New Age "wine enhancement"
RichD
"Our trade secret, proprietary design creates a
harmonically balanced resonate frequency that
affects the water molecules structure"
Proving, again, that science doesn't have all the answers...
--
Rich
Eric Gisse
> http://www.wineenhancer.net/wine-accessories-supplies-how.asp
>
> "Our trade secret, proprietary design creates a
> harmonically balanced resonate frequency that
> affects the water molecules structure"
Physicists call it a microwave. Why would you want to heat up your
wine?
>
> Proving, again, that science doesn't have all the answers...
Hippie fucks like you have even fewer answers, and produce _zero_
working technology.
>
> --
> Rich
CWatters
"RichD" <r_dela...@yahoo.com> wrote in message
news:1183017112.3...@g37g2000prf.googlegroups.com...
LOL..
"It is composed of a combination of organic (epoxy) and non-organic
non-magnetic metals (copper and others) placed in a matrix with various
crystals (12) also known for their specific vibrational frequencies. "
Which begs the question .... Are there any organic magnetic metals? or is
this "organic" in the sense that pesticides _were_ used to grow the copper?
Uncle Al
http://www.mazepath.com/uncleal/crap.htm
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2
Lawrence Leichtman
RichD <r_dela...@yahoo.com> wrote:
> wine-accessories-supplies-how.asp
BS, BS, BS, BS
Gareth Magennis
It also proves that whoever wrote that web page has no idea about grammar,
spelling or punctuation.
Gareth.
Ethan Winer
> technology.
LOL, that's a great come-back. It kills me when "believers" diss real
science, but of course they have nothing of their own to show.
Richard Crowley
On the other hand we have a rich history of "real science"
that seemed just as valid in its time, but in retrospect is
embarassing at best. And I wouldn't bet my life that 100%
of everything we think of as "real science" today will stand
the test of time and further research.
Gareth Magennis
"Richard Crowley" <rcro...@xp7rt.net> wrote in message
news:5ei6c3F...@mid.individual.net...
Agreed, and I think the biggest mistake made is to think that Science deals
with "facts". It does not, it merely puts forward hypotheses that fit
certain observations. A particularly good hypothesis (theory) will also
predict certain outcomes that may later be observed to be as predicted.
These theories are only designed to be "true" until an observation
condtradicts it, or it is updated by a better version, they are absolutely
NOT describing things that are actually true or are known facts. There are
no known facts at all. (except perhaps in Mathematics, which precisely
defines the facts it is proving)
Gareth.
Don Pearce
Even maths doesn't deal in facts. All proofs rest on axioms - which
are pretty good assumptions about how the world works, but they are
just assumptions. So a proof will really read "Such and such is
proven, assuming that...".
d
--
Pearce Consulting
http://www.pearce.uk.com
UC
You're fucked in the head. Get the hell out of here...
Sjouke Burry
> http://www.wineexxxxxxxxxxxxxxxxxxxxxxxxxxxxxs-how.asp
>
> "Our trade secret, proprietary design creates a
> harmonically balanced resonate frequency that
> affects the water molecules structure"
>
> Proving, again, that science doesn't have all the answers...
>
> --
> Rich
>
RichD
Dudes, it pains me to be the bearer of bad news,
but you are thick witted bastards.
No offense intended.
--
Rich
Don Pearce
wrote:
Brilliant reasoning - I've never seen such an astute application of
logic. Can you tell me how long it took you to work through it and
arrive at this line of reasoning? Did you have help?
Sorry, - you don't possess sufficient wit to cause offence to anybody.
Gareth Magennis
"Don Pearce" <nos...@nospam.com> wrote in message
news:4691ee86....@news.plus.net...
The bit about Maths I meant was that you can say that the statement "1 + 1 =
2" is true, it IS a fact because we have defined all the rules that make
this a fact. You cannot, with the same certainty, say that this chair I am
sitting on really exists, or exists in the way that I think it does. All
science is based on assumptions of what we think reality is.. Any of these
assumptions are subject to change or revision at some point, should they be
shown to be incorrect. (For instance, Quantum Physics can now show the same
particle to be in 2 different places at the same time). Our "knowledge" of
the world is not knowledge, but Opinion. It's a good game though.
Gareth.
Jasen
>
> "RichD" <r_dela...@yahoo.com> wrote in message
> news:1183017112.3...@g37g2000prf.googlegroups.com...
>> http://www.wineenhancer.net/wine-accessories-supplies-how.asp
>>
>> "Our trade secret, proprietary design creates a
>> harmonically balanced resonate frequency that
>> affects the water molecules structure"
>>
>> Proving, again, that science doesn't have all the answers...
>>
>
> non-magnetic metals (copper and others) placed in a matrix with various
> crystals (12) also known for their specific vibrational frequencies. "
sounds like a computer circuit, epoxy and copper PCB. abd quartz
crystals known to oscillate at certain frequencies (frequencies that are
typically printed on the case) only problem is I think the case is
zinc plated steel,
> Which begs the question .... Are there any organic magnetic metals? or is
> this "organic" in the sense that pesticides _were_ used to grow the copper?
:) copper is a funguicide...
--
Bye.
Jasen
Ethan Winer
> Dudes, it pains me to be the bearer of bad news,
> but you are thick witted bastards.
This is typical. If you had something - anything! - of substance that
supports your position you'd have stated it. But since you don't, all that's
left is insults.
I'll humor you for the moment. That page claims the product can improve the
taste of wine basically via osmosis, right through the glass bottle without
contacting the wine itself. To wit, "The resonance occurs right through the
glass." I'd love to hear you explain how this can happen. Please be
specific! Extra points if you can explain what "resonance" has to do with
the process.
--Ethan
Don Bowey
Magennis" <sound....@btconnect.com> wrote:
QP can NOT show that. It can only show that at least one model, of the
many, of the String *theories* shows that.
Don Bowey
74GdnWOQA-1VsBjb...@giganews.com, "Ethan Winer" <ethanw at
ethanwiner dot com> wrote:
Show a little sympathy. He is probably unemployed from the Consumer Sales
industry where he sold monster cables until they became totally debunked.
I enjoy good wines, the industry of which already has it's share of quacks,
and I think one more shouldn't hurt too much. It ranks with teaching that
the wine glass should be held by two fingers on the rim of the base and then
held up as though it were a dirty diaper.
Don
Benj
I. Care wrote:
>
> I think the OP needs to buy some shakti stones to enhance his audio
> system while he drinks his treated wine. Then he will feel physically
> lighter with an empty wallet.
You beat me to it! I was about to say that this sounds VERY much like
the nonsense audiophiles spend thousands on to (allegedly) hear every
last nuance out of their systems.
They need to make these wine treaters in larger models so you can sit
a speaker cabinet in it! I'm sure for a mere $20 grand a piece of so,
I'd be able to hear things in my favorite recordings I never heard
before! :-)
But it's all a little advanced for a person an my level. I'm still
trying to afford the special cables that have to always be installed
one way and come in different models according to the type of music
you play.
Ron Capik
> < ...snip... >
>
> But it's all a little advanced for a person an my level. I'm still
> trying to afford the special cables that have to always be installed
> one way and come in different models according to the type of music
> you play.
Gee, I thought the really good cables could be retrained. ;-)
Later...
Ron Capik <<< cynic in training >>>
--
Ron Capik
Don Bowey wrote:
> On 6/29/07 1:44 AM, in article HNidnZAyHul...@bt.com, "Gareth
> Magennis" <sound....@btconnect.com> wrote:
> < .....snip.. >
> >
>
> . Any of these
> > assumptions are subject to change or revision at some point, should they be
> > shown to be incorrect. (For instance, Quantum Physics can now show the same
> > particle to be in 2 different places at the same time).
>
> QP can NOT show that. It can only show that at least one model, of the
> many, of the String *theories* shows that.
>
...or, they may just be in the same place in their own little oddly folded
time space manifolds. ;-)
Later...
Ron Capik
--
Don Bowey
Capik" <r.c...@worldnet.att.net> wrote:
Yes! ;-)
But seriously, I think they built in some faulty logic which allows, for
example, that a noise burst (local or galactic) that is detected in two
different places at the same instant, is proof that it actually "exists" at
each location, rather than each being an energy copy of the other. In my
example, I assume equal distance between the source and the two receiving
locations so there is no conflict with General Relativity.
Don
Stephen J. Rush
Don't forget the $295 hand-turned rosewood volume control knob and the
little stands that hold your speaker cables off the floor, so the signal
won't leak out. No kidding. Feed "audiophoolery" to your favorite search
engine for some laughs.
Ethan Winer
> Show a little sympathy.
LOL, he started it with, "you are thick witted bastards."
--Ethan
James Silverton
??>> I. Care wrote:
??>>>
??>>> I think the OP needs to buy some shakti stones to enhance
??>>> his audio system while he drinks his treated wine. Then
??>>> he will feel physically lighter with an empty wallet.
??>>
??>> But it's all a little advanced for a person an my level.
??>> I'm still trying to afford the special cables that have to
??>> always be installed one way and come in different models
??>> according to the type of music you play.
Cables do leak if you believe Comcast. A little while ago, I
came home to find some repairmen digging away in front of my
house. They said that the FAA had detected signal leakage from
their cable and they had to replace it!
James Silverton
Potomac, Maryland
E-mail, with obvious alterations:
not.jim.silverton.at.verizon.not
Jose
Yes, cables will leak RF if they are defective. RF is such a high
frequency that capacitance becomes important. Speaker cables only carry
audio.
Jose
--
You can choose whom to befriend, but you cannot choose whom to love.
for Email, make the obvious change in the address.
