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Bob Cain Goes Down And Out In Defeat

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Anonymous
August 29, 2004 9:44:34 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

The debate is over Bob. Dynamic Doppler distortion exists whether you
care to admit it or not. The only thing that is presently missing is
confirmation of Art Ludwig's theoretical analysis by direct
measurement of Doppler distortion in a tube. That confirmation is
only a week or so away, and is, for all pactical purposes, little more
than icing on the cake. It's time for you to confront and accept
reality and stand up like a man with intetrity and admit that you were
wrong about every aspect of this issue.

More about : bob cain defeat

Anonymous
August 30, 2004 5:38:04 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

"The Ghost" <the_ghostbuster@netzero.com> wrote in message
news:b5fb78ba.0408291644.7ab249b6@posting.google.com...
> The debate is over Bob. Dynamic Doppler distortion exists whether you
> care to admit it or not. The only thing that is presently missing is
> confirmation of Art Ludwig's theoretical analysis by direct
> measurement of Doppler distortion in a tube. That confirmation is
> only a week or so away, and is, for all pactical purposes, little more
> than icing on the cake. It's time for you to confront and accept
> reality and stand up like a man with intetrity and admit that you were
> wrong about every aspect of this issue.

Not so fast, Mr. Ghost. One experiment will not settle the issue, nor will
Art Ludwig's exact solution. They're necessary, but not sufficient. Mr.
Ludwig's solution needs review. The experimental design will require review.
The experiment will need to be independently reproducible, and all results
consistent with Mr. Ludwig's solution. From the looks of it, Doppler
Distortion might be intrinsic to fundamental loudspeaker operation, but it
hasn't reached the status of a physical law just yet.
Anonymous
August 30, 2004 5:38:05 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Karl Uppiano wrote:

> From the looks of it, Doppler
> Distortion might be intrinsic to fundamental loudspeaker operation, but it
> hasn't reached the status of a physical law just yet.

I believe it goes beyond acoustics. Doppler mixing occurs
with _any_ kind of wave propegation where there is frequency
dependant coupling between Tx and Rx. That, at least, is my
conjecture. It is not original. It was one of the short
answers I got to my questions about this for the acoustic
wave case in sci.physics.research a few weeks ago. It was
an epiphany for me because it explains, in principle at
least, every aspect of the phenomenon that has been noted,
including my lesser conjecture that it does not occur with
anything generating plane waves. When that is finally shown
then the frequency dependant coupling conjecture is the only
remaining candidate for Doppler mixing with any explanatory
power.

The offhand way it was tossed out in that forum, as if
"everybody know that", tells me it may be more than
conjecture. At any rate, it was a thread killing answer and
those ladies and gentlemen of learning don't often let
nonsense go unchallenged.

My belief that it exists for all wave phenomenon comes from
realizing that all the acoustic cases we have looked at have
EM counterparts. This is particularly important because the
primary attempts at proving the old model for it in
loudspeakers requires that the wave be longitudinal and it
is well known that in EM it is transverse.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
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Anonymous
August 30, 2004 8:29:36 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

> I believe it goes beyond acoustics. Doppler mixing occurs with _any_ kind
> of wave propegation where there is frequency dependant coupling between Tx
> and Rx. That, at least, is my conjecture. It is not original. It was
> one of the short answers I got to my questions about this for the acoustic
> wave case in sci.physics.research a few weeks ago. It was an epiphany for
> me because it explains, in principle at least, every aspect of the
> phenomenon that has been noted, including my lesser conjecture that it
> does not occur with anything generating plane waves. When that is finally
> shown then the frequency dependant coupling conjecture is the only
> remaining candidate for Doppler mixing with any explanatory power.
>
> The offhand way it was tossed out in that forum, as if "everybody know
> that", tells me it may be more than conjecture. At any rate, it was a
> thread killing answer and those ladies and gentlemen of learning don't
> often let nonsense go unchallenged.
>
> My belief that it exists for all wave phenomenon comes from realizing that
> all the acoustic cases we have looked at have EM counterparts. This is
> particularly important because the primary attempts at proving the old
> model for it in loudspeakers requires that the wave be longitudinal and it
> is well known that in EM it is transverse.

Hmmm... I can understand in principle how the piston motion in a
loudspeaker moving in the same direction as a p-wave could potentially[1]
give rise to Doppler phase shift (or frequency modulation in the case of
multiple frequencies).

I am having a lot more difficulty envisioning the same mechanism for, say, a
radio transmitter. I'm not sure what "velocity" we're talking about in the
case of EM radiation. Of course, it would take a lot more of whatever that
velocity is, to get a measurable red shift/blue shift when 'c' is the speed
of light.

[1] I'm still not completely convinced that conservation of energy and other
physical properties of sound don't cancel out the proposed Doppler effect in
an acoustic radiator such as a loudspeaker. I really don't have a vested
interest either way. I'm just curious, and I want to get at the truth of the
matter. Loudspeaker designs aren't going to change any, regardless of the
results. We already know how to reduce IM and THD by using horns and big
woofers to reduce the cone velocity and excursion. The same treatment would
work for Doppler.
Anonymous
August 30, 2004 8:29:37 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Karl Uppiano wrote:


> Hmmm... I can understand in principle how the piston motion in a
> loudspeaker moving in the same direction as a p-wave could potentially[1]
> give rise to Doppler phase shift (or frequency modulation in the case of
> multiple frequencies).

I agree that on first blush it sure looks that way. On
deeper reflection you realize that the position that the
piston is in at any instant is exactly the right one to be
imparting its instantaneous velocity to the wave. It just
can't be otherwise because their relationship is fixed by
first order calculus. It is _in_ the wave. It is part of
it at its interface to it. To then count velocity a second
time in trying to calculate a dynamic doppler shift will
lead to all kinds of problems and difficulty with general
proofs because it's wrong to do that. If you see that the
piston's position and velocity are always appropriate to the
wave it is generating and in which it is embedded then you
see that consideration of further effects due to its
velocity are redundant. The flaw with every attempt at a
proof that I've seen, including the most recent, is that
double counting which in the general case ends up being way
more than double.

If you try to find a theoretical solution this way that
applies to any arbitrary signal rather than some particular
one, the redundant acounting leads logically to recursive
definitions in the formulae and an infinite regress without
termination or convergence. This is just what I would
expect from such a conceptual error. Each time you put the
velocity into the equation, you have to put it in again
within the function defining it to acount for its "Doppler"
effects. Interminably. This is a mathematical hint that
you are doing something fundamentally wrong.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
August 30, 2004 8:29:38 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Bob Cain wrote:


> If you try to find a theoretical solution this way that
> applies to any arbitrary signal rather than some particular
> one, the redundant acounting leads logically to recursive
> definitions in the formulae and an infinite regress without
> termination or convergence.

