
>Stereophile seemed not to pay the slightest attention to this, and
>Carver was really pissed and ran a string of ads in 'Sphile
>complaining about his mistreatment and the dishonesty of the second
>review.
>Stereophile was upset about this and there was a court battle which
>blocked Carver's advertising in the magazine, and also kept the
>magazine away from Carver, but the exact disposition of the judgement
>is lost to memory right now.
The exact trigger of the lawsuit was Carver running a series of ads
containing reviews of one of their amplifiers. One was the Stereophile
review, unfavorable, and the others, a bunch of them, were favorable
reviews from other magazines. None of these reviews had anything to do
with the amplifier that was part of the original "Carver Challenge,"
but another solid state amplifier one (as I recall) that was modeled
to sound the same as Carver's own Silver Seven tube amp.
In a sense, by putting Stereophile's review up against the
competition, they were denigrating that review's value because it
differed so much from the others.
When Stereophile sued, Carver's countersuit against Stereophile was to
the effect that the magazine had engaged in a deliberate campaign to
attack the company's products that had resulted in the company losing
business.
The actual court settlement included an agreement from Stereophile not
to mention Carver in the pages of their magazine for a period of a
couple of years.
You'll notice, if it means anything, that Carver products have gotten
favorable reviews in Stereophile and their home video magazine since
Bob Carver left the company. "Very interesting" as they used to say on
that old TV comedy show.
--
Peace,
Gene
Richard D Pierce
In article <4ppdbl$r...@eyrie.graphics.cornell.edu>, Rndmtn
<rnd...@aol.com> wrote:
>Hmmmmm, more people harping on cables.
>
>So what's new.
>
>I'm sorry guys, especially Gene. I did do a sighted test and compared
>cables and I saw a difference: on a spectrum analyzer. One showed one
>speaker cable was able to hit 25 hz versus another which barfed out at
>35. Sorry. Differences do exist and it seems that regardless of the
>existence of double blind followers: some numbers don't lie either.
If you measured significant differences using a spectrum analyzer at
25 to 35 Hz between speaker cables, then I submit, as one who has been
doing these sorts of experiments for a quarter centurym, that the
problem lies not in the cables, but in the experimental setup. The
technical term for this problem is "pilot error."
Sorry, but you are making a rather extraordinary claim here. Of the
thousands upon thousands of just such measurements I have performed,
the difference you claim has never once shown up that was not provably
due to purely and exclusively experimental errors (such as, in the
case of FFT based analyzers, improper windowing and such) that were
complete;y resolvable and utterly unconnected with the devices under
test.
In making such an extraordinary claim, you would be wise to detail a
bit better precisely WHAT and HOW you are measuring. Your claim is
strongly suspect and without ANY supporting data other than your word,
can't be taken very seriously.
Rndmtn
> What numbers? In the first place it seems pretty unlikely that there
> would be a big difference in bass response between 8TC and the
> unspecified Audioquest cable.
> In the second, you quote two numbers and a 'hit/barf' in support of
> your argument. This is an unconventional notation with which I am
> not familiar. Perhaps you could enlighten us with a little more
> detail on your actual test procedure, equipment used and results
> gained.
> You know, numbers.
Numbers , numbers. Everyone wants numbers. Well, I just want to
listen to my CDs. Without sibilance. I tried various cables to see
if one could help. In order to double check I tried some informal
inquiries, not under some electrical engineering scheme.
Okay, first, all I did was lock at a particular sequence in Enya. I
changed cables accordingly. Had my friend with the specturm analyzer
place the mike at a single location and we just played the track.
Identical passage. Identical duration. The little dots on the
analyzer were not the same. Audioquest did not budge past a certain
point on the meter. Kimberkable did. This confirmed to me that what
I was hearing was not a delusion. I was hearing more bass from one
cable versus another one. A specturm analyzer doesn't lie.
Oh, yeah. We also did a sine wave sweep from 10 to "I can't stand the
whistle frequencies." Kimber seemed to go through the sweep better.
I saw more low frequencies and more high frequencies. The analyzer is
my friends. I don't know the brand. I do know he spent roughly about
a thousand dollars on this little box. I didn't bother asking him the
details of it all. I'm not going to buy one.
This can be repeated by anybody. I'm not an engineer and I am not
going to die if I can't prove it with every bit of data. I have a
life. I need to work. Of course, this type of experiment will not
tell you anything about soundstaging and imaging. I wasn't really
worried about that problem. I just wanted the sibilance to stop or at
least become more tolerable.