RichD
> I'll humor you for the moment. That page
> claims the product can improve the taste of
> wine basically via osmosis, right through the glass
> bottle without contacting the wine itself.
oh then I guess light can't heat a bottle of liquid,
right through the glass!
> I'd love to hear you explain how this can happen.
You scientists, such skeptics!
Drink some grape, open your mind!
> Extra points if you can explain what "resonance" has to
> do with the process.
waves resonate...light, sound... do you
know what resonate means?
--
Rich
Karl Uppiano
"RichD" <r_dela...@yahoo.com> wrote in message
news:1183017112.3...@g37g2000prf.googlegroups.com...
> http://www.wineenhancer.net/wine-accessories-supplies-how.asp
>
> "Our trade secret, proprietary design creates a
> harmonically balanced resonate frequency that
> affects the water molecules structure"
>
> Proving, again, that science doesn't have all the answers...
Science answers utilitarian questions, not religious ones.
Stephen J. Rush
>> Cables do leak if you believe Comcast. A little while ago, I came home to find some repairmen digging away in front of my house. They said that the FAA had detected signal leakage from their cable and they had to replace it!
>
> Yes, cables will leak RF if they are defective. RF is such a high
> frequency that capacitance becomes important. Speaker cables only carry
> audio.
Even with broadband RF, I find it hard to believe that a *buried* coax
cable could radiate enough to interfere with aircraft communications. I
wonder if Comcast was looking for an illegal splitter?
BTW, that-high performance volume control knob I mentioned earlier was
beechwood, not rosewood, but the price was even higher than I remembered.
The vendor actually claims that you can *hear* the difference between his
lacquered beechwood knobs and the stock bakelite ones. These are the
people who hear differences in an A-A test. That is, they claim to hear
differences between two runs of the *same* setup with the same program.
There is a physical basis for this effect. Any room (unless it's an
anechoic chamber) will have resonances that produce a comb-filter effect.
At high audio frequencies, moving your head a few inches can, indeed, make
an audible difference. Ethan Winer measured this effect, and published
the Bode plots. At some frequencies, a sharp peak in one location turns
into a sharp dip at the same frequency half a foot away. This is probably
the reason for the alleged audible effects of knobs, power cables (has
any of these "high-end audio" enthusiasts considered the miles of plain
old wire between his expensive 1-meter power cable and the generating
plant?), and the color of the listener's shirt.
Jose
> cable could radiate enough to interfere with aircraft communications.
Was that their claim? I would find it hard to believe too.
> I wonder if Comcast was looking for an illegal splitter?
Perhaps. Or they were just trying to save juice. It costs money to
leak signal into the dirt.
Jose
>> They said that the FAA had detected signal leakage from their cable and they had to replace it!
I bet he meant FCC. :)
James Silverton
??>> Was that their claim? I would find it hard to believe
??>> too.
??>>> They said that the FAA had detected signal leakage from
??>>> their cable and they had to replace it!
J> I bet he meant FCC. :)
J> Jose
Whatever! I later saw the crew working their way along the whole
street using some sort of detector and doing a lot of digging
and cable work not just at my house. I can't say that I found
the explanation all that believable either but I did not notice
any change in the TV signal :-) I've since gone to a fiber
optics connection so I don't suppose I'll ever really know what
they were up to.
Ethan Winer
> oh then I guess light can't heat a bottle of liquid,
> right through the glass!
Okay, so you're saying this device heats the wine through the bottle? I
suppose that's possible (though they don't claim that), but wouldn't heat
then ruin the wine?
>> I'd love to hear you explain how this can happen.
> You scientists, such skeptics!
> Drink some grape, open your mind!
I'm still waiting for your explanation. Not a side story about heat, but a
direct explanation of how this particular product works and what it does
specifically to the wine's chemical composition.
> waves resonate...light, sound... do you
> know what resonate means?
As an electronic engineer, musician, and acoustician, I most certainly do
know what resonance is. But obviously it's just a buzz word to you. Here's a
clue - waves don't resonate. :->)
--Ethan
Mark Lipton
> As an electronic engineer, musician, and acoustician, I most certainly
> do know what resonance is. But obviously it's just a buzz word to you.
> Here's a clue - waves don't resonate. :->)
Not to be too pedantic, Ethan, but -- given the wave-particle duality of
QM -- how else to characterize a phenomenon such as NMR?
Mark Lipton
--
alt.food.wine FAQ: http://winefaq.hostexcellence.com
Don Pearce
wrote:
>Ethan Winer wrote:
>
>> As an electronic engineer, musician, and acoustician, I most certainly
>> do know what resonance is. But obviously it's just a buzz word to you.
>> Here's a clue - waves don't resonate. :->)
>
>Not to be too pedantic, Ethan, but -- given the wave-particle duality of
>QM -- how else to characterize a phenomenon such as NMR?
>
>Mark Lipton
All those things we call subatomic particles or photons are in fact
nothing more than mathematical descriptions of certain limited aspects
of the behaviour of the universe at a small scale. The concept of what
they "are" is entirely meaningless in any sort of terms we could try
to understand.
Richard Crowley
> All those things we call subatomic particles or photons are in fact
> nothing more than mathematical descriptions of certain limited aspects
> of the behaviour of the universe at a small scale. The concept of what
> they "are" is entirely meaningless in any sort of terms we could try
> to understand.
So you are only a macro-visual existentialist? :-)
Don Pearce
That would be my limit. Anyone who thinks he can visualize the small
stuff is fooling himself.
:-)
Mark Lipton
>
> All those things we call subatomic particles or photons are in fact
> nothing more than mathematical descriptions of certain limited aspects
> of the behaviour of the universe at a small scale. The concept of what
> they "are" is entirely meaningless in any sort of terms we could try
> to understand.
Huh? QM is a mathematical description; photons are an example of a
subatomic particle whose existence is clearly supported by such
empirical phenomena as the photoelectric effect and diffraction. Or are
you making an oblique reference to any of the various superstring
theories, for which there is as yet not a shred of empirical support?
Don Pearce
wrote:
>Don Pearce wrote:
You are witnessing macro effects - that is all you can witness. You
can not make the leap from that to claiming there is a particle. The
very word is a macro-dimensioned conceit, and has no meaning in the
sub-atomic world. It is no more than a rather poor analogy in words we
can understand.
Mark Lipton
> You are witnessing macro effects - that is all you can witness. You
> can not make the leap from that to claiming there is a particle. The
> very word is a macro-dimensioned conceit, and has no meaning in the
> sub-atomic world. It is no more than a rather poor analogy in words we
> can understand.
OK, I'm with you now, Don. It's true that the best description of any
QM object is its wavefunction, which is nothing but a mathematical
construct and exists over all space. The problem I have is when you say
that because all I can witness are macroscopic phenomena (true, but
tautological) I cannot claim that there is a particle: all that I'm
saying is that we can claim that there is a photon; what word we use to
describe it is mere semantics and -- as you say -- there is no word that
will adequately describe a photon. Please note, though, that at various
points in my career I have been performing QM computations, so I learned
long ago to dispense with any attempt to visualize the species I was
studying as ultimately misleading and a waste of effort.
Don Pearce
wrote:
>Don Pearce wrote:
OK we agree. The problem is that it is far to easy to confuse the
label with the phenomenon. And as you conclude - as far as we are
concerned, the maths is really all there is.
Max Hauser
> Do not reply, please...
Mike, I don't know if that did much good, but thanks.
On the other hand, a recent conversation with someone who had something to
do with the history of newsgroups illuminated another angle that I thought
I'd mention. My informant described an experiment years ago. A popular
newsgroup (with serious subject matter, but attracting a lot of dross) was
converted to moderated form. Keep in mind that with newsgroups, just like
mailing lists, moderation is pre-facto -- you send the posting to the
moderator, who screens it. (Unlike the later, HTTP-based forum tools now
popular, which have central content control of course, therefore allow
after-the-fact edits.)
An effort was made to keep all irrelevant chat out of the new moderated
newsgroup. But the organizers found that a certain proportion of chat is
necessary to sustain interest. Even people who'd supported moderation would
drift away, otherwise. Other experience supported this observation.
Just food for thought. -- Max
Ethan Winer
> Not to be too pedantic, Ethan, but -- given the wave-particle duality of
> QM -- how else to characterize a phenomenon such as NMR?
If I had even an inkling about what QM and NMR are, I'd be glad to attempt
an answer! :->)
As for waves resonating, a room can resonate and waves are the result.
Likewise for an electrical circuit. In this case, the poster is clearly
clueless. These new-agers kill me when they use terms like resonance and
"energy" in a way that shows they have no idea what they're talking about.
--Ethan
Don Pearce
I really wouldn't be too picky if I were you, Ethan. You use the term
resonance when you are actually talking about modes. Easily done,
isn't it? ;-)
Mark Lipton
> Mark,
>
>> Not to be too pedantic, Ethan, but -- given the wave-particle duality
>> of QM -- how else to characterize a phenomenon such as NMR?
>
> If I had even an inkling about what QM and NMR are, I'd be glad to
> attempt an answer! :->)
http://en.wikipedia.org/wiki/Nuclear_magnetic_resonance
>
> As for waves resonating, a room can resonate and waves are the result.
> Likewise for an electrical circuit. In this case, the poster is clearly
> clueless. These new-agers kill me when they use terms like resonance and
> "energy" in a way that shows they have no idea what they're talking about.
I'd agree with you, but I'm too busy aligning my chakras with specially
tuned quartz crystals and placing the finishing touches on my Orgone box
to spare the brain cells needed to do so.