Depending on the how you formulate it (among equivalent
options) you can end up with the time variable being defined
recursively with respect to itself. Wierd, that.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
August 30, 2004 12:15:06 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

>
> I am having a lot more difficulty envisioning the same mechanism for, say, a
> radio transmitter. I'm not sure what "velocity" we're talking about in the
> case of EM radiation. Of course, it would take a lot more of whatever that
> velocity is, to get a measurable red shift/blue shift when 'c' is the speed
> of light.
>
>

Doppler does of course occur for radio and light waves as well.

The velocity is the relative velocity between the Rx and Tx and does
not involve the medium of propogation.

Mark
Anonymous
August 31, 2004 8:31:53 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

"Mark" <makolber@yahoo.com> wrote in message
news:3367f36e.0408300715.2f164851@posting.google.com...
>>
>> I am having a lot more difficulty envisioning the same mechanism for,
>> say, a
>> radio transmitter. I'm not sure what "velocity" we're talking about in
>> the
>> case of EM radiation. Of course, it would take a lot more of whatever
>> that
>> velocity is, to get a measurable red shift/blue shift when 'c' is the
>> speed
>> of light.
>>
>>
>
> Doppler does of course occur for radio and light waves as well.
>
> The velocity is the relative velocity between the Rx and Tx and does
> not involve the medium of propogation.

What I thought was being discussed was some sort of "mechanism" by which an
EM radiator would "self-Doppler" by the same mechanism that is being
proposed for loudspeakers. My comment was, I can see where they're getting
the inspiration for Doppler in loudspeakers (even if I'm still not convinced
it's intrinsic to their fundamental operation, all things considered), but I
don't see a similar mechanism for EM radiation. That's all.

I completely understand how red shift and blue shift come about in the
standard Doppler equations.
Anonymous
August 31, 2004 8:31:54 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Karl Uppiano wrote:


> I completely understand how red shift and blue shift come about in the
> standard Doppler equations.

It's my conjecture that the cause of Doppler mixing is
frequency dependant coupling between Tx and Rx and that
should apply to any wave mechanical system.

The usual red and blue shift are the consequence of there
being no DC coupling between Tx and Rx in EM theory.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
August 31, 2004 10:31:19 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

....
> >>
> >> I am having a lot more difficulty envisioning the same mechanism for,
> >> say, a
> >> radio transmitter. I'm not sure what "velocity" we're talking about in
> >> the
> >> case of EM radiation. Of course, it would take a lot more of whatever
> >> that
> >> velocity is, to get a measurable red shift/blue shift when 'c' is the
> >> speed
> >> of light.
> >>
> >>
> >
> > Doppler does of course occur for radio and light waves as well.
> >
> > The velocity is the relative velocity between the Rx and Tx and does
> > not involve the medium of propogation.
>
> What I thought was being discussed was some sort of "mechanism" by which an
> EM radiator would "self-Doppler" by the same mechanism that is being
> proposed for loudspeakers. My comment was, I can see where they're getting
> the inspiration for Doppler in loudspeakers (even if I'm still not convinced
> it's intrinsic to their fundamental operation, all things considered), but I
> don't see a similar mechanism for EM radiation. That's all.
>
> I completely understand how red shift and blue shift come about in the
> standard Doppler equations.

OK, Well the fundamental difference is that a radio Tx antenna does
not have to move to create a wave. A speaker cone on the other hand
is moving to create a sound wave. Relative motion between the Rx and
Tx creates Doppler.

There is no relative motion for an RF radiator. There is relative
motion (in general) for a sound radiator. Bob has come up with some
very specific cases where there can be no relative motion between
acoustical Rx and Tx so those are exception cases.

Mark
August 31, 2004 3:36:28 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro (More info?)

"Mark" <makolber@yahoo.com> wrote in message
news:3367f36e.0408310531.27618723@posting.google.com...
> OK, Well the fundamental difference is that a radio Tx antenna does
> not have to move to create a wave. A speaker cone on the other hand
> is moving to create a sound wave. Relative motion between the Rx and
> Tx creates Doppler.

Not exactly true, at the very least, the EMF on the antenna will cause it to
vibrate in the earth's magnetic field, and while this has no connection to
it's radiation, Tx is still moving relative to Rx, and while this motion is
extremely small, considering the relative wavelengths and propagation
speeds, an exact analysis may find that it is similar to the speaker's cone
motion when reproducing music.

> There is no relative motion for an RF radiator. There is relative
> motion (in general) for a sound radiator. Bob has come up with some
> very specific cases where there can be no relative motion between
> acoustical Rx and Tx so those are exception cases.
>
It still has not been established beyond a doubt that there is relative
motion concerning Tx and Rx with speaker audio reproduction. There remains
an element doubt that the surface of the cone is really the literal sound
source. The center of motion of the cone may actually be the literal sound
source, and this point doesn't move relative to the listener under normal
circumstances. Thus, it might even be postulated that the Tx/Rx relative
position with respect to a speaker reproducing music might be more stable
that that of an antenna radiating RF in the earth's magnetic field.
I'm not presenting this as an actuality, I'm adding yet another real
possibility that shows how much we are assuming and how little of what we
assuming on a basic level is really firmly grounded in fact. The speaker
Doppler distortion debate has popped up here and there over the last forty
years are so, with various "proofs" that actually proved very little either
way, and I suspect that we may be carrying the debate into new territory
this time. It would behoove us to go all the way back and start from the
very beginning in examining what we all "know" about the phenomonen. The pay
off is that if we really are into new territory, we can all take pride in
our parts in the breaking of new ground. Even if it turns out that the old
school view is correct, we can still be proud in finally proving it once and
for all. It's going to take time, but I look at as a win/win situation, no
matter which side we started out on. :-)
Anonymous
August 31, 2004 9:56:26 PM

Archived from groups: rec.audio.pro,rec.audio.tech,rec.radio.amateur.antenna (More info?)