Going about with all this engineering proofs is fine. If you need it,
fine. But I don't have the time for it. I don't think alot of people
really have time for it, unless you are seriously obsessed. If so,
one should perhaps reevaluate things in life.
Why are people burning churches in the South? That's important. Why
must I do a double blind test on a cable? That's not important in the
grand scheme of life.
If it works, use it. Kimberkable works. I use it. I tried,
Audioquest, Goertz, Flatline, Monster, lampcord, RadioShack. They
didn't do it for me. Of course there are people who wil tell me, you
didn't hear a difference. Then why should a mechanical device show
one can go deeper than another down a sine sweep?
Sometimes if it sounds like there is more bass, there is more bass
there.
No biggie.
d maruyama
Dennis Moore
I don't know how long after the actual Carver challenge the reference
amp's identity was revealed. But some time later it was revealed to
be the Conrad-Johnson top of the line amp.
Later versions of the T-mod series were based on tranfer functions of
Carver's own tube amp, the Silver Seven's.
Dennis
Steve Nugent
|> Let me put it another way. If you put a battery across a coil,
|> some energy will be stored in the resulting magnetic field. If you
|> remove the battery, the field will collapse and some of that energy
|> will be released, causing a spark. If you put a battery across the
|> terminals of a speaker, some energy will be stored in the mechanical
|> displacement of the voice coil. When the battery is removed, the
|> energy will be released. There is a set of electromechanical
|> analogs that allows you to represent the circuit behavior of the
|> driver as pure R's, L's, and C's. There is no need to perform the
|> tedious (to an electrical engineer) electromagnetic and mechanical
|> calculations to predict the terminal impedance characteristics once
|> the electrical analog has been defined. Nor do we need a special
|> component, the "back EMF generator
-clip
|> If course, you're perfectly entitled to disagree with the
|> technical points I have just made, and I encourage you to write at
|> length about it so that you might catch Dick Pierce's attention.
|> Then we might have a good laugh and learn even more about this
|> interesting subject. Or don't. It's up to you.
|>
|> Does that clear the whole topic up?
This helps considerably, and I can understand what you have said. I
have 20 years experience doing digital design and transmission-line
analysis so you have not wasted your keystrokes.
I am curious, though, of the difference in the characteristics of the
following two scenerios: A loudspeaker driver, which includes spring
mechanisms that try to return the cone to a detent position in the
absence of signal, as compared to a second system comprising the same
coil and cone mass, but without the spring mechanism that returns it
to the detent position. Instead the second system includes a friction
equivalent to the spring of the loudspeaker. In other words, with an
applied pulse function, the force applied to both coils is identical
for some time T. The loudspeaker is displaced and then springs back
when the applied signal stops and the second system cone is displaced
by some amount and stays there. After the drive is removed, the
second system is perfectly static. The first system must recover due
to the springs. Doesn't this recovery cut flux lines in the magnet
assembly and as a result drive a current back into the cable adding to
the energy stored in the inductance of the coil? I believe that the
second system has only the energy stored in the inductance of the coil
that is driven back into the cable.
Richard D Pierce
In article <4q1l73$8...@eyrie.graphics.cornell.edu>,
Rndmtn <rnd...@aol.com> wrote:
>> What numbers? In the first place it seems pretty unlikely that there
>> would be a big difference in bass response between 8TC and the
>> unspecified Audioquest cable.
>
>> In the second, you quote two numbers and a 'hit/barf' in support of
>> your argument. This is an unconventional notation with which I am
>> not familiar. Perhaps you could enlighten us with a little more
>> detail on your actual test procedure, equipment used and results
>> gained.
>
>listen to my CDs. Without sibilance. I tried various cables to see
>if one could help. In order to double check I tried some informal
>inquiries, not under some electrical engineering scheme.
Gee, you're making inquiries into the realm of electrical engineering
without using electrical engineering paradigms. INteresting approach,
indeed.
>Okay, first, all I did was lock at a particular sequence in Enya. I
>changed cables accordingly. Had my friend with the specturm analyzer
>place the mike at a single location and we just played the track.
>Identical passage. Identical duration. The little dots on the
>analyzer were not the same. Audioquest did not budge past a certain
>point on the meter. Kimberkable did. This confirmed to me that what
>I was hearing was not a delusion. I was hearing more bass from one
>cable versus another one. A specturm analyzer doesn't lie.