Mr.T
"Ethan Winer" <ethanw at ethanwiner dot com> wrote in message
news:lbCdndsN--eTMxfb...@giganews.com...
> > Not to be too pedantic, Ethan, but -- given the wave-particle duality of
> > QM -- how else to characterize a phenomenon such as NMR?
>
> If I had even an inkling about what QM and NMR are, I'd be glad to attempt
> an answer! :->)
Well he did mention Quantum Mechanics by name already, and NMR I assume is
Nuclear Magnetic Resonance.
It's not too hard to Google these things if you really wanted to know.
Obviously not I guess.
MrT.
Ethan Winer
> http://en.wikipedia.org/wiki/Nuclear_magnetic_resonance
Okay, thanks.
What's that have to do with wine? :->)
--Ethan
Ethan Winer
> I really wouldn't be too picky if I were you, Ethan. You use the term
> resonance when you are actually talking about modes. Easily done, isn't
> it? ;-)
Don't get me started! :->)
Seriously, a mode is a propensity to vibrate. There's no wave or resonance
until the mode is excited. Sort of like an EQ set to a narrow boost, but
with the power switch turned off. I'd say with no signal rather than turned
off, except the residual input noise is a signal so there's still some
resonance. Versus a room mode that is silent until something in the room
makes a sound at or near the mode's frequency.
--Ethan
Don Pearce
But they lack the vital central component of resonance - energy
storage in two complementary forms, with periodic transfer between
those two forms. Springs and masses do this between kinetic and
potential energy. Electronic circuits do it between magnetic and
electric fields. Rooms do it (in Helmholz resonator mode) the same way
as springs and masses.
But modes don't do this. All that happens is that waves travelling in
two directions will add in some places and cancel in others. So the
biggest "gain" you can see is 3dB at any point, while dips can
approach infinity. This is radically different behaviour from
resonance. For example, there is no meaningful Q factor associated
with a mode.
If you want to simulate modes with eq, don't set for narrow boost -
that is entirely the wrong thing. Set for narrow cut, with several
dips at harmonically related frequencies.
I could go on, but I won't. I'm sure you can see what I'm getting at.
Mark Zenier
Jose <teac...@aol.nospam.com> wrote:
>> Was that their claim? I would find it hard to believe too.
>
>>> They said that the FAA had detected signal leakage from their cable
>and they had to replace it!
>
>I bet he meant FCC. :)
No, the FAA has (or hires) a bunch of airplanes that fly around
and test their radio navigation systems. So, they're usually the
first outfit to find leakage. And they have no tolerance. Cable
TV uses some of these frequencies on the condition that their system
doesn't cause problems.
The FCC usually waits until the licensed user of a frequency complains.
Mark Zenier mze...@eskimo.com
Googleproofaddress(account:mzenier provider:eskimo domain:com)
Ethan Winer
> But they [modes] lack the vital central component of resonance - energy
> storage in two complementary forms, with periodic transfer between those
> two forms. Springs and masses do this between kinetic and potential
> energy. Electronic circuits do it between magnetic and electric fields.
> Rooms do it (in Helmholz resonator mode) the same way as springs and
> masses. But modes don't do this.
Not sure where you draw the line between "rooms" and "modes." A room does
resonate. In that case it seems to me the air is both the mass and the
spring.
> All that happens is that waves travelling in two directions will add in
> some places and cancel in others. So the biggest "gain" you can see is 3dB
> at any point, while dips can approach infinity.
You can DEFINITELY have peaks larger than 3 dB. First, a single reflection
off a boundary (comb filter) gives a 6 dB peak, not 3 dB. But in a real room
multiple reflections from multiple boundaries can combine to give a total
peak larger than 6 dB. Since the response in a smallish room varies
dramatically over distances as small as a few inches, even at very low
frequencies, it's tough to say for sure where a peak ends and a null begins.
> If you want to simulate modes with eq, don't set for narrow boost - that
> is entirely the wrong thing. Set for narrow cut, with several dips at
> harmonically related frequencies. I could go on, but I won't. I'm sure you
> can see what I'm getting at.
Actually, I don't see what you're getting at. Room modes, when excited, are
like an EQ boost with a fairly high Q. This is easily seen in waterfall
plots such as this one:
http://www.realtraps.com/art_etf2.gif
--Ethan
Don Pearce
dot com> wrote:
>Don,
>
>> But they [modes] lack the vital central component of resonance - energy
>> storage in two complementary forms, with periodic transfer between those
>> two forms. Springs and masses do this between kinetic and potential
>> energy. Electronic circuits do it between magnetic and electric fields.
>> Rooms do it (in Helmholz resonator mode) the same way as springs and
>> masses. But modes don't do this.
>
>Not sure where you draw the line between "rooms" and "modes." A room does
>resonate. In that case it seems to me the air is both the mass and the
>spring.
>
I'm talking about a Helmholz resonance, where the mass of air in - say
- a doorway moves in and out of the room, using the air inside the
room as a spring. When the air is all the way in or out, the energy is
held in the compression. When the air is moving, the energy is held in
the movement. That IS a resonance - it has the two energy-swapping
phases.
>> All that happens is that waves travelling in two directions will add in
>> some places and cancel in others. So the biggest "gain" you can see is 3dB
>> at any point, while dips can approach infinity.
>
>You can DEFINITELY have peaks larger than 3 dB. First, a single reflection
>off a boundary (comb filter) gives a 6 dB peak, not 3 dB. But in a real room
>multiple reflections from multiple boundaries can combine to give a total
>peak larger than 6 dB. Since the response in a smallish room varies
>dramatically over distances as small as a few inches, even at very low
>frequencies, it's tough to say for sure where a peak ends and a null begins.
>
You are right, my maths was all over the place. But the peaks are
never sharp. Nulls, on the other hand are incredibly sensitive to
position. This because they are caused by phase cancellations. The
peaks are simply phase additions. There is no energy storage going on
- hence no resonance.
>> If you want to simulate modes with eq, don't set for narrow boost - that
>> is entirely the wrong thing. Set for narrow cut, with several dips at
>> harmonically related frequencies. I could go on, but I won't. I'm sure you
>> can see what I'm getting at.
>
>Actually, I don't see what you're getting at. Room modes, when excited, are
>like an EQ boost with a fairly high Q. This is easily seen in waterfall
>plots such as this one:
>
>http://www.realtraps.com/art_etf2.gif
>
I see why you would conclude that, but high Q is not what is going on
there. They look peaky simply because they are close together. The
important part of this, though is really the places where
cancellations occur, not the reinforcements.
Look, you have a really good video on comb filtering and how it
happens, and why it happens. This is simply a limit case of that
phenomenon. You only confuse things when you try to describe it as a
resonance.
Michael A. Terrell
>
> > Was that their claim? I would find it hard to believe too.
>
> >> They said that the FAA had detected signal leakage from their cable and they had to replace it!
>
> I bet he meant FCC. :)
Would you care to lay big money on it? Several "Midband" CATV
channels are on the standard aircraft frequencies, and the allowable
leakage levels are quite low. IOW, if a pilot or control tower detects
the signal you have to fix it, or shut those channels down. A lot of
systems already use the "Sniffer", or similar systems in their trucks to
look for leakage while doing routine work. A modulated carrier is
injected at the headend, usually just above the top channel. The
receiver has a preset squelch, and opens at a very low level. The
sniffer had a very irritating audio modulation that couldn't be confused
with any other source.
The required "proof of performance" tests include RF leakage, hum,
noise, and a number of their signal quality tests.
--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.
Michael A. Terrell
Central Florida
Michael A. Terrell
>
> On Jun 28, "Ethan Winer" <ethanw at ethanwiner dot com> wrote:
> > > Hippie fucks like you have even fewer answers,
> > >and produce _zero_ working technology.
> >
> > LOL, that's a great come-back. It kills me when "believers"
> > diss real science, but of course they have nothing of
> > their own to show.
>
> Dudes, it pains me to be the bearer of bad news,
> but you are thick witted bastards.
>
> No offense intended.
Anyone who has to use "Dudes" in a rebuttal has zero credibility.
Ethan Winer
> I'm talking about a Helmholz resonance, where the mass of air in - say
> - a doorway moves in and out of the room, using the air inside the
> room as a spring. When the air is all the way in or out, the energy is
> held in the compression. When the air is moving, the energy is held in
> the movement. That IS a resonance - it has the two energy-swapping
> phases.
Yes, agreed.
> You are right, my maths was all over the place. But the peaks are
> never sharp. Nulls, on the other hand are incredibly sensitive to
> position. This because they are caused by phase cancellations. The
> peaks are simply phase additions. There is no energy storage going on
> - hence no resonance.
Look at the GIF file I linked to again and tell me those peaks are not
sharp! Then look at the ringing trails and tell me there's no resonance.
Yes, there is resonance, and it's due to the wall-wall (or floor-ceiling)
spacing reinforcing a wave repeatedly. It's easy to calculate the frequency
of the resonance from the spacing between boundaries.
> I see why you would conclude that, but high Q is not what is going on
> there. They look peaky simply because they are close together. The
> important part of this, though is really the places where
> cancellations occur, not the reinforcements.
I think both are important. A resonant peak that sustains bass frequencies
makes a muddy mess of bass notes, as some notes linger and mask subsequent
notes. Resonant peaks also impart their frequency onto nearby bass notes
that excite them, often making bass notes sound out of tune even when
they're not. That is, if a room has a strong resonance at 112 Hz, every A
bass note will sound sharp in that room.