In article <qN1Zc.47773$%n4.33843@bignews6.bellsouth.net>,
noham@nospam.com says...
>
> "Mark" <makolber@yahoo.com> wrote in message
> news:3367f36e.0408310531.27618723@posting.google.com...
> > OK, Well the fundamental difference is that a radio Tx antenna does
> > not have to move to create a wave. A speaker cone on the other hand
> > is moving to create a sound wave. Relative motion between the Rx and
> > Tx creates Doppler.
>
> Not exactly true, at the very least, the EMF on the antenna will cause it to
> vibrate in the earth's magnetic field, and while this has no connection to
> it's radiation, Tx is still moving relative to Rx, and while this motion is
> extremely small, considering the relative wavelengths and propagation
> speeds, an exact analysis may find that it is similar to the speaker's cone
> motion when reproducing music.
>
> > There is no relative motion for an RF radiator. There is relative
> > motion (in general) for a sound radiator. Bob has come up with some
> > very specific cases where there can be no relative motion between
> > acoustical Rx and Tx so those are exception cases.
> >
> It still has not been established beyond a doubt that there is relative
> motion concerning Tx and Rx with speaker audio reproduction. There remains
> an element doubt that the surface of the cone is really the literal sound
> source. The center of motion of the cone may actually be the literal sound
> source, and this point doesn't move relative to the listener under normal
> circumstances. Thus, it might even be postulated that the Tx/Rx relative
> position with respect to a speaker reproducing music might be more stable
> that that of an antenna radiating RF in the earth's magnetic field.
> I'm not presenting this as an actuality, I'm adding yet another real
> possibility that shows how much we are assuming and how little of what we
> assuming on a basic level is really firmly grounded in fact. The speaker
> Doppler distortion debate has popped up here and there over the last forty
> years are so, with various "proofs" that actually proved very little either
> way, and I suspect that we may be carrying the debate into new territory
> this time. It would behoove us to go all the way back and start from the
> very beginning in examining what we all "know" about the phenomonen. The pay
> off is that if we really are into new territory, we can all take pride in
> our parts in the breaking of new ground. Even if it turns out that the old
> school view is correct, we can still be proud in finally proving it once and
> for all. It's going to take time, but I look at as a win/win situation, no
> matter which side we started out on. :-)
>
>
>
Why not invite some of the rec.radio.amateur.antenna experts to comment?
Anonymous
August 31, 2004 9:56:27 PM

Archived from groups: rec.audio.pro,rec.audio.tech,rec.radio.amateur.antenna (More info?)

Good grief!
"I Care" <icare@whocares.com> wrote in message
news:MPG.1b9e5b906e879d009896ba@netnews.comcast.net...
> In article <qN1Zc.47773$%n4.33843@bignews6.bellsouth.net>,
> noham@nospam.com says...
> >
> > "Mark" <makolber@yahoo.com> wrote in message
> > news:3367f36e.0408310531.27618723@posting.google.com...
> > > OK, Well the fundamental difference is that a radio Tx antenna does
> > > not have to move to create a wave. A speaker cone on the other hand
> > > is moving to create a sound wave. Relative motion between the Rx and
> > > Tx creates Doppler.
> >
> > Not exactly true, at the very least, the EMF on the antenna will cause
it to
> > vibrate in the earth's magnetic field, and while this has no connection
to
> > it's radiation, Tx is still moving relative to Rx, and while this motion
is
> > extremely small, considering the relative wavelengths and propagation
> > speeds, an exact analysis may find that it is similar to the speaker's
cone
> > motion when reproducing music.
> >
> > > There is no relative motion for an RF radiator. There is relative
> > > motion (in general) for a sound radiator. Bob has come up with some
> > > very specific cases where there can be no relative motion between
> > > acoustical Rx and Tx so those are exception cases.
> > >
> > It still has not been established beyond a doubt that there is
relative
> > motion concerning Tx and Rx with speaker audio reproduction. There
remains
> > an element doubt that the surface of the cone is really the literal
sound
> > source. The center of motion of the cone may actually be the literal
sound
> > source, and this point doesn't move relative to the listener under
normal
> > circumstances. Thus, it might even be postulated that the Tx/Rx relative
> > position with respect to a speaker reproducing music might be more
stable
> > that that of an antenna radiating RF in the earth's magnetic field.
> > I'm not presenting this as an actuality, I'm adding yet another real
> > possibility that shows how much we are assuming and how little of what
we
> > assuming on a basic level is really firmly grounded in fact. The speaker
> > Doppler distortion debate has popped up here and there over the last
forty
> > years are so, with various "proofs" that actually proved very little
either
> > way, and I suspect that we may be carrying the debate into new territory
> > this time. It would behoove us to go all the way back and start from the
> > very beginning in examining what we all "know" about the phenomonen. The
pay
> > off is that if we really are into new territory, we can all take pride
in
> > our parts in the breaking of new ground. Even if it turns out that the
old
> > school view is correct, we can still be proud in finally proving it once
and
> > for all. It's going to take time, but I look at as a win/win situation,
no
> > matter which side we started out on. :-)
> >
> >
> >
> Why not invite some of the rec.radio.amateur.antenna experts to comment?
August 31, 2004 11:25:26 PM

Archived from groups: rec.audio.pro,rec.audio.tech,rec.radio.amateur.antenna (More info?)

> > > OK, Well the fundamental difference is that a radio Tx antenna does
> > > not have to move to create a wave. A speaker cone on the other hand
> > > is moving to create a sound wave. Relative motion between the Rx and
> > > Tx creates Doppler.
> >
> > Not exactly true, at the very least, the EMF on the antenna will cause it to
> > vibrate in the earth's magnetic field, and while this has no connection to
> > it's radiation, Tx is still moving relative to Rx, and while this motion is
> > extremely small, considering the relative wavelengths and propagation
> > speeds, an exact analysis may find that it is similar to the speaker's cone
> > motion when reproducing music.


Very very very small especially when the Doppler effect is relative to
the speed of light and not sound. Also it would have to vibrate at RF
frequencies.


> >
> > > There is no relative motion for an RF radiator. There is relative
> > > motion (in general) for a sound radiator. Bob has come up with some
> > > very specific cases where there can be no relative motion between
> > > acoustical Rx and Tx so those are exception cases.
> > >
> > It still has not been established beyond a doubt that there is relative
> > motion concerning Tx and Rx with speaker audio reproduction. There remains
> > an element doubt that the surface of the cone is really the literal sound
> > source. The center of motion of the cone may actually be the literal sound
> > source, and this point doesn't move relative to the listener under normal
> > circumstances.

But if you consider both the 50 Hz and 4 kHz vibrations cone, the
sound source at 4 kHz (wherever you consider it be) is certainly
moving at 50 Hz. Even if you consider the center of motion at 4 kHz
to be the sound source, that center is moving at 50 Hz. That is the
entire point!

Mark
Anonymous
September 1, 2004 1:43:17 AM

Archived from groups: rec.audio.pro (More info?)

"Bob Cain" <arcane@arcanemethods.com> wrote in message
news:cgu73d0gin@enews1.newsguy.com...
>
>
> Karl Uppiano wrote:
>
> > From the looks of it, Doppler
> > Distortion might be intrinsic to fundamental loudspeaker operation, but
it
> > hasn't reached the status of a physical law just yet.
>
> I believe it goes beyond acoustics. Doppler mixing occurs
> with _any_ kind of wave propegation where there is frequency
> dependant coupling between Tx and Rx. That, at least, is my
> conjecture. It is not original. It was one of the short
> answers I got to my questions about this for the acoustic
> wave case in sci.physics.research a few weeks ago. It was
> an epiphany for me because it explains, in principle at
> least, every aspect of the phenomenon that has been noted,
> including my lesser conjecture that it does not occur with
> anything generating plane waves. When that is finally shown
> then the frequency dependant coupling conjecture is the only
> remaining candidate for Doppler mixing with any explanatory
> power.