What kind of "spectrum analyzer?" How long was the sequence? Did you
bother seeing what the direct analysis of the signal looked like?
These and many other answers profoundly affect the data you get and it
reliability and have NOTHING to do with cables.
>Oh, yeah. We also did a sine wave sweep from 10 to "I can't stand the
>whistle frequencies." Kimber seemed to go through the sweep better.
>I saw more low frequencies and more high frequencies.
"more low frquencies and more high frequencies" More of those precise
engineering terms which communicate well the quantitative results of your
experiment.
>The analyzer is
>my friends. I don't know the brand. I do know he spent roughly about
>a thousand dollars on this little box. I didn't bother asking him the
>details of it all. I'm not going to buy one.
So it's probably a White Instruments or a GoldLine 1/3 octave real time
analyzer. It is NOT a spectrum analyzer. The filters at 20 Hz, because
the bandwidth there is a mere 4 Hz or so wide, meaning the response time
of the filter cannot be any faster than about 1/2 second or so. So any
small error in the length of your "locked sequence" is capable of
completely skewing the data that renders any conclusion about cables
utterly meaningless.
>This can be repeated by anybody.
Sure can, and when repeated by myself and hundreds of other
researchers who are a hell of a lot more careful to eliminate such
gross sources of experimental error, the results are vastly different.
>I'm not an engineer and I am not going to die if I can't prove it with
>every bit of data.
No, you probably won't even feel bad. But your assertion and your
theory have already died a rather horrible death from lack of
experimental careand nursihment. I am sorry for your loss.
>Of course, this type of experiment will not
>tell you anything about soundstaging and imaging.
Now will it tell you anything about the frequency response if
cables. The analyzer bandwidth is two wide, the resolutuion is far too
course, etc.
>I wasn't really worried about that problem.
Nor, would it seem, were you concerned with gross experimental and
procedural errors, the severe limitations of the instruments in making
such measurements, time-frequency ambiguity, and so on.
And that's okay. You don't NEED to worry about all that. Just don't
claim the data that comes out of it has any meaning whatsoever,
though.
> I just wanted the sibilance to stop or at
>least become more tolerable.
Then fix the problem where it occurs.
>Going about with all this engineering proofs is fine.
Yes, it's fine when you make sure that your "experiment" is not so
horribly and irretrievably crippled by such overwhelming sources of
error that it's giving you so much false data as to render any
conclusion based on that data useless.
>If it works, use it. Kimberkable works. I use it. I tried,
>Audioquest, Goertz, Flatline, Monster, lampcord, RadioShack. They
>didn't do it for me. Of course there are people who wil tell me, you
>didn't hear a difference. Then why should a mechanical device show
>one can go deeper than another down a sine sweep?
Because you screwed up the experiment, plain and simple, that's why.
>Sometimes if it sounds like there is more bass, there is more bass
>there.
That may be, but you have yet to present a single piece of data from a
repeatable, reliable experimental procedure so support the assertion. Use
any cable you want, and use it for whatever reason you want. But don't
take bad data from a badly designed instrument and use it to bolster your
personal choice. Use the cable and be done with it. Nobody will argue.
SDuraybito
> These other "theories" however, fail grossly at predicting
> observable reality. Feedback loops DO NOT interact with "back EMF"
> the way some in the press and manufactory say they do: the
> phenomenon that their "theories" predict simply do not occur. The
> notion of spikes and cones and other such trickery "sink" energy is
> completely contradicted both by real theory AND observations.
As I see it, there are three different sorts of claims being made by
the resonance "crowd:"
1. That energy can be absorbed so that it cannot affect the rest of
the system.
2. That energy can be dissipated away from the system.
3. The various materials can be used to tune the frequency of energy
being exchanged back and forth on a periodic basis.
Can you categorically debunk all three, please?
Pat Wallace
In article <4ppdbl$r...@eyrie.graphics.cornell.edu> rnd...@aol.com
(Rndmtn) writes:
> I'm sorry guys, especially Gene. I did do a sighted test and
> compared cables and I saw a difference: on a spectrum analyzer. One
> showed one speaker cable was able to hit 25 hz versus another which
> barfed out at 35. Sorry. Differences do exist and it seems that
> regardless of the existence of double blind followers: some numbers
> don't lie either.