I do agree that nulls are a big problem too, and probably worse than nulls.
The most common room acoustics problem I hear is from people who make a mix
that sounds great, then they play it in their car or somewhere else and the
bass is greatly exaggerated. This is because there's always one or more deep
nulls at the mix position, somewhere between 80 and 150 Hz, so when mixing
the person adds too much bass EQ to compensate.
--Ethan
Don Pearce
dot com> wrote:
>Don,
>
>> I'm talking about a Helmholz resonance, where the mass of air in - say
>> - a doorway moves in and out of the room, using the air inside the
>> room as a spring. When the air is all the way in or out, the energy is
>> held in the compression. When the air is moving, the energy is held in
>> the movement. That IS a resonance - it has the two energy-swapping
>> phases.
>
>Yes, agreed.
>
>> You are right, my maths was all over the place. But the peaks are
>> never sharp. Nulls, on the other hand are incredibly sensitive to
>> position. This because they are caused by phase cancellations. The
>> peaks are simply phase additions. There is no energy storage going on
>> - hence no resonance.
>
>Look at the GIF file I linked to again and tell me those peaks are not
>sharp! Then look at the ringing trails and tell me there's no resonance.
>Yes, there is resonance, and it's due to the wall-wall (or floor-ceiling)
>spacing reinforcing a wave repeatedly. It's easy to calculate the frequency
>of the resonance from the spacing between boundaries.
>
No, that truly isn't resonance - it is reverberation, which is an
entirely different thing. The reverberation is reinforced at certain
frequencies because things are arriving in phase. I promise you this
is an entirely different phenomenon to resonance. The tails are not Q
related - you are witnessing mode collapse. And unlike Q, you can't
rely on them to collapse at a given rate - measure ten times, and you
will get ten different answers.
>> I see why you would conclude that, but high Q is not what is going on
>> there. They look peaky simply because they are close together. The
>> important part of this, though is really the places where
>> cancellations occur, not the reinforcements.
>
>I think both are important. A resonant peak that sustains bass frequencies
>makes a muddy mess of bass notes, as some notes linger and mask subsequent
>notes. Resonant peaks also impart their frequency onto nearby bass notes
>that excite them, often making bass notes sound out of tune even when
>they're not. That is, if a room has a strong resonance at 112 Hz, every A
>bass note will sound sharp in that room.
>
But what do you mean by a room having a resonant peak at 112Hz? Move a
couple of feet and you won't hear the note at all.
>I do agree that nulls are a big problem too, and probably worse than nulls.
>The most common room acoustics problem I hear is from people who make a mix
>that sounds great, then they play it in their car or somewhere else and the
>bass is greatly exaggerated. This is because there's always one or more deep
>nulls at the mix position, somewhere between 80 and 150 Hz, so when mixing
>the person adds too much bass EQ to compensate.
>
Nulls are a disaster in a mixing room. You find yourself winding up
the eq to hear a note at proper volume, then when you play it
somewhere else you end up with the cones hanging out of the bass
speakers. At the very least you need to be pushing your chair back and
forth to hear what is really there.
Ethan Winer
> No, that truly isn't resonance - it is reverberation, which is an entirely
> different thing. The reverberation is reinforced at certain frequencies
> because things are arriving in phase. I promise you this is an entirely
> different phenomenon to resonance.
I promise you are simply wrong on this point. :->)
Small rooms don't even have true reverberation. Real reverb builds over
time, but small rooms have a collection of individual reflections with
each decaying quickly. Small rooms also have modal ringing, which is the
resonance I keep referring to. Google "room resonance" if you don't believe
me. This is Physics 101 so I'm really surprised to see you dispute that
rooms resonate!
> The tails are not Q related - you are witnessing mode collapse. And unlike
> Q, you can't rely on them to collapse at a given rate - measure ten times,
> and you will get ten different answers.
They ARE related to Q. As bass traps are added to a room, three things
happen to the modes as observed in a waterfall chart:
1) The ringing times are shortened.
2) The mode Qs are lowered.
3) The mode frequencies shift down in frequency slightly.
The link between 1 and 2 above indicates resonance. Here's a pair of graphs
for the same room I linked above, and these show the room with and without
bass traps:
www.ethanwiner.com/misc-content/lab-ringing-both.gif
You can clearly see all three of the above parameters change.
> Nulls are a disaster in a mixing room. You find yourself winding up the eq
> to hear a note at proper volume, then when you play it somewhere else you
> end up with the cones hanging out of the bass speakers. At the very least
> you need to be pushing your chair back and forth to hear what is really
> there.
Exactly.
--Ethan
Don Pearce
dot com> wrote:
>> The tails are not Q related - you are witnessing mode collapse. And unlike
>> Q, you can't rely on them to collapse at a given rate - measure ten times,
>> and you will get ten different answers.
>
>They ARE related to Q. As bass traps are added to a room, three things
>happen to the modes as observed in a waterfall chart:
>
>1) The ringing times are shortened.
>2) The mode Qs are lowered.
>3) The mode frequencies shift down in frequency slightly.
>
>The link between 1 and 2 above indicates resonance. Here's a pair of graphs
>for the same room I linked above, and these show the room with and without
>bass traps:
>
>www.ethanwiner.com/misc-content/lab-ringing-both.gif
>
>You can clearly see all three of the above parameters change.
In those graphs I see exactly what I expected to see. The modes
collapse more quickly because there isn't so much energy returned into
them by the walls. But because there is no energy transduction - it
remains solely in the wave - there is no resonance.
The big effect is on the nulls - the peaks flatten out in consequence
of the nulls filling in.
The frequency drops slightly because the room is effectively
lengthened by the presence of an absorber, in which the speed of sound
is reduced.
Here's a thing I'd like you to discuss. Comb filtering. If you plot
the frequency response of a speaker close to a wall, positioned as in
your comb filtering demo, it exhibits peaks and dips in the frequency
response because at some frequencies the waves add, and at others they
cancel. Do you regard the high spot between those dips as a resonance,
with a Q, and all the usual good resonant stuff?
Your answer to that will tell me if there is any chance that we can
agree on the rest.
dpi...@cartchunk.org
> On Sun, 8 Jul 2007 12:33:14 -0400, "Ethan Winer" <ethanw at ethanwiner
> the frequency response of a speaker close to a wall, positioned as in
> your comb filtering demo, it exhibits peaks and dips in the frequency
> response because at some frequencies the waves add, and at others they
> cancel. Do you regard the high spot between those dips as a resonance,
> with a Q, and all the usual good resonant stuff?
>
> Your answer to that will tell me if there is any chance that we can
> agree on the rest.
Let's make the experiment even simpler. Consider a system
which has two signal paths through it: One path is direct,
the other path is delayed by 0.2 milliseconds and has a
6 kHz low-pass filter with a slope of 48 dB/octave. The
outputs of these two paths are summed linearly into
a single output.
Now, consider a second system, which consists of a
linear path with a single series circuit consisting of a
an inductor and a capacitor whose values are such
that the value of 1/sqrt(L*C) is about 16,000 radians
per second.
On examining the frequency response of either system,
they exhibit a flat response up about 5 kHz, where there
is a sharp null, and then they are essentially flat above
that frequency.
Question: As they can exhibit essentially identical
frequency response, are they both resonant systems?
Why or why not?
Randy Yates
Depends on how "resonant system" is defined. From what
I've seen, it usually means that there is an equilibrium of
energy transfer between inductive and capacitive elements
(in the case of electronic resonance), so the former system
you proposed doesn't quality as it doesn't necessarily have
both types of elements.
--
% Randy Yates % "She tells me that she likes me very much,
%% Fuquay-Varina, NC % but when I try to touch, she makes it
%%% 919-577-9882 % all too clear."
%%%% <ya...@ieee.org> % 'Yours Truly, 2095', *Time*, ELO
http://home.earthlink.net/~yatescr
Don Pearce
wrote:
You've got it (just leave out the word "necessarily"). And of course
the transfer doesn't have to be between inductance and capacitance,
just two orthogonal energy forms. In the case of a genuine room
resonance it is between pressure and kinetic energy. In a mode we just
have waves summing and cancelling - so no resonance.
dpi...@cartchunk.org
And that is precisely the point of the excercise. Here we
have two linear systems which show essentially the
same properties in the magnitude frequency response.
Are they both resonant systems? To answer that question
requires the person answering it to come up with a definition
of "resonant" which fits both systems.
>From what
> I've seen, it usually means that there is an equilibrium of
> energy transfer between inductive and capacitive elements
> (in the case of electronic resonance), so the former system
> you proposed doesn't quality as it doesn't necessarily have
> both types of elements.
Under that definition, I would agree. But a number of people
bandy about the term "resonance" without knowing, caring or
revealing what that means. The original poster in this thread
and the article he is citing are two example of all three: the
article cited doesn't have a clue what "resonance" means,
doesn't reveal it and doesn't care. It merely sounds cool
and sort kinda scientific in a stupid sort of way.
By the way, as I am sure you know, the two systems I
describe DO have a fundamental difference that's
unambiguous and completely, objectively measurable.
That difference may or may not make one resonant and
the other not, because, again, that requires the person
bandying about the term to define it.
Ethan Winer
> In those graphs I see exactly what I expected to see. The modes collapse
> more quickly because there isn't so much energy returned into them by the
> walls.
Yes.
> The frequency drops slightly because the room is effectively lengthened by
> the presence of an absorber, in which the speed of sound is reduced.
Yes again.
> But because there is no energy transduction - it remains solely in the
> wave - there is no resonance.