Going back to the audio realm, have you considered other sound sources?
Think of the motion of a piano string and all of the sub-sections vibrating,
what that does to higher frequency pitches that are generated from the same
string. The sound coming from different sections would have different
modulations (opposite modulations I guess).

Going back to loudspeakers, what about the difference in pressure as the
speaker changes direction? Doesn't sound travel slower as the air pressure
drops? This should add to the doppler effect since the speaker moving into
the cabinet will create negative pressure to the room, lowering the
transmission speed at the same time the speaker is moving away from the
listener.

Personally I don't think any of these effects actually produce anything
audible, or maybe even measurable, though I have nothing but intuition to
base my opinion on.

Sean
Anonymous
September 1, 2004 1:48:51 AM

Archived from groups: rec.audio.pro (More info?)

Sean Conolly wrote:


> Going back to the audio realm, have you considered other sound sources?
> Think of the motion of a piano string and all of the sub-sections vibrating,
> what that does to higher frequency pitches that are generated from the same
> string. The sound coming from different sections would have different
> modulations (opposite modulations I guess).

The thing is that at this point we have no idea whatsoever
what the magnitude of the real effect might be. It might be
a signifigant thing or of no consequence at all. There is
as yet no mixing theory to guide the way.

>
> Going back to loudspeakers, what about the difference in pressure as the
> speaker changes direction? Doesn't sound travel slower as the air pressure
> drops? This should add to the doppler effect since the speaker moving into
> the cabinet will create negative pressure to the room, lowering the
> transmission speed at the same time the speaker is moving away from the
> listener.

Yeah, the speed of sound depends on density, but to try and
add that in again so as to account for it as separate effect
is to redundantly account for the effect of pressure. Same
error as considering the piston to be generating the
velocity wave and distorting it at the same time due to
Doppler effects.

>
> Personally I don't think any of these effects actually produce anything
> audible, or maybe even measurable, though I have nothing but intuition to
> base my opinion on.

Nor I, but a theory that can predict it is being worked on.
I've solicited the help of the theoretical physicist who
concured with me that Doppler mixing had nothing to do with
what happens at the piston/air interface and first stated
that it was a function of frequency dependant impedences and
the couplings between Tx and Rx which they affect. No
response as of yet to my request.

My first reading of what he said made me think that it was
just based on the net frequency dependant transfer function
between Tx and Rx but reading it again, I think it might be
more complicated than that and be an integral of the
impedence along the line connecting them or some other
function defined in terms of all its values along the line.
That could be a nasty calculation indeed.

In any event, any calculation will have to assume some
working geometry of speaker and cabinet or baffle with
enough symmetry to yield a tractable model for which to
solve the acoustic wave equation at least along the line
joining Tx and Rx. This is not an easy problem at all.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
September 4, 2004 9:04:03 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

In
alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics,
"Karl Uppiano" <karl.uppiano@verizon.net> wrote:

>Hmmm... I can understand in principle how the piston motion in a
>loudspeaker moving in the same direction as a p-wave could potentially[1]
>give rise to Doppler phase shift (or frequency modulation in the case of
>multiple frequencies).
>
>I am having a lot more difficulty envisioning the same mechanism for, say, a
>radio transmitter. I'm not sure what "velocity" we're talking about in the
>case of EM radiation. Of course, it would take a lot more of whatever that
>velocity is, to get a measurable red shift/blue shift when 'c' is the speed
>of light.

One type of radio direction finder works through doppler effects.
You may notice on a police car (among other antennas) four antennas on
the roof, each at the corner of a square. The RF front end switches
between these at an audio frequency. Since an antenna closer to the
source will receive the signal with an earlier phase than one further
from the source, the phase jumps when switching. Switching between
four antennas is close enough to an antenna that is rotating at the
switching cycle speed. This adds a small FM signal to the carrier,
which is amplified through the receiver as usual, and then goes to an
FM demodulator. The phase of this signal in relation to the phase of
the clock driving the antenna switching indicates the direction of the
signal being received. Thus police can locate a Lojak signal from a
stolen car.

>[1] I'm still not completely convinced that conservation of energy and other
>physical properties of sound don't cancel out the proposed Doppler effect in
>an acoustic radiator such as a loudspeaker. I really don't have a vested
>interest either way. I'm just curious, and I want to get at the truth of the
>matter. Loudspeaker designs aren't going to change any, regardless of the
>results. We already know how to reduce IM and THD by using horns and big
>woofers to reduce the cone velocity and excursion. The same treatment would
>work for Doppler.
>

-----
http://mindspring.com/~benbradley
Anonymous
September 4, 2004 9:09:07 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

On Mon, 30 Aug 2004 22:42:26 -0700, Bob Cain
<arcane@arcanemethods.com> wrote:

>
>
>Karl Uppiano wrote:
>
>
>> I completely understand how red shift and blue shift come about in the
>> standard Doppler equations.
>
>It's my conjecture that the cause of Doppler mixing is
>frequency dependant coupling between Tx and Rx and that

Just what is frequency dependent coupling, and how does it cause
(or how is it related to) the Doppler effect? I've read what you've
written before, but I haven't followed it.

>should apply to any wave mechanical system.
>
>The usual red and blue shift are the consequence of there
>being no DC coupling between Tx and Rx in EM theory.

Hmm. If you charge the TX positive and charge the RX negative, is
that not DC coupling? And I don't see the significance or relevance of
DC coupling.
My understanging has always been that red shift and blue shift are
always the result of relative mtion between the TX and RX, and nothing
else. I don't see how anything else COULD have anything to do with it.

>Bob

-----
http://mindspring.com/~benbradley
Anonymous
September 4, 2004 9:09:08 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Ben Bradley wrote:


> Just what is frequency dependent coupling, and how does it cause
> (or how is it related to) the Doppler effect? I've read what you've
> written before, but I haven't followed it.

It says in its simplest form that the mixing of two
frequencies between Tx and Rx that produces harmonics is a
function of the comparative magnitude of the transfer
function between Tx and Rx for those two frequencies. If
they couple with the same magnitude they don't mix. If
different, they do. I say magnitude because I don't yet
understand the mathematical details of this to know what
will happen if the magnitudes are the same and the group
delay is different

This also means that one will hear different Doppler mixing
at different positions in space relative to an emitter if
the frequency dependant directional patterns to the two
points are different. It will also change as you get closer
or further away. In the limit of being up very tight and up
close to the piston, it will barely exist at all.

The conjecture follows from the finding that when coupling
is frequency independant, such as with a plane wave or a
piston in a tube, mixing does not occur and transmission is
completely linear with the tube acting simply as a real
impedance transmission line with delay. (I recognize that
is still considered equivocal and I have a new approach to
explaining why it is true that is written up and being
sanity checked. In fact, I'd appreciate a few more sanity
checkers before I post a link if anyone is interested in
taking shots at it.)