This is a remarkable result, and I'd be very interested in a few more
details.
What amplifier and speaker (or load) did you use? What type of
spectrum analyzer? How was it connected? What type of signals did
you use for the tests? And how many dB down corresponds to "barfed
out"?
Patrick Wallace
Richard D Pierce
In article <4q1nft$8...@eyrie.graphics.cornell.edu>,
Steve Nugent <nug...@ssd.intel.com> wrote:
>In article <4plcgq$s...@biosun.harvard.edu>, hen...@nortel.ca writes:
>
>|> some energy will be stored in the resulting magnetic field. If you
[double clip]
>This helps considerably, and I can understand what you have said. I
>have 20 years experience doing digital design and transmission-line
>analysis so you have not wasted your keystrokes.
>
>I am curious, though, of the difference in the characteristics of the
>following two scenerios: A loudspeaker driver, which includes spring
>mechanisms that try to return the cone to a detent position in the
>absence of signal, as compared to a second system comprising the same
>coil and cone mass, but without the spring mechanism that returns it
>to the detent position. Instead the second system includes a friction
>equivalent to the spring of the loudspeaker.
Only one problem: there is no such thing as (and there can never be)
"a friction equivalent to the spring." Claiming such is akin to
claiming that you have created a resistive equivalent of a capacitor.
The spring, just like a capacitor or inductor, is a reactive
device. It reacts by pushing back on whatever tries to squeeze it. Put
energy in to it, and it puts energy back in to the system. It's an
energy storing device. A friction, just like a resistor, is an energy
dissiptive mechanism. Put energy into it, and you can't get it back,
it's gone. In the case of both frictions and resistors, it's turned to
heat and no longer participates in the dynamics of the system.
> In other words, with an
>applied pulse function, the force applied to both coils is identical
>for some time T. The loudspeaker is displaced and then springs back
>when the applied signal stops and the second system cone is displaced
>by some amount and stays there. After the drive is removed, the
>second system is perfectly static. The first system must recover due
>to the springs. Doesn't this recovery cut flux lines in the magnet
>assembly and as a result drive a current back into the cable adding to
>the energy stored in the inductance of the coil? I believe that the
>second system has only the energy stored in the inductance of the coil
>that is driven back into the cable.
And, as such, would be a device useless for the reproduction of
sound. In your system, the cone would move to it's designated
position, accelerated there by a force equal to the Bl product of the
voice coil/magnet times the current through the coil and, once the
current is removed after time T, would stay there, never to return.
Henry did an excellent job describing the reasons systems work as well
as they do: when operating in the mass controlled region (above
resonance which, it should be noted, requires the system have both
mass and stiffness), the excusrion goes as the inverse square of the
frequency. And that, it so happens, perfectly matches the radiation
resistance seen by the cone. (Another way to look at it is that above
resonance, the total 'volume velocity' of the cone is constant,
independent of frequency: take the area of the cone, mutliply it times
the velocity of the cone vs frequency: guess what: it's a number
that's constant above resonance.)
No, you STILL don't need any magic to explain what's happening: simply
recognizing the phenomenon as a mechanically resonant system is
suffice to completely explain and predict the behaviour of
loudspeakers in their piston region. The technique is simple, powerful
and has yet to be shown to have any weaknesses.
hen...@nortel.ca
Steve Nugent (nug...@ssd.intel.com) wrote:
: This helps considerably, and I can understand what you have said. I
: have 20 years experience doing digital design and transmission-line
: analysis so you have not wasted your keystrokes.
It was late in the evening and I got a little poetical at the end,
sorry.
: I am curious, though, of the difference in the characteristics of the
: following two scenerios: A loudspeaker driver, which includes spring
: mechanisms that try to return the cone to a detent position in the
: absence of signal, as compared to a second system comprising the same
: coil and cone mass, but without the spring mechanism that returns it
: to the detent position. Instead the second system includes a friction
: equivalent to the spring of the loudspeaker. In other words, with an
: applied pulse function, the force applied to both coils is identical
: for some time T. The loudspeaker is displaced and then springs back
: when the applied signal stops and the second system cone is displaced
: by some amount and stays there. After the drive is removed, the
: second system is perfectly static. The first system must recover due
: to the springs. Doesn't this recovery cut flux lines in the magnet
: assembly and as a result drive a current back into the cable adding to
: the energy stored in the inductance of the coil? I believe that the
: second system has only the energy stored in the inductance of the coil
: that is driven back into the cable.
