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.

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.

Mark Lipton
--
alt.food.wine FAQ: http://winefaq.hostexcellence.com

On Mon, 02 Jul 2007 13:55:14 -0400, Mark Lipton >
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.
>
>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.
>
>Mark Lipton

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.

d
--
Pearce Consulting
http://www.pearce.uk.com

Mike Tommasi wrote, early in the thread "New Age wine enhancement":

> 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

In article > ,
Jose > 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
Googleproofaddress(account:mzenier provider:eskimo domain:com)

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! :->)

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

On Tue, 3 Jul 2007 16:13:18 -0400, "Ethan Winer" <ethanw at ethanwiner
dot com> wrote:

>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! :->)
>
>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 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? ;-)

d

--
Pearce Consulting
http://www.pearce.uk.com

Ethan Winer wrote:
> 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.

Mark Lipton

--
alt.food.wine FAQ: http://winefaq.hostexcellence.com

"Ethan Winer" <ethanw at ethanwiner dot com> wrote in message
...
> > 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.

Mark,

> http://en.wikipedia.org/wiki/Nuclear_magnetic_resonance

Okay, thanks.

What's that have to do with wine? :->)

--Ethan

Don,

> 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

On Wed, 4 Jul 2007 11:28:36 -0400, "Ethan Winer" <ethanw at ethanwiner
dot com> wrote:

>Don,
>
>> 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

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.

d

--
Pearce Consulting
http://www.pearce.uk.com

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.

> 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

On Thu, 5 Jul 2007 14:15:32 -0400, "Ethan Winer" <ethanw at ethanwiner
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.

d


--
Pearce Consulting
http://www.pearce.uk.com

Jose 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.


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

RichD wrote:
>
> On Jun 28, "Ethan Winer" <ethanw at ethanwiner dot com> wrote:
> > > Hippie ****s 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 *******s.
>
> No offense intended.


Anyone who has to use "Dudes" in a rebuttal has zero credibility.


--
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

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.

> 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

On Fri, 6 Jul 2007 13:01:24 -0400, "Ethan Winer" <ethanw at ethanwiner
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.

d

--
Pearce Consulting
http://www.pearce.uk.com

Don,

> 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:

http://www.ethanwiner.com/misc-conte...nging-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

On Sun, 8 Jul 2007 12:33:14 -0400, "Ethan Winer" <ethanw at ethanwiner
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:
>
>http://www.ethanwiner.com/misc-conte...nging-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.

d

--
Pearce Consulting
http://www.pearce.uk.com

On Jul 8, 12:51 pm, (Don Pearce) wrote:
> On Sun, 8 Jul 2007 12:33:14 -0400, "Ethan Winer" <ethanw at ethanwiner
> 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.

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?

writes:

> On Jul 8, 12:51 pm, (Don Pearce) wrote:
>> On Sun, 8 Jul 2007 12:33:14 -0400, "Ethan Winer" <ethanw at ethanwiner
>> 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.
>
> 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?

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."
%%%% > % 'Yours Truly, 2095', *Time*, ELO
http://home.earthlink.net/~yatescr

On Sun, 08 Jul 2007 21:39:06 -0400, Randy Yates >
wrote:

writes:
>
>> On Jul 8, 12:51 pm, (Don Pearce) wrote:
>>> On Sun, 8 Jul 2007 12:33:14 -0400, "Ethan Winer" <ethanw at ethanwiner
>>> 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.
>>
>> 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?
>
>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.

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.

d

--
Pearce Consulting
http://www.pearce.uk.com

On Jul 8, 9:39 pm, Randy Yates > wrote:
> writes:
> > On Jul 8, 12:51 pm, (Don Pearce) wrote:
> >> On Sun, 8 Jul 2007 12:33:14 -0400, "Ethan Winer" <ethanw at ethanwiner
> >> 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.
>
> > 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?
>
> 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.
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.

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. :->)

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

> wrote:

> 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

On Mon, 9 Jul 2007 12:12:15 -0400, "Ethan Winer" <ethanw at ethanwiner
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.

d

--
Pearce Consulting
http://www.pearce.uk.com

"Ethan Winer" <ethanw at ethanwiner dot com> writes:

> 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. :->)
>
> 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,

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."
%%%% > % 'Yours Truly, 2095', *Time*, ELO
http://home.earthlink.net/~yatescr

> wrote in message
oups.com
> On Jul 8, 9:39 pm, Randy Yates > wrote:

>> 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.

> 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.

On Jul 10, 9:01 am, "Arny Krueger" > wrote:
> > wrote in message
> > On Jul 8, 9:39 pm, Randy Yates > wrote:
> >> 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.

Don,

> 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

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.

--Ethan

"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.

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'
%%%% > % *El Dorado*, Electric Light Orchestra
http://home.earthlink.net/~yatescr

On Jul 10, 12:45 pm, Randy Yates > wrote:
> "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?

> wrote in message
ups.com...
> On Jul 10, 9:01 am, "Arny Krueger" > wrote:
>> > wrote in message
>> > On Jul 8, 9:39 pm, Randy Yates > wrote:
>> >> 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.

On Jun 28, 3:51 am, RichD > wrote:
> http://www.wineenhancer.net/wine-acc...pplies-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.

On Jul 1, 11:52 pm, Jose > 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.

Or AA.

On Jun 28, 1:25 pm, (Don Pearce) wrote:

> 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.

I expanded this distribution to more of the groups that saw the original.

"Mike Tommasi" in ...
> 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):

http://tinyurl.com/2ska8m

(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)

On Tue, 10 Jul 2007 13:29:03 -0700, z wrote:

> On Jun 28, 3:51 am, RichD > wrote:
>> http://www.wineenhancer.net/wine-acc...pplies-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.

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?

"Mike Tommasi" > wrote in message
...
> 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.