It does occur in situations where there is obvious frequency
dependant coupling such as a sound source moving with
constant velocity in the free field where no DC coupling can
occur and with the example of a speaker emitting a tone
while swinging on a long enough pendulum to give it a decent
velocity at bottom dead center. In the latter case you
would definitely hear a sinusoidally varying pitch from the
speaker and it is my conjecture that the mixing that is
heard is due to the very low coupling between Tx and Rx at
the frequency of the pendulum. If the resonant frequency of
that pendulum was somehow high enough so that its action was
coupled about as well as the tone from the speaker then you
wouldn't hear mixing.

> Hmm. If you charge the TX positive and charge the RX negative, is
> that not DC coupling? And I don't see the significance or relevance of
> DC coupling.

I don't think electrostatics are included in Maxwell's
equations. I believe a time rate of change is required in
them but if there is and the conditions are such that the
coupling of that change is less than the coupling at higher
frequencies, then yes there will be the kind of Doppler
mixing I've been talking about. It will also occur if the
distance between Tx and Rx is changing in a non-constant way
and the frequency of that change is out of the flat passband
of the Tx/Rx.

> My understanging has always been that red shift and blue shift are
> always the result of relative mtion between the TX and RX, and nothing
> else. I don't see how anything else COULD have anything to do with it.

It is also a matter of how that relative motion is coupled
between the Tx and Rx through the EM field. Constant motion
is not coupled at all and the result is the standard Doppler
equation.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
September 4, 2004 10:59:57 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

"Ben Bradley" <ben_nospam_bradley@mindspring.com> wrote in message
news:7oiij0hi3hjdu4lqjbv1pp8gh3ass4j5rr@4ax.com...
> In
> alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics,
> "Karl Uppiano" <karl.uppiano@verizon.net> wrote:
>
>>Hmmm... I can understand in principle how the piston motion in a
>>loudspeaker moving in the same direction as a p-wave could potentially[1]
>>give rise to Doppler phase shift (or frequency modulation in the case of
>>multiple frequencies).
>>
>>I am having a lot more difficulty envisioning the same mechanism for, say,
>>a
>>radio transmitter. I'm not sure what "velocity" we're talking about in the
>>case of EM radiation. Of course, it would take a lot more of whatever that
>>velocity is, to get a measurable red shift/blue shift when 'c' is the
>>speed
>>of light.
>
> One type of radio direction finder works through doppler effects.
> You may notice on a police car (among other antennas) four antennas on
> the roof, each at the corner of a square. The RF front end switches
> between these at an audio frequency. Since an antenna closer to the
> source will receive the signal with an earlier phase than one further
> from the source, the phase jumps when switching. Switching between
> four antennas is close enough to an antenna that is rotating at the
> switching cycle speed. This adds a small FM signal to the carrier,
> which is amplified through the receiver as usual, and then goes to an
> FM demodulator. The phase of this signal in relation to the phase of
> the clock driving the antenna switching indicates the direction of the
> signal being received. Thus police can locate a Lojak signal from a
> stolen car.

I understand completely how the traditional Doppler effect applies to all
radiating signals, sound and electromagnetic, from DC to X-rays. But the
type of Doppler shift that is being hypothesized in this newsgroup for a
single stationary loudspeaker is *self-induced* due to the motion of the
speaker cone in the same direction as the p-wave propagation (but see my
footnote [1] below).

I can't envision any similar mechanism for *self-induced* Doppler shift in
radio signals from a single stationary antenna. To begin with, there are no
moving parts. If you count the peak electron velocity, it's at right angles
to the direction of the t-wave propagation.

>>[1] I'm still not completely convinced that conservation of energy and
>>other
>>physical properties of sound don't cancel out the proposed Doppler effect
>>in
>>an acoustic radiator such as a loudspeaker. I really don't have a vested
>>interest either way. I'm just curious, and I want to get at the truth of
>>the
>>matter. Loudspeaker designs aren't going to change any, regardless of the
>>results. We already know how to reduce IM and THD by using horns and big
>>woofers to reduce the cone velocity and excursion. The same treatment
>>would
>>work for Doppler.
>>
>
> -----
> http://mindspring.com/~benbradley
Anonymous
September 4, 2004 8:18:20 PM

Archived from groups: alt.music.home-studio,rec.audio.tech (More info?)

Ben Bradley wrote:

> On Mon, 30 Aug 2004 22:42:26 -0700, Bob Cain
> Just what is frequency dependent coupling, and how does it cause
> (or how is it related to) the Doppler effect? I've read what you've
> written before, but I haven't followed it.

Please do not post these anti-cain messages on the alt...acoustics news
group as they do not relate to acoustics.

Angelo Campanella
Anonymous
September 4, 2004 8:23:11 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro (More info?)

Karl Uppiano wrote:
> type of Doppler shift that is being hypothesized in this newsgroup for a
> single stationary loudspeaker is *self-induced* due to the motion of the
> speaker cone in the same direction as the p-wave propagation

Please do not cross-post these loudspeaker articles in the
alt...acoustics news group because they confusing without providing any
significant progress. Confine them to audio groups.

Angelo Campanella
Anonymous
September 4, 2004 8:23:12 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Angelo Campanella wrote:

> Karl Uppiano wrote:
>
>> type of Doppler shift that is being hypothesized in this newsgroup for
>> a single stationary loudspeaker is *self-induced* due to the motion of
>> the speaker cone in the same direction as the p-wave propagation
>
>
> Please do not cross-post these loudspeaker articles in the
> alt...acoustics news group because they confusing without providing any
> significant progress. Confine them to audio groups.

Please bugger off, Angelo. If Doppler mixing isn't a
legitimate topic of discussion in an acoustics group then
nothing is. If the group wishes only to discuss applied
acoustics then the name is wrong and it certainly shouldn't
contain "physics".

As to progress, I'll be the judge of that and as to what
usenet communities might contribute to the topic, I'll be
the judge of that as well.

If this topic is of no interest to you and noise from the
"peanut gallery" offends you then the "k" key from your
reader will very likely record that fact in an affective way.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
September 4, 2004 11:33:07 PM

Archived from groups: alt.music.home-studio,rec.audio.tech (More info?)

Angelo Campanella <a.campanella@att.net> writes:

> Ben Bradley wrote:
>
>> On Mon, 30 Aug 2004 22:42:26 -0700, Bob Cain
>> Just what is frequency dependent coupling, and how does it cause
>> (or how is it related to) the Doppler effect? I've read what you've
>> written before, but I haven't followed it.
>
> Please do not post these anti-cain messages on the alt...acoustics
> news group as they do not relate to acoustics.
>
> Angelo Campanella

Hey Angelo,

Go fart on a match. People who have this 'netpolice' tendency
really beg for abuse.
--
% Randy Yates % "Rollin' and riding and slippin' and
%% Fuquay-Varina, NC % sliding, it's magic."
%%% 919-577-9882 %
%%%% <yates@ieee.org> % 'Living' Thing', *A New World Record*, ELO
http://home.earthlink.net/~yatescr
Anonymous
September 4, 2004 11:33:08 PM

Archived from groups: alt.music.home-studio,rec.audio.tech (More info?)