I have no idea what transduction is supposed to mean in this context. But
room modes do indeed resonate. :->)
Here's how I distinguish resonance from not resonance: Excite a circuit or
room or whatever with a single step impulse. If the result is a sine wave
having a non-zero duration, you have a resonance. Therefore...
> Comb filtering ... Do you regard the high spot between those dips as a
> resonance, with a Q, and all the usual good resonant stuff?
No. This is an increase in amplitude, but the result signal does not
continue after the source signal stops.
--Ethan
Ethan Winer
> a number of people bandy about the term "resonance" without knowing,
> caring or revealing what that means. The original poster in this thread
> and the article he is citing are two example of all three: the article
> cited doesn't have a clue what "resonance" means, doesn't reveal it and
> doesn't care. It merely sounds cool and sort kinda scientific in a stupid
> sort of way.
Bingo. And that's exactly what I objected to as well. These folks kill me
when they at once deride "science" as not having all the answers, then go on
to use scientific sounding mumbo jumbo in an attempt to sound legitimate. I
hear this all the time on radio ads for bogus alternative medicine products.
First they say science doesn't know what they know, then they go on to claim
proof of effectiveness via double-blind tests.
--Ethan
Don Pearce
dot com> wrote:
>Don,
>
>> In those graphs I see exactly what I expected to see. The modes collapse
>> more quickly because there isn't so much energy returned into them by the
>> walls.
>
>Yes.
>
>> The frequency drops slightly because the room is effectively lengthened by
>> the presence of an absorber, in which the speed of sound is reduced.
>
>Yes again.
>
>> But because there is no energy transduction - it remains solely in the
>> wave - there is no resonance.
>
>I have no idea what transduction is supposed to mean in this context. But
>room modes do indeed resonate. :->)
>
Transduction is the change in form of energy from one type to another
(hence transducer).
>Here's how I distinguish resonance from not resonance: Excite a circuit or
>room or whatever with a single step impulse. If the result is a sine wave
>having a non-zero duration, you have a resonance. Therefore...
>
No - any system with a delay in it will do that. Standing waves do it
for this reason.Back and forth across a room is a very appreciable
delay. And of course at each bounce some of the energy in the wave
dissipates, and you see a phenomenon that looks rather like Q in a
resonant system.
>> Comb filtering ... Do you regard the high spot between those dips as a
>> resonance, with a Q, and all the usual good resonant stuff?
>
>No. This is an increase in amplitude, but the result signal does not
>continue after the source signal stops.
>
It does if you bounce it off a couple of walls. This is the problem -
the mode is just the limit condition of comb filtering when the wave
is at right angles to the wall. Nothing new has happened - the
phenomenon is exactly as it was when at an angle; it just gets to do a
few more bounces, is all.
Randy Yates
Ethan,
I believe you're mistaken here. Any causal, non-ideal system (i.e., a
system other than a straight wire) will have a response that continues
for some non-zero amount of time after a sine wave with a frequency
within its passband has been removed.
This can be seen mathematically as the trailing end of the convolution
of the input sine wave with the causal, finite-lengthed impulse
response.
If that's what makes a system resonant (and I don't believe it is),
then most systems could be classified as resonant.
--
% Randy Yates % "Maybe one day I'll feel her cold embrace,
%% Fuquay-Varina, NC % and kiss her interface,
%%% 919-577-9882 % til then, I'll leave her alone."
Arny Krueger
news:1183990753.5...@k79g2000hse.googlegroups.com
> On Jul 8, 9:39 pm, Randy Yates <y...@ieee.org> wrote:
>> dpie...@cartchunk.org writes:
>>> Let's make the experiment even simpler. Consider a
>>> system which has two signal paths through it: One path
>>> is direct, the other path is delayed by 0.2
>>> milliseconds and has a 6 kHz low-pass filter with a
>>> slope of 48 dB/octave. The outputs of these two paths
>>> are summed linearly into
>>> a single output.
>>> Now, consider a second system, which consists of a
>>> linear path with a single series circuit consisting of a
>>> an inductor and a capacitor whose values are such
>>> that the value of 1/sqrt(L*C) is about 16,000 radians
>>> per second.
>>> On examining the frequency response of either system,
>>> they exhibit a flat response up about 5 kHz, where there
>>> is a sharp null, and then they are essentially flat
>>> above that frequency.
AFAIK, the system with delay will produce a null every 6 KHz.
>>> Question: As they can exhibit essentially identical
>>> frequency response, are they both resonant systems?
>>> Why or why not?
We already know this much of the *book* answer - whether one or both are
resonant systems depends on the definition of resonance.
Knee-jerk approach, check the Wikipedia. Right away, we find the Wikipedia
in error, because their definition (from physics) of resonance is:
"In physics, resonance is the tendency of a system to oscillate at maximum
amplitude at a certain frequency. This frequency is known as the system's
resonance frequency. When damping is small, the resonance frequency is
approximately equal to the natural frequency of the system, which is the
frequency of free vibrations."
The obvious flaw in the Wikipedia definition is that oscillation of the
system can be either minimum or maximum at a resonant frequency, for series
and parallel resonant systems respectively. OTOH, both the series and
parallel systems have maximum transfer of energy between the resonant
componants at resonance.
>> Depends on how "resonant system" is defined.
> And that is precisely the point of the excercise. Here we
> have two linear systems which show essentially the
> same properties in the magnitude frequency response.
But not the identical same amplitude or phase response.
> Are they both resonant systems? To answer that question
> requires the person answering it to come up with a
> definition of "resonant" which fits both systems.
Point of order: If we hope to find that one system is resonant and the other
is not, then the definition of resonant must fit one and not the other.
>> From what
>> I've seen, it usually means that there is an equilibrium
>> of energy transfer between inductive and capacitive
>> elements (in the case of electronic resonance), so the
>> former system you proposed doesn't quality as it doesn't
>> necessarily have both types of elements.
That fits my initial thinking.
> Under that definition, I would agree. But a number of
> people bandy about the term "resonance" without knowing,
> caring or revealing what that means.
If you look at the disambiguation entry in Wikipedia for resonance, one
might find people trying to apply one of the other meanings. Again, I'm
compelled to point out that the Wikipedia fails because the existing
defintion is very physical sciences oriented, and does not contain much from
the arts.
For example from the Amercian Heritage Dictionary we have:
"Richness or significance, especially in evoking an association or strong
emotion: "It is home and family that give resonance . . . to life" (George
Gilder). "Israel, gateway to Mecca, is of course a land of religious
resonance and geopolitical significance" (James Wolcott)."
> The original poster
> in this thread and the article he is citing are two
> example of all three: the article cited doesn't have a
> clue what "resonance" means, doesn't reveal it and
> doesn't care. It merely sounds cool
> and sort kinda scientific in a stupid sort of way.
Or, he's being non-technical and perhaps a little poetic.
dpi...@cartchunk.org
> <dpie...@cartchunk.org> wrote in message
> > On Jul 8, 9:39 pm, Randy Yates <y...@ieee.org> wrote:
> >> dpie...@cartchunk.org writes:
> >>> Let's make the experiment even simpler. Consider a
> >>> system which has two signal paths through it: One path
> >>> is direct, the other path is delayed by 0.2
> >>> milliseconds and has a 6 kHz low-pass filter with a
> >>> slope of 48 dB/octave. The outputs of these two paths
> >>> are summed linearly into
> >>> a single output.
> >>> Now, consider a second system, which consists of a
> >>> linear path with a single series circuit consisting of a
> >>> an inductor and a capacitor whose values are such
> >>> that the value of 1/sqrt(L*C) is about 16,000 radians
> >>> per second.
> >>> On examining the frequency response of either system,
> >>> they exhibit a flat response up about 5 kHz, where there
> >>> is a sharp null, and then they are essentially flat
> >>> above that frequency.
>
> AFAIK, the system with delay will produce a null every 6 KHz.
Not as described above, it won't .
> >>> Question: As they can exhibit essentially identical
> >>> frequency response, are they both resonant systems?
> >>> Why or why not?
>
> We already know this much of the *book* answer - whether
>one or both are resonant systems depends on the definition
>of resonance.
And that's point of the gedanken, to elicit informed opinions
as to which constitutes a "resonant system."
> The obvious flaw in the Wikipedia definition is that oscillation
> of the system can be either minimum or maximum at a resonant
> frequency, for series and parallel resonant systems respectively.
Actually, the definition is not so flawed. In a parallel resonant
tank circuit, impedance is at maximum at resonance, while
in a series resonant tank circuit, admittance is at a maxximum
at resonance. And, respectively, voltage or current is at a
maximum at resonance.
> >> Depends on how "resonant system" is defined.
> > And that is precisely the point of the excercise. Here we
> > have two linear systems which show essentially the
> > same properties in the magnitude frequency response.
>
> But not the identical same amplitude or phase response.
But "identity" itself is insufficient a qualifier. Two
topologically identical circuits could have non-
identical phase and amplitude repsonse: clearly
a trivial example. But two radically different
implementations could have essentially the same
properties in one domain or another and still be
radically different of effectively the same, depending
upon definitions and requirements.
That, again, is the point of the excercise: to determine
what the person means when they use the term
"resonance."
> > Under that definition, I would agree. But a number of
> > people bandy about the term "resonance" without knowing,
> > caring or revealing what that means.
>
> If you look at the disambiguation entry in Wikipedia for resonance, one
> might find people trying to apply one of the other meanings. Again, I'm
> compelled to point out that the Wikipedia fails because the existing
> defintion is very physical sciences oriented, and does not contain much from
> the arts.
What do the arts have to do with it? The current subthread
relates to whether room modes are or are not "resonances."