It's a good question. What you've done is changed the driver from
a second-order system to a first-order system by eliminating one of
the two reactive elements (the spring) required for oscillatory
response. Alternatively, you can say you've made the compliance
infinite, so that the frequency of resonance goes to zero. Such a
system, when left to recover on its own from some input, will always
show a diminishing exponential response, with no sinusoidal component
of motion.
When you apply a signal to this springless driver, the cone will
begin to move, as you say, and energy of motion will be stored in the
moving mass. When the signal is removed, the kinetic energy will be
dissipated by the frictional element and the cone will gradually come
to rest. During the time that the cone is slowing down, the cutting
of field lines will cause current to flow in the voice coil if there
is a circuit path connected to the driver terminals. Current flow
through the resistance of the voice coil and external circuitry will
also dissipate energy and cause the cone to slow down faster than if
the driver terminals are open-circuited.
If we ignore the parasitic inductance and capacitance of the voice
coil itself, the fact that the modified driver is a first-order system
mechanically means it will appear as a first-order electrical network
as well. The one-to-one correspondence of mechanical and electrical
energy storage mechanisms makes this so.
So, the answer to your question, in a nutshell, is that there is
still the energy of motion stored in the moving mass to account for.
If you eliminate the moving mass, as well, the driver will then look
like a plain old resistor, I think, where the measured value of
resistance will be higher than the nominal coil DCR because of the
effect of back EMF. But the resistance will be dynamically nonlinear
because a short time after a DC voltage is applied, the coil will be
shot out of the gap and the back EMF effect will dissapear.
-Henry
hen...@nortel.ca
Dan Prysby
rnd...@aol.com (Rndmtn) wrote:
[ quoted text deleted -- jwd ]
> Numbers , numbers. Everyone wants numbers. Well, I just want to
> listen to my CDs. Without sibilance. I tried various cables to see
> if one could help. In order to double check I tried some informal
> inquiries, not under some electrical engineering scheme.
>
> Okay, first, all I did was lock at a particular sequence in Enya. I
> changed cables accordingly. Had my friend with the specturm
> analyzer place the mike at a single location and we just played the
> track. Identical passage. Identical duration. The little dots on
> the analyzer were not the same. Audioquest did not budge past a
> certain point on the meter. Kimberkable did. This confirmed to me
> that what I was hearing was not a delusion. I was hearing more bass
> from one cable versus another one. A specturm analyzer doesn't lie.
I would caution anyone without good technical knowledge of such
measurement techniques to stop trying to make these scientific
tests. Your approach is highly suspect due to your lack of
understanding of sources of error.
For example, those who use scopes - the first thing a good tech will
do is calibrate his probes - has any of you ever done that? how? How
do you reference your ground?
For the spectrum analyzer - I would want to know: what is the sampling
rate and bandwidth of the spectrum analyzer vs the frequency and
bandwidth of the signal you are measuring? Do you know what errors
result if your bandwidth is too wide or your sampling frequency is too
fast? Your spectrum analyzer will give you a number but it will not
tell you if it is correct. Why use a microphone? Wouldn't direct
measurement of the electrical signal at the speaker terminals be
better and eliminate some sources of error?
I have seen inexperience engineers measure good results when they are
really bad, and bad results when they are really good.
I, for one, am skeptical.
Dan Prysby
Rndmtn
Question. Is engineering more important than listening?
Question. Do you only buy things if things measure correctly or if it
sounds good to you, not someone else, but you?
Question. Is the everyday consumer going to need live or die by
engineering facts?
Now. I was just sharing what I saw. I make no claims that it was an
absolute. I was just messin around with a very expensive toy. I
really could care less if one person agrees or disagrees with me. It
is not my machine. I am not going to force my friend to show it to
me. He is a rather busy engineer living on contracts.
Fine. Maybe I'm wrong. But maybe I'm not. It really doesn't matter
does it? Unless it is the center and circumference of your life.
By the way, this was a test to see if I would get a whole lot of
ascerbic responses. The cables debate seems to possess the same tone
that has enveloped the digital vs analog. I was testing the waters if
I could actually ask about which cable help certain aspects of my
system. (Tonally, I think that I got a better balance now. Of
course, I did not measure every frequency and I won't.) You average
inquiring mind will not find this forum welcome. A need to feel
superior to another person seems to be rather counterproductive. It
becomes a major turn off. (This turnoff often visits you when you
enter a high end shop with a T-shirt and jeans. It changes when you
flash the gold card.)