Randy Yates wrote:

> Go fart on a match. People who have this 'netpolice' tendency
> really beg for abuse.

Wish I'd had the balls to say that.

Hey, Randy, if you haven't, please check the mailbox for
your posted address. I sent you something last night that
I'd appreciate an opinion on.


Thanks,

Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
September 4, 2004 11:41:20 PM

Archived from groups: alt.music.home-studio,rec.audio.tech (More info?)

"Randy Yates" <yates@ieee.org> wrote in message
news:3c1xyglq.fsf@ieee.org...
> Angelo Campanella <a.campanella@att.net> writes:
>
>> Ben Bradley wrote:
>>
>>> On Mon, 30 Aug 2004 22:42:26 -0700, Bob Cain
>>> Just what is frequency dependent coupling, and how does it cause
>>> (or how is it related to) the Doppler effect? I've read what you've
>>> written before, but I haven't followed it.
>>
>> Please do not post these anti-cain messages on the alt...acoustics
>> news group as they do not relate to acoustics.
>>
>> Angelo Campanella
>
> Hey Angelo,
>
> Go fart on a match. People who have this 'netpolice' tendency
> really beg for abuse.

Is there a moderated version of this NG? Maybe that would put a filter on
some of the off-topic stuff.
Anonymous
September 5, 2004 3:03:33 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

On Sat, 04 Sep 2004 16:14:28 -0700, Bob Cain
<arcane@arcanemethods.com> wrote:

>Please bugger off, Angelo. If Doppler mixing isn't a
[snip]

My, my, my. Getting a little testy?

The title of this thread should give a clue as to who should really
consider buggering off.

>As to progress, I'll be the judge of that and as to what
>usenet communities might contribute to the topic, I'll be
>the judge of that as well.

Judge, jury and executioner?

>If this topic is of no interest to you and noise from the
>"peanut gallery" offends you then the "k" key from your
>reader will very likely record that fact in an affective way.

Angelo should probably get his kill file rolling, because he's not
enjoying this. Kill files are the only real moderator on usenet these
days.

No kill file for me. I'm enjoying the posts, for reasons I've given
elsewhere in these discussions.

Ken Plotkin
Anonymous
September 5, 2004 4:18:19 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Ken Plotkin <kplotkin@nospam-cox.net> wrote in message news:<h80lj0ttv623s5l1umscrglqmjpruisp04@4ax.com>...
> On Sat, 04 Sep 2004 16:14:28 -0700, Bob Cain
> <arcane@arcanemethods.com> wrote:
>
> >Please bugger off, Angelo. If Doppler mixing isn't a
> [snip]
>
> My, my, my. Getting a little testy?
>
> The title of this thread should give a clue as to who should really
> consider buggering off.
>
> >As to progress, I'll be the judge of that and as to what
> >usenet communities might contribute to the topic, I'll be
> >the judge of that as well.
>
> Judge, jury and executioner?


Not entirely. As has been pointed out previously in these groups, Bob
Cain is little more than a technically-inept, arrogant a--hole who's
integrity, dignity and self-respect lost out long ago to his
overly-inflated ego.
Anonymous
September 5, 2004 4:55:20 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

The Ghost wrote:

> Not entirely. As has been pointed out previously in these groups, Bob
> Cain is little more than a technically-inept, arrogant a--hole who's
> integrity, dignity and self-respect lost out long ago to his
> overly-inflated ego.

Something I've found to be universal and almost always true
is that one must look at what an individual consistently
accuses others of to discover the true nature of that
individual. It is there that he paints his self portrait
and it is that part of himself that he most hates which he
projects onto others in the most hateful, repellent and
offensive ways.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
September 6, 2004 5:12:31 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Bob Cain <arcane@arcanemethods.com> wrote in message news:<chfq9702a12@enews2.newsguy.com>...
> The Ghost wrote:
>
> > Not entirely. As has been pointed out previously in these groups, Bob
> > Cain is little more than a technically-inept, arrogant a--hole who's
> > integrity, dignity and self-respect lost out long ago to his
> > overly-inflated ego.
>
> Something I've found to be universal and almost always true
> is that one must look at what an individual consistently
> accuses others of to discover the true nature of that
> individual. It is there that he paints his self portrait
> and it is that part of himself that he most hates which he
> projects onto others in the most hateful, repellent and
> offensive ways.
> Bob

I think I've heard that rationalization from you before. The problem
with it is that if you apply it to yourself, and to the things that
you have said about me both recently and in the past, the picture of
Bob Cain isn't any different than the one I painted above. This sort
of disfunctional thinking on your part is undoubtedly at the root of
your inability to recognize and acknowledge scientific truth and why
you persist in denying reality and the obvious, and why you find
solace in engaging in the sharing of uneducated opinion that
substitutes in the audio groups for intelligent, rational and reasoned
thought.
Anonymous
September 6, 2004 7:18:33 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro (More info?)

The Ghost wrote:


>>Something I've found to be universal and almost always true
>>is that one must look at what an individual consistently
>>accuses others of to discover the true nature of that
>>individual. It is there that he paints his self portrait
>>and it is that part of himself that he most hates which he
>>projects onto others in the most hateful, repellent and
>>offensive ways.
>>Bob
>
>
> I think I've heard that rationalization from you before. The problem
> with it is that if you apply it to yourself, and to the things that
> you have said about me both recently and in the past,

I said "consistently". If you do a little research you'll
find that I've reserved such treatment almost entirely for
you and in reponse to years of being stalked by you, and
most recently to your recent context free clipping of my
responses to you to forward to someone I was having a
productive conversation with. Your poisoning of that
situation was successful. Congratulations. That is
something I will _not_ forget. I suppose by now there are a
rather large number of people you pray you will never find
yourself in the same room with.

Did you also succeed in getting Cliff Kaminsky fired over a
personal issue after you called the VP and president of the
company he worked for? It was my refusal to assist you in
_any_ of that insanity which initiated your stalking of me 3
years ago. I still have a record of that interchange,
should you wish to debate the issue (up to where I got the
assistance of my ISP to filter your drool from my mailbox.)

If you will research your own posting history, you'll find
that you are an absolutely equal opportunity boor. You
apply the ugliness that best descibes you indiscriminately
and consistently to a remarkable number of people. Why did
Gary Sokolich disappear from the net for quite some period
of time and reemerge as frothing at the mouth as ever under
the pseudonym "The Ghost?"