And, to date, no one has pointed out the very fundamental
difference between the two models I described, which
also have to do fundamentally with the difference between
a conventional second-order periodic energy-exchange
system such as an LRC tank circuit or a Helmholtz contrivance
and a delay system or a room mode, though I know that at
least one other contributor does indeed know the difference.
Ethan Winer
> Transduction is the change in form of energy from one type to another
> (hence transducer).
Gotcha.
> No - any system with a delay in it will do that [continue to ring].
Not so! A reflection off a single boundary, such as one wall of a building
outdoors, will not resonate. Nor is there resonance if you sum a signal with
a delayed version of itself after passing through a simple DDL or three-head
tape recorder etc. (As long as there's no "HELLO...Hello...hello" feedback
used within the delay unit of course.)
> Standing waves do it for this reason.Back and forth across a room is a
> very appreciable delay.
The key here is back and forth. In your previous post you asked:
"If you plot the frequency response of a speaker close
to a wall, positioned as in your comb filtering demo, it
exhibits peaks and dips in the frequency response
because at some frequencies the waves add, and at
others they cancel. Do you regard the high spot between
those dips as a resonance, with a Q, and all the usual
good resonant stuff?"
You said nothing about repeated reflections between two parallel surfaces!
This is the key between resonant peaks and non-resonant peaks.
> It does if you bounce it off a couple of walls.
Again, you can't argue using a moving target. :->)
> This is the problem - the mode is just the limit condition of comb
> filtering when the wave is at right angles to the wall.
This brings up an interesting point. I consider comb filtering - more
properly, acoustic interference - as the parent property, with modes and
resonances and flutter echo et all as subsets. I thought I was alone in this
thinking because I've had many self proclaimed "expert" acousticians tell me
I'm full of crap and that modes define everything. But modes and resonances
are a more complex subset of simple interference, as you correctly stated.
So do we agree yet? :->)
--Ethan
Ethan Winer
> Any causal, non-ideal system (i.e., a system other than a straight wire)
> will have a response that continues for some non-zero amount of time after
> a sine wave with a frequency within its passband has been removed.
Okay, if you have a REALLY long piece of wire I'm sure the reactive L and C
components can become a factor. But those are second-order effects, and in
most cases the frequencies involved are well beyond the audible range. I
think engineers call that stuff parasitic, yes? In a practical examination
of what (I thought) we're discussing, a single reflection combined with the
original source is not resonant.
--Ethan
Randy Yates
You misunderstood me - I was saying any system OTHER THAN a wire. I
mean that if you take a system like an op-amp network with resistors
and capacitors and specific bandwidth, or something like a speaker
crossover, THOSE types of systems would be resonant according to your
definition.
Of course a wire is pretty much a Dirac delta function impulse
response (no transients to speak of).
--
% Randy Yates % "Midnight, on the water...
%% Fuquay-Varina, NC % I saw... the ocean's daughter."
%%% 919-577-9882 % 'Can't Get It Out Of My Head'
%%%% <ya...@ieee.org> % *El Dorado*, Electric Light Orchestra
http://home.earthlink.net/~yatescr
dpi...@cartchunk.org
> "Ethan Winer" <ethanw at ethanwiner dot com> writes:
>
> > Randy,
>
> >> Any causal, non-ideal system (i.e., a system other than a straight
> >> wire) will have a response that continues for some non-zero amount
> >> of time after a sine wave with a frequency within its passband has
> >> been removed.
>
> > Okay, if you have a REALLY long piece of wire I'm sure the reactive L
> > and C components can become a factor. But those are second-order
> > effects, and in most cases the frequencies involved are well beyond
> > the audible range. I think engineers call that stuff parasitic, yes?
> > In a practical examination of what (I thought) we're discussing, a
> > single reflection combined with the original source is not resonant.
>
> You misunderstood me - I was saying any system OTHER THAN a wire. I
> mean that if you take a system like an op-amp network with resistors
> and capacitors and specific bandwidth, or something like a speaker
> crossover, THOSE types of systems would be resonant according to your
> definition.
To amplify Randy's point, consider a current state of
the art analog-digital-analog conversion system, nothing
more complicated than a high-quality sound card in
a computer set up in straight pass-through mode. Hit
it with an impulse, and it WILL ring for not an inconsiderable
time after the impulse is done. Is it resonating? According
to ONE of Winer's definitions, it is, but according to
another, the existence of some measurable peak or
dip in the amplitude vs frequency response, it is not:
the response over the bandwidth is dead nuts flat,
within a very small fraction of a dB, and the phase
response is essentially perfect over the bandwidth.
Take a very high quality professional analog tape recorder
(say a Studer) running 30 ips, adjusted for the flattest
frequency response over the bandwidth (on such a
machine, I'd expect to make to 25 kHz +-1dB at all
reasonable recording levels). The output WILL ring
for a significant number of cycles. Is it a resonant
system?
And all of these system will show a decay tail if hit
with a sine wave tone burst.
Build yourself a 4th order butterworth low-pass filter,
and hit it with an impulse, and watch the output ring:
is it resonant (trick question, because i forgot to tell
you you aren't allowed to build it out of components
like inductors and capacitors).
Are these system resonant?
Arny Krueger
<dpi...@cartchunk.org> wrote in message
news:1184076074.2...@22g2000hsm.googlegroups.com...
> On Jul 10, 9:01 am, "Arny Krueger" <a...@hotpop.com> wrote:
>> <dpie...@cartchunk.org> wrote in message
>> > On Jul 8, 9:39 pm, Randy Yates <y...@ieee.org> wrote:
>> >> dpie...@cartchunk.org writes:
>> >>> Let's make the experiment even simpler. Consider a
>> >>> system which has two signal paths through it: One path
>> >>> is direct, the other path is delayed by 0.2
>> >>> milliseconds and has a 6 kHz low-pass filter with a
>> >>> slope of 48 dB/octave. The outputs of these two paths
>> >>> are summed linearly into
>> >>> a single output.
>> >>> Now, consider a second system, which consists of a
>> >>> linear path with a single series circuit consisting of a
>> >>> an inductor and a capacitor whose values are such
>> >>> that the value of 1/sqrt(L*C) is about 16,000 radians
>> >>> per second.
>> >>> On examining the frequency response of either system,
>> >>> they exhibit a flat response up about 5 kHz, where there
>> >>> is a sharp null, and then they are essentially flat
>> >>> above that frequency.
>>
>> AFAIK, the system with delay will produce a null every 6 KHz.
>
> Not as described above, it won't .
Oh, I missed the tricky 6 KHz low pass filter.
>> >>> Question: As they can exhibit essentially identical
>> >>> frequency response, are they both resonant systems?
>> >>> Why or why not?
>>
>> We already know this much of the *book* answer - whether
>>one or both are resonant systems depends on the definition
>>of resonance.
> And that's point of the gedanken, to elicit informed opinions
> as to which constitutes a "resonant system."
Both.
>> The obvious flaw in the Wikipedia definition is that oscillation
>> of the system can be either minimum or maximum at a resonant
>> frequency, for series and parallel resonant systems respectively.
> Actually, the definition is not so flawed. In a parallel resonant
> tank circuit, impedance is at maximum at resonance, while
> in a series resonant tank circuit, admittance is at a maxximum
> at resonance. And, respectively, voltage or current is at a
> maximum at resonance.
Or, one has maximum current amplitude, while the other has maximum voltage
amplitude.
>> >> Depends on how "resonant system" is defined.
>> > And that is precisely the point of the excercise. Here we
>> > have two linear systems which show essentially the
>> > same properties in the magnitude frequency response.
>> But not the identical same amplitude or phase response.
One is minumum phase, the other is not.
> But "identity" itself is insufficient a qualifier. Two
> topologically identical circuits could have non-
> identical phase and amplitude repsonse: clearly
> a trivial example. But two radically different
> implementations could have essentially the same
> properties in one domain or another and still be
> radically different of effectively the same, depending
> upon definitions and requirements.
Thus they are both resonances.
> That, again, is the point of the excercise: to determine
> what the person means when they use the term
> "resonance."
>> > Under that definition, I would agree. But a number of
>> > people bandy about the term "resonance" without knowing,
>> > caring or revealing what that means.
>
>> If you look at the disambiguation entry in Wikipedia for resonance, one
>> might find people trying to apply one of the other meanings. Again, I'm
>> compelled to point out that the Wikipedia fails because the existing
>> defintion is very physical sciences oriented, and does not contain much
>> from
>> the arts.
> What do the arts have to do with it?
The point being that a person with a stronger background in the arts will
define resonance one way, while a person with a stronger background in the
sciences will define resonance in another.
> The current subthread
> relates to whether room modes are or are not "resonances."
Room modes are resonances. They are acoustical, so the acoustical space that
they take place in is signficant.
> And, to date, no one has pointed out the very fundamental
> difference between the two models I described, which
> also have to do fundamentally with the difference between
> a conventional second-order periodic energy-exchange
> system such as an LRC tank circuit or a Helmholtz contrivance
> and a delay system or a room mode,
Minimum phase versus non minimum phase comes to my mind first.
z
> http://www.wineenhancer.net/wine-accessories-supplies-how.asp
>
> "Our trade secret, proprietary design creates a
> harmonically balanced resonate frequency that
> affects the water molecules structure"
>
> Proving, again, that science doesn't have all the answers...
>
> --
> Rich
I find that after drinking the first glass, the wine all by itself
becomes smoother and brighter with longer finish and less burn,
astringency, and chalky feeling on tongue.
z
> > Was that their claim? I would find it hard to believe too.