Perhaps more of a sense of friendly cooperation should be pursued
versus bickering. Some say there are no audible differences. Others
say yes. Couldn't both be right. In certain cases maybe there are no
differences. In certain cases maybe there are.
If all else fails, drink a gallon of good Sierra Nevada ale. It won't
matter then. Sometimes I think many people in audio need more beer.
It does make the tonal balance alot better. Really!
d maruyama
Richard D Pierce
In article <4q4pij$e...@agate.berkeley.edu>, Rndmtn <rnd...@aol.com> wrote:
>Question. Is engineering more important than listening?
>Question. Do you only buy things if things measure correctly or if it
>sounds good to you, not someone else, but you?
>Question. Is the everyday consumer going to need live or die by
>engineering facts?
>Now. I was just sharing what I saw. I make no claims that it was an
>absolute. I was just messin around with a very expensive toy. I
>really could care less if one person agrees or disagrees with me. It
>is not my machine. I am not going to force my friend to show it to
>me. He is a rather busy engineer living on contracts.
>
>Fine. Maybe I'm wrong. But maybe I'm not. It really doesn't matter
>does it? Unless it is the center and circumference of your life.
It would seem Mr Rdnmtn is suffering from eating a bunch of sour
grapes.
>By the way, this was a test to see if I would get a whole lot of
>ascerbic responses. The cables debate seems to possess the same tone
>that has enveloped the digital vs analog. I was testing the waters if
>I could actually ask about which cable help certain aspects of my
>system.
No sir, you did not "ask questions." You made very specific technical
assertions, assertions which are testable, assertion which were, in
fact, tested and found wanting. You made very specific claims about
the low-end frequency response of cables, assertions for which you
have provided no support, and which are unsupportable technically.
Myself and others pointed out several procedural flaws in your method.
You responded by crying foul about whether or not we measure or we
listen.
Well, Mr. Rndmtn, THESE WERE YOUR MEASUREMENTS! YOU made these claims
about measurements, no one else did. If you don't think the
measurements mean anything, then what was the point in talking about
them. Indeed, if they don't mean anything, what was the point in even
doiing the measurement to begin with.
On the assumption you even did the measurements to begin with, the
data is useless. Your attempt to bolster your personal preference by
positing pretty bogus "measurements" has not helped the rational
people on either side of the debate. It has only helped to provide
more fodder for the irrational deconstructionists, those who are
unwilling to make any positive contributions to the debate.
>(Tonally, I think that I got a better balance now. Of
>course, I did not measure every frequency and I won't.)
>You average inquiring mind will not find this forum welcome.
I get a LOT of mail from such people, thanking me for the help I
provide. In the vanishing minority are people who cannot disconnect
their fragile egos from their equipment decisions. Without more
support, I would suggest that you do not have a handle on the "average
inquiring mind" since you do not represent the average, you, like
everyone else, represent only yourself.
I would remind again that it was YOU who brought these measurement
data into the public eye. No one else.
>A need to feel
>superior to another person seems to be rather counterproductive. It
>becomes a major turn off.
Look, your measurements were bogus. Plain and simple. That's your
fault. You're blaming the messenger for the content of the message.
>Perhaps more of a sense of friendly cooperation should be pursued
>versus bickering.
Your were provided with objective reasons why your measurements were
highly suspect.
>Some say there are no audible differences. Others
>say yes. Couldn't both be right.
Show, by quoting articles, where anyone in this particular thread,
made ANY specific claims that differences were not audible. I NEVER
made ANY statement that differences were not audible, nor did I make
ANY statements that they were. I focused on one very specific aspect
of your assertions: the unreliability of your data due to procedural
errors. There was never a discussion about audibility.
>In certain cases maybe there are no
>differences. In certain cases maybe there are.
But the data that YOU COLUNTARILY provided, because of it's provable
unreliability, does nothing to prove anything one way or another.
>If all else fails, drink a gallon of good Sierra Nevada ale. It won't
>matter then. Sometimes I think many people in audio need more beer.
>It does make the tonal balance alot better. Really!
Yes, and there are those that claim that it makes you a better driver,
a better lover, a better thinker, a better worker, a better person.
The data has yet to support any of these assertions.