To anyone who should care, not sure why they would want to,
what I've said here is easily verifiable. It would be
appreciated by a lot of people if you would just slither
back under your rock.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
September 7, 2004 11:47:08 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

"The Ghost" <the_ghostbuster@netzero.com> wrote in message
news:b5fb78ba.0409061212.93f1b4f@posting.google.com...
> Bob Cain <arcane@arcanemethods.com> wrote in message
news:<chfq9702a12@enews2.newsguy.com>...
> > The Ghost wrote:
> >
> > > Not entirely. As has been pointed out previously in these groups, Bob
> > > Cain is little more than a technically-inept, arrogant a--hole who's
> > > integrity, dignity and self-respect lost out long ago to his
> > > overly-inflated ego.
> >
> > Something I've found to be universal and almost always true
> > is that one must look at what an individual consistently
> > accuses others of to discover the true nature of that
> > individual. It is there that he paints his self portrait
> > and it is that part of himself that he most hates which he
> > projects onto others in the most hateful, repellent and
> > offensive ways.
> > Bob
>
> I think I've heard that rationalization from you before. The problem
> with it is that if you apply it to yourself, and to the things that
> you have said about me both recently and in the past, the picture of
> Bob Cain isn't any different than the one I painted above. This sort
> of disfunctional thinking on your part is undoubtedly at the root of
> your inability to recognize and acknowledge scientific truth and why
> you persist in denying reality and the obvious, and why you find
> solace in engaging in the sharing of uneducated opinion that
> substitutes in the audio groups for intelligent, rational and reasoned
> thought.

I've tended to take Bob's side in this simply because I've seen little
but insults and bile in your posts, why won't you take up my invitation to
post scientific evidence of your side in this? Your one attempt was
obvioulsy of the two motive source, train/whistle variety and as such has
absolutely nothing to do with the single complex motive source driven model
presented by a speaker producing a complex musical wave. Your example simply
doesn't apply unless someone is moving the whole speaker back and forth. If
you want folks to believe that you know what you're talking about, then post
some applicable evidence!
Anonymous
September 7, 2004 2:23:58 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

On Tue, 7 Sep 2004 07:47:08 -0500, "Porky" <noham@nospam.com> wrote:


> I've tended to take Bob's side in this simply because I've seen little
>but insults and bile in your posts, why won't you take up my invitation to
>post scientific evidence of your side in this?

He ran an actual experiment, collected data and reported the results.

>Your one attempt was
>obvioulsy of the two motive source, train/whistle variety and as such has
>absolutely nothing to do with the single complex motive source driven model
>presented by a speaker producing a complex musical wave.
[snip]

Like the linear analysis of a piston driving a simple tube with no
losses is more realistic?

Gary's experiment seemed very good to me. He got to the core of the
phenomenon, avoiding issues of the mechanical behavior of a speaker
cone.

If his replies seem sharp, it's because he's run out of patience.

Ken Plotkin
Anonymous
September 7, 2004 3:37:19 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

"Porky" <noham@nospam.com> wrote in message news:<j4i%c.25066$Np2.3232@bignews4.bellsouth.net>...
>
> I've tended to take Bob's side in this simply because I've seen little
> but insults and bile in your posts, why won't you take up my invitation to
> post scientific evidence of your side in this? Your one attempt was
> obvioulsy of the two motive source, train/whistle variety and as such has
> absolutely nothing to do with the single complex motive source driven model
> presented by a speaker producing a complex musical wave. Your example simply
> doesn't apply unless someone is moving the whole speaker back and forth. If
> you want folks to believe that you know what you're talking about, then post
> some applicable evidence!

I don't care whether you and the rest of the "folks" in the audio
groups believe. Furthermore, your inability to understand exactly
what it was that I did and to recognize its validity, is your problem,
not mine.
Anonymous
September 8, 2004 9:23:42 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

On 7 Sep 2004 11:37:19 -0700, the_ghostbuster@netzero.com (The Ghost)
wrote:

>"Porky" <noham@nospam.com> wrote in message news:<j4i%c.25066$Np2.3232@bignews4.bellsouth.net>...
>>
>> I've tended to take Bob's side in this simply because I've seen little
>> but insults and bile in your posts, why won't you take up my invitation to
>> post scientific evidence of your side in this? Your one attempt was
>> obvioulsy of the two motive source, train/whistle variety and as such has
>> absolutely nothing to do with the single complex motive source driven model
>> presented by a speaker producing a complex musical wave. Your example simply
>> doesn't apply unless someone is moving the whole speaker back and forth. If
>> you want folks to believe that you know what you're talking about, then post
>> some applicable evidence!
>
>I don't care whether you and the rest of the "folks" in the audio
>groups believe. Furthermore, your inability to understand exactly
>what it was that I did and to recognize its validity, is your problem,
>not mine.

In other words, you have nothing to offer, and are merely posturing.
Your previous example does *not* have validity to the situation
pertaining to a speaker cone, as is obvious to anyone with a basic
understanding of the physics involved. It is you who seeems to lack
understanding in this matter.................
--

Stewart Pinkerton | Music is Art - Audio is Engineering
Anonymous
September 8, 2004 9:23:43 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

"Stewart Pinkerton" <patent3@dircon.co.uk> wrote in message
news:il5tj0933ioq0hq94juu92stgkjveikcsi@4ax.com...

> In other words, you have nothing to offer, and are merely posturing.
> Your previous example does *not* have validity to the situation
> pertaining to a speaker cone, as is obvious to anyone with a basic
> understanding of the physics involved. It is you who seeems to lack
> understanding in this matter.................

I'm admittedly out of my depth here, but even I could see the experiment had
no bearing on the question at hand. I will attempt to state it simply *and*
accurately, which is no easy task.

The Doppler effect is not disputed. If the distance between the source and
receiver is changing, an apparent shift in frequency will occur.

Doppler Distortion states that since a speaker cone is moving back and
forth, the distance between the source and receiver is changing, thus the
Doppler effect takes place. In the simple example of a speaker producing a
50Hz signal and a 1000Hz signal, the movement to create the lower frequency
is the cause of the Doppler distortion of the higher frequency.

As the cone moves forward once to create the 50Hz frequency, it will
oscillate 20 times to create the 1000Hz signal. I would assume you'd see the
frequency as rising. I hope I stated that accurately.

Bob is making the argument that it's more complicated than that in part
because speaker cone is making a sound wave for both the lower and higher
frequency. The standard Doppler formula makes no mention of the movement
creating a sound wave or even deals with an oscillating movement. Bob is
looking to prove that physics involved in creating the sound waves alters
the basic premise about Doppler distortion. Am I close enough, Bob?