> >> They said that the FAA had detected signal leakage from their cable and they had to replace it!
>
> I bet he meant FCC. :)
Or AA.
z
> Even maths doesn't deal in facts. All proofs rest on axioms - which
> are pretty good assumptions about how the world works, but they are
> just assumptions. So a proof will really read "Such and such is
> proven, assuming that...".
Well, that gets us back to Godel, Escher, Bach; Turing machines which
never reach the end; etc.
Max Hauser
"Mike Tommasi" in news:5et8q8F...@mid.individual.net...
> Max Hauser wrote:
>> ...
>> On the other hand, a recent conversation with someone who
>> had something to do with the history of newsgroups illuminated
>> another angle that I thought I'd mention. My informant
>> described an experiment years ago. A popular newsgroup ... was converted
>> to moderated form. ...
>> An effort was made to keep all irrelevant chat out of the new
>> moderated newsgroup. But the organizers found that a certain
>> proportion of chat is necessary to sustain interest. Even people
>> who'd supported moderation would drift away, otherwise. Just food for
>> thought. -- Max
>
> Yes, I enjoyed the exchange between Mark and Don. ;-)
>
> The difference between audio geeks and wine geeks is that wine geeks do
> not believe the hocus pocus stuff, audio geeks do. ...
>
> Mike (former member of the Audio Engineering Society)
Sorry to tell you, Mike, but we _all_ harbor some notions contrary to fact.
It seems part of how the mind works. (Various wise people have marveled
less at how much they do or don't know, than at the things they do know that
aren't so.)
I see hocus-pocus among some wine geeks, just like some audio geeks. For
instance, mythologies on wine-writing history. Not to mention all that
business about magnets (prompting a section in alt.food.wine's FAQ file).
I used to post on audio technologies -- just technical questions, in areas I
knew something about. Example from 1991-- this one was popular -- posted
after some people were furious and another claimed they'd be damned if
something was true (it was):
(If that European archive fails, find others by searching word combo
oversampling+curious+furious+damned .)
Also no matter how clear-cut the subject matter, hecklers can be relied on,
as the night follows the day, to attack any information they don't happen to
like. (Again, how the mind works.) I've seen it with postings on consumer
technologies, language history, internet history, absinthe, truffles, the
AxR-1 vine rootstock debacle, wine literature, even the simple math of
multiplying by -1. These hecklers don't always give the impression they are
used to dealing much with things like sources and evidence and facts
unaffected by what you think. But they don't let such limitations restrain
them!
Max (longtime member of Audio Engineering Society)
Stephen J. Rush
And it usually gets even better with the next bottle. It would be really
interesting to transfer some outrageously expensive wine into screw-top
bottles and serve it to a party of wine snobs. Have there ever been any
double-blind tests?
Mr.T
"Mike Tommasi" <nob...@tommasi.org> wrote in message
news:5fjeteF...@mid.individual.net...
> You are right of course... but wine geeks who believe in pyramids and
> magnets tends to be on the fringe and so their problem can be seen as a
> superstition on a par with astrology, while it seems to me that audio
> exotica enjoys a higher status more akin to religion. ;-)
Not IMO. I would place audio superstition on the same level as astrology,
numerology, feng shui, etc etc.
Religion is far more widespread and far more insidious.
MrT.
Mr.T
"Stephen J. Rush" <sjr...@comcast.net> wrote in message
news:Y-mdnfg_VJGkiwnb...@comcast.com...
> And it usually gets even better with the next bottle. It would be really
> interesting to transfer some outrageously expensive wine into screw-top
> bottles and serve it to a party of wine snobs. Have there ever been any
> double-blind tests?
In fact most, if not all, wine judging is at least single blind, and usually
double blind.
And wine judges spit it out to prevent the wine tasting better the drunker
they get.
But it's still only a collection of opinions!
MrT.
Ethan Winer
> Are these system resonant?
I don't care anymore. :->)
Seriously, the original issue was whether a room mode is a resonance. Well,
actually, the original issue was whether a magic resonator can improve the
taste of wine. :->) But THEN it became whether room modes are resonances.
And they most certainly are by every definition I'm aware of.
--Ethan
Mark Lipton
>
> And it usually gets even better with the next bottle. It would be really
> interesting to transfer some outrageously expensive wine into screw-top
> bottles and serve it to a party of wine snobs. Have there ever been any
> double-blind tests?
All the time. Almost all serious judging of wine is done under single-
or double-blind conditions. And, yes, there are some surprises, such as
Two Buck Chuck Chardonnay recently winning a prestigious California wine
competition, but far more often than not "the usual suspects" do very
well in single- and double-blind conditions. It's (usually) not without
reason that famous wines become famous, though one of the fascinating
things about wine is that each year is a different story. And why do
you think that you can't get good wine in a screwcapped bottle? Some
very fine wines are bottled under screwcap, and many winegeeks applaud
the move.
Mark Lipton
--
alt.food.wine FAQ: http://winefaq.hostexcellence.com
z
> "Stephen J. Rush" <sjr...@comcast.net> wrote in messagenews:Y-mdnfg_VJGkiwnb...@comcast.com...
>From what I read, wine tasting is surprisingly repeatable, both with
one taster doing repeated tests, and between different tasters. Highly
UNLIKE audio testing.
Ian Iveson
>> You are right of course... but wine geeks who believe in pyramids
>> and
>> magnets tends to be on the fringe and so their problem can be seen
>> as a
>> superstition on a par with astrology, while it seems to me that
>> audio
>> exotica enjoys a higher status more akin to religion. ;-)
>
> Not IMO. I would place audio superstition on the same level as
> astrology,
> numerology, feng shui, etc etc.
> Religion is far more widespread and far more insidious.
More like alchemy. No specific methodology. Groping in the half-light,
hoping to stir up a new science.
A religion is a group of people defending the boundaries of received
wisdom. Science becomes religion when it stops making progress.
Denying the possibility of progress in audio electronics is the
stock-in-trade of the defenders of the reproductionist faith. Now
accuracy of reproduction is commonplace their agenda is complete:
there's nothing left to discuss.
That's why the audio forums are dead. They are populated by geeks with
nothing left to say, save to chat about other things and defend
themselves against the New Scientists of the Golden Age.
cheers, Ian
Audiophool.
Max Hauser
> ...
> You are right of course... but wine geeks who believe in pyramids and
(Among the population of audiophiles, I take that to mean.)
> I will not go through all the details, but there are people that seriously
> believe that weighing down a CD will bring less wow and flutter... and
> there are those who claim to hear the difference that an 8 ohm
> transmission line makes... and the latest, someone here in France has come
> up with a filter for those evil AC outlets that brings about a complete
> transformation of the sound output of CD players and amps, it sells for
> €27,000........................................
>
> Mike Tommasi - Six Fours, France
The gadgets with absurd rationalizations and €27,000 price tags are
legitimate gripes. (I could give you more real cases I collected. For an
invited talk about this at a big technical conference. I reported only
examples abject even on their own terms. Like a $10,000 or so preamplifier
that, inside, had only a commonplace audibly dubious amplifier chip selling
for a few cents.)
But the flip side to this is underappreciated in the technical world IMO.
Some of these consumer technologies are rather complex, and skilled
technical people not specifically expert may not perceive or understand
their subtleties. Years of training to model reality with mathematical
abstractions chosen partly for their tractability exacerbates this problem.
You find engineers and scientists arguing from a textbook model for a
reality it doesn't fit.
The original audio newsgroup years (net.audio from 1982, called rec.audio
after late 1986) were a showplace for these behaviors (and audiophile myths
and ideologies). Dick Pierce parodied some behaviors skillfully (from years
working on practical audio) in his classic "Audio anecdote" posting series
that many people enjoyed.
Skin effect in speaker wires is an example. (Tendency of current to flow
near the surface as frequency increases.) Not every engineer knows offhand
that this effect can be electrically important even at audio frequencies,
especially with long runs driving an often complex speaker impedance.
Quantifying skin depth is an undergraduate EM homework problem (links
below). But discussions online (and in my experience, offline too) were
full of offhand technical assertions that skin depth equated to EM
wavelength of the signal, or even to air acoustic wavelength. It's neither,
but people would argue "technically" from either assumption.
An even purer example is multiplying by -1 (known identically in the signal
world as "180-degree phase shift"). In 1991 someone asked online how to do
180-degree phase shift on a sampled audio signal. A few people answered
accurately at once, but were submerged and/or attacked by opinionated,
mutually hostile technical assertions whose sole commonality was to be
unfailingly wrong. (Did you hear the line about a little learning being a
dangerous thing?)
-- Max
Online audio skin-depth note from 20 years ago:
http://tinyurl.com/2m6mas
Arithmetic erratum:
http://tinyurl.com/3yxurt
Mr.T
"Ian Iveson" <IanIves...@blueyonder.co.uk> wrote in message
news:uF8li.4662$jY5....@fe1.news.blueyonder.co.uk...
> Denying the possibility of progress in audio electronics is the
> stock-in-trade of the defenders of the reproductionist faith. Now
> accuracy of reproduction is commonplace their agenda is complete:
> there's nothing left to discuss.
Well if you think speakers are now perfect, recording techniques beyond
reproach, and even room acoustics now universally faultless, then I guess
you would imagine "accuracy of reproduction is commonplace".
The discussion of course would be by the many millions who disagree with
that.
MrT.
Mr.T
"z" <gzuc...@snail-mail.net> wrote in message
news:1184168653.0...@22g2000hsm.googlegroups.com...
> >From what I read, wine tasting is surprisingly repeatable, both with
> one taster doing repeated tests, and between different tasters.
With the same group of tasters, yes. Between a different group of tasters,
not so much.
>Highly UNLIKE audio testing.
Not so different really. Neither group likes to admit their personal
shortcomings.
MrT.
Ian Iveson
>> Denying the possibility of progress in audio electronics is the
>> stock-in-trade of the defenders of the reproductionist faith. Now
>> accuracy of reproduction is commonplace their agenda is complete:
>> there's nothing left to discuss.
>
> Well if you think speakers are now perfect, recording techniques
> beyond
> reproach, and even room acoustics now universally faultless, then I
> guess
> you would imagine "accuracy of reproduction is commonplace".
> The discussion of course would be by the many millions who disagree
> with
> that.
Even if you are right, that's just three areas of legitimate debate,
whereas once there were many.
Commonplace and ubiquitous or universal aren't quite the same. It is
certainly possible to find music and speakers that have been produced
by fools and cheapskates, and played in awkward places by idiots, but
the technology to produce the best, from the point of view of
reproduction, is well known and won't be otherwise for the foreseeable
future. There is no possibility of progress in design.
So gripes about incompetently designed products may continue, but
there still won't be anything new to discuss in the reproductionist
camp. They've done everything they can and are at the end of where
it's got them.
I don't come here often, I should admit, but in audio newsgroups in
general, how often do you see legitimate technical debates? There was
an exception in rec.audio.tubes but now that is dominated by
reproductionists (and a valve oriented reproductionist is daft or
dishonest IMO) genuine discussion has almost disappeared.
The reason I don't come here often, it occurs to me, is encapsulated
in the name of the group. No point here I suppose in asserting that
the key question regarding domestic audio systems is about purpose
rather than execution.
Perhaps the same could be said of science, engineering, economics,
even history. As Gordon Brown pointed out, the role of politicians is
now to serve rather than to lead: when there is nowhere else to go,
there are no reasonable alternatives to consider.
Now we have the engineering, it's time to redevelop the art, I think.
Wrong place to say so...I guess a moderator would have shut me up
before now.
cheers, Ian
Ian Iveson
If the ringing due to the transient response of the system were
excited at one of the frequencies it contains, then the system would
resonate. Resonance is what you get when the input frequency is close
to a mode, no? The mere existence of modes is not enough...
But, like "feedback", it is a term with several degrees of looseness.
cheers, Ian
dpi...@cartchunk.org
wrote:
But none of the systems I described have "modes." None
of them have a resonant frequency. Yet they still "ring"
by one definition being bandied about.
Construct a waveform from the following series:
F(t) = sum 1/n sin(nwt), n = 1, 3, 5, ...
and limit n to some number, oh, maybe 11 or 19.
The resulting waveform rings. Is it resonating?
Does it have modes?
Mr.T
> Commonplace and ubiquitous or universal aren't quite the same. It is
> certainly possible to find music and speakers that have been produced
> by fools and cheapskates, and played in awkward places by idiots, but
> the technology to produce the best, from the point of view of
> reproduction, is well known and won't be otherwise for the foreseeable
> future. There is no possibility of progress in design.
Now that is beyond a bold statement, completely silly I would say.
> So gripes about incompetently designed products may continue, but
> there still won't be anything new to discuss in the reproductionist
> camp. They've done everything they can and are at the end of where
> it's got them.
Sounds like the patent lawer who said 100 years ago that everything that
could be invented, had been :-)
Even $100k speakers have their shortcomings, so I'm not sure why you imagine
those priced at what normal people can afford cannot be improved on?
As technology improves, hopefully we will see the prices get cheaper.
However there is still the not insignificant matter of personal preference,
physical size restraints, and any number of other individual compromises.
> Perhaps the same could be said of science, engineering, economics,
> even history. As Gordon Brown pointed out, the role of politicians is
> now to serve rather than to lead: when there is nowhere else to go,
> there are no reasonable alternatives to consider.
Which is only said by those with no alternative vision of course.
MrT.
Arny Krueger
>> To amplify Randy's point, consider a current state of
>> the art analog-digital-analog conversion system, nothing
>> more complicated than a high-quality sound card in
>> a computer set up in straight pass-through mode. Hit
>> it with an impulse, and it WILL ring for not an
>> inconsiderable time after the impulse is done. Is it
>> resonating?
Could be. Certainly, if you build an analog filter with a cutoff that is
even a fraction as sharp as the one in a modern converter, you'll end up
with a lot of L's and C's. It looks something like a collection of resonant
filters. For example, the CDP 101 used an analog reconstruction filter and a
schematic of it was in the service manual.
>> According to ONE of Winer's definitions, it
>> is, but according to another, the existence of some
>> measurable peak or dip in the amplitude vs frequency response, it is not:
I see a *big* dip, right at the cutoff frequency.
>> the response over the bandwidth is dead nuts flat,
>> within a very small fraction of a dB, and the phase
>> response is essentially perfect over the bandwidth.
Aside from the transition band.
>> Take a very high quality professional analog tape
>> recorder (say a Studer) running 30 ips, adjusted for the
>> flattest frequency response over the bandwidth (on such a
>> machine, I'd expect to make to 25 kHz +-1dB at all
>> reasonable recording levels). The output WILL ring
>> for a significant number of cycles. Is it a resonant
>> system?
There are no doubt some resonant circuits in the circuit. Some may even be
resonating in the bandpass. My recollection is that the final low pass
filter is based on what's happening in the tape head gap, which approximates
a filter based on delays.
>> And all of these system will show a decay tail if hit
>> with a sine wave tone burst.
Often high quality analog tape recorders do things to midrange square waves
that are pretty nasty looking. People who wince at the minor damage that
44 KHz sampling does should go ballistic.
>> Build yourself a 4th order butterworth low-pass filter,
>> and hit it with an impulse, and watch the output ring:
>> is it resonant (trick question, because i forgot to tell
>> you you aren't allowed to build it out of components
>> like inductors and capacitors).
>> Are these system resonant?
In some ways.
> If the ringing due to the transient response of the
> system were excited at one of the frequencies it
> contains, then the system would resonate. Resonance is
> what you get when the input frequency is close to a mode,
> no? The mere existence of modes is not enough...
> But, like "feedback", it is a term with several degrees
> of looseness.
IIRs seem to have internal energy exchanges that seem to harken back to
simple LC circuits.
Arny Krueger
news:4696df39$0$30511$afc3...@news.optusnet.com.au
> "Ian Iveson" <IanIves...@blueyonder.co.uk> wrote in
> message
> news:B8uli.5384$iE5....@fe3.news.blueyonder.co.uk...
>> Commonplace and ubiquitous or universal aren't quite the
>> same. It is certainly possible to find music and
>> speakers that have been produced by fools and
>> cheapskates, and played in awkward places by idiots, but
>> the technology to produce the best, from the point of
>> view of reproduction, is well known and won't be
>> otherwise for the foreseeable future. There is no
>> possibility of progress in design.
>
> Now that is beyond a bold statement, completely silly I
> would say.
Agreed.
>> So gripes about incompetently designed products may
>> continue, but there still won't be anything new to
>> discuss in the reproductionist camp. They've done
>> everything they can and are at the end of where it's got
>> them.
We are far from doing everything we can or need to do in the acoustic
domain. In some ways, we are just starting out.
> Sounds like the patent lawer who said 100 years ago that
> everything that could be invented, had been :-)
> Even $100k speakers have their shortcomings, so I'm not
> sure why you imagine those priced at what normal people
> can afford cannot be improved on?
Good point.
> As technology improves, hopefully we will see the prices
> get cheaper. However there is still the not insignificant
> matter of personal preference, physical size restraints,
> and any number of other individual compromises.
IME preference predominates when practical perfection is elusive. The
natural enemy of preference is practical perfection.
Example: Phono cartridges versus CD players. For a long time phono
cartrdiges were pathetic things that as a rule were far from being
practically perfect. Near the end of the vinyl era, cartridges got to be
pretty good, and people often made choices based on other things than their
preferences in say bass and treble balance. However, CD players started out
very good and only got better and cheaper. A/Bing CD players has been a very
boring pastime for about 2 decades.
>> Perhaps the same could be said of science, engineering,
>> economics, even history. As Gordon Brown pointed out,
>> the role of politicians is now to serve rather than to
>> lead: when there is nowhere else to go, there are no
>> reasonable alternatives to consider.
> Which is only said by those with no alternative vision of
> course.
Leadership is still an evolving technology, and one that is very relevant to
politics.
Ethan Winer
> Often high quality analog tape recorders do things to midrange square
> waves that are pretty nasty looking. People who wince at the minor damage
> that 44 KHz sampling does should go ballistic.
LOL, this is why the "analog tape rules" crowd cracks me up. If they'd just
admit it's an effect they find pleasing, I'd be happy and we could go our
separate ways in peace. But no, they argue that analog tape is "better" than
digital recording, and then when they can't back it up with actual science
that resort to name calling. Likewise for vinyl enthusiasts. :->)
--Ethan
Ethan Winer
> If the ringing due to the transient response of the system were excited at
> one of the frequencies it contains, then the system would resonate.
> Resonance is what you get when the input frequency is close to a mode, no?
> The mere existence of modes is not enough...
This is a good distinction. I've heard people argue that modes and standing
waves are the same thing. But they're not. A room mode is merely a
propensity to vibrate, but it's not the actual vibration nor is it a wave of
any type. Mode is short for "mode of vibration," so it describes what WOULD
happen when excited, as you correctly observed.
--Ethan