The experiment by Ghost, aka Gary Sokolich, essentially moved a speaker back
and forth. As expected there would be a Doppler shift. The problem with his
experiment is that the movement of the speaker (as opposed to the speaker
cone) did not create any sound waves. It does not *prove* that speaker cone
movement as described above will create Doppler distortion. It does validate
the Doppler effect, but that's not in contention. He might as well have had
the train with the whistle stay still while the listener bungie-jumped above
it and bounced up and down.

Someone posted a formula for determining what one should expect to find with
Doppler distortion. So, it would seem you could set up an experiment with an
actual speaker producing the above frequencies and check out what
frequencies are seen by the source. The mathematical predictions should
include Doppler distortion and any frequency or amplitude modulations which
may result.

If the modulations do not coincide with Doppler distortion frequencies, then
in theory you should be able to measure the resulting frequencies and state
with relative certainty what frequencies were explained by what. If you see
other frequencies, you had better explain what caused them.

And before you ask, no, it ain't gonna be me! Before all this started I
thought oscilloscope was what they used to film movies, like cinemascope.
Anonymous
September 8, 2004 9:23:44 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Jim Carr wrote:


> Bob is making the argument that it's more complicated than that in part
> because speaker cone is making a sound wave for both the lower and higher
> frequency. The standard Doppler formula makes no mention of the movement
> creating a sound wave or even deals with an oscillating movement. Bob is
> looking to prove that physics involved in creating the sound waves alters
> the basic premise about Doppler distortion. Am I close enough, Bob?

Spot on. And I think I now understand the precise mechanism
of that alteration. It's simple enough that I'm hoping the
light will go on elsewere with just a hint or two. One
needs to look carefully at just what is required for the
validity of f'=f/(1+v/c) and what is violated in the usual
local analysis of Doppler distortion that employs the equation.

>
> The experiment by Ghost, aka Gary Sokolich, essentially moved a speaker back
> and forth. As expected there would be a Doppler shift. The problem with his
> experiment is that the movement of the speaker (as opposed to the speaker
> cone) did not create any sound waves.

Rather that the ones it did make due to that motion were not
nearly as well coupled to the microphone as were the higher
frequency ones. I would expect this difference to produce
Doppler distortion. Where that difference can be
eliminated, piston-in-a-tube specifically, no Doppler
products will be measured.

>
> Someone posted a formula for determining what one should expect to find with
> Doppler distortion. So, it would seem you could set up an experiment with an
> actual speaker producing the above frequencies and check out what
> frequencies are seen by the source. The mathematical predictions should
> include Doppler distortion and any frequency or amplitude modulations which
> may result.

Art's math does indeed predict a particular spectrum under
particular conditions and independant of other conditions.
Any experiment should validate its predictions of
independance as well as its predictions of dependance.

>
> If the modulations do not coincide with Doppler distortion frequencies, then
> in theory you should be able to measure the resulting frequencies and state
> with relative certainty what frequencies were explained by what. If you see
> other frequencies, you had better explain what caused them.

This is getting sticky because it is _really_ hard to
predict what a typical speaker will produce as distortion
components. Well nigh impossible. Piezo's are at least as
bad. OTOH, the distortion products due to the speaker
itself are both minimized and made very predictable and
measurable in the case of a push-pull electrostatic which,
for that reason, is what should be used in the experiment.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
September 8, 2004 2:09:52 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Bob Cain wrote:
> Spot on. And I think I now understand the precise mechanism of that
> alteration. It's simple enough that I'm hoping the light will go on
> elsewere with just a hint or two. One needs to look carefully at just
> what is required for the validity of f'=f/(1+v/c) and what is violated
> in the usual local analysis of Doppler distortion that employs the
> equation.

Bob, you have never responded to my suggestion that doppler shift
occurs whenever there has been a change in distance between transmitter
and receiver and that equations like f'=f/(1+v/c) are not as general
as they should be to really understand the phenomenon.

In other words, isn't it sort of a straw man to even say doppler shift
depends on any particular velocity of a driver? Or maybe to put it
better, defining doppler effects based on frequency is too narrow a
definition. There is a much simpler way to define it. Basically, there
will be a net shift in the total propagation time from transmitter to
receiver if the distance between them changes. Thus, things will be
shifted in time.

If you want to look at it a bit more mathematically, total propagation
time is a function of the speed of propagation through the medium and
of distance. Let's consider two points in time: t0 and t1. At
time t0, the total propagation time from trasmitter to receiver is
p0. At time t1, the total propagation time is p1. If there is a net
change in position between t0 and t1, then t1-t0 != (t1+p1)-(t0+p0),
because p0 != p1. But let's call a0 the time that the signal transmitted
at t0 arrives at the receiver, and likewise for a1 and t1. Obviously,
a0 = t0+p0 and a1 = t1+p1, so this means that t1-t0 != a1-a0 if the
transmitter moves with respect to the receiver.

Note that it doesn't matter how the transmitter moves. As long as it
moves by a given amount during that time interval from t0 to t1, it's
pretty much path independent. (Although, of course that doesn't mean
the instantaneous velocity at t0 and t1 don't matter, but there are
an infinite number of paths that still be taken and still have the
same instantaneous velocities at t0 and t1...)

So, my question is, do you agree with this much? If not, I'm interested
to hear what part you don't agree with. But if so, then doesn't it
imply distortion? If you time shift one part of a signal but not
another part, that's distortion, right?

- Logan
Anonymous
September 8, 2004 3:40:38 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Logan Shaw wrote:

> Bob, you have never responded to my suggestion that doppler shift
> occurs whenever there has been a change in distance between transmitter
> and receiver and that equations like f'=f/(1+v/c) are not as general
> as they should be to really understand the phenomenon.

Sorry I failed to respond. I agree. It's not a change of
distance as much as changes in transit time and distance is
only one of the factors involved in that.

> So, my question is, do you agree with this much? If not, I'm interested
> to hear what part you don't agree with. But if so, then doesn't it
> imply distortion? If you time shift one part of a signal but not
> another part, that's distortion, right?

Not in detail. When looking locally at the effect of a
slowly moving piston on its emission of a higher frequency
tone, we have more dynamics going on than just distance
modulation between piston face and a reciever very close to
it compared to the wavelength of the LF component. The
pressure is changing locally due to the LF action, although
it can be considered constant for any given cycle of the HF
tone, the temperature of the air is changing and the air is
moving with the LF component of the piston motion. This
also means that c itself is changing locally. When all of
this is properly factored in, what comes out the bottom?


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
September 8, 2004 11:39:09 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

"Bob Cain" <arcane@arcanemethods.com> wrote in message
news:chmah30ujn@enews1.newsguy.com...

> This is getting sticky because it is _really_ hard to
> predict what a typical speaker will produce as distortion
> components. Well nigh impossible. Piezo's are at least as
> bad. OTOH, the distortion products due to the speaker
> itself are both minimized and made very predictable and
> measurable in the case of a push-pull electrostatic which,
> for that reason, is what should be used in the experiment.

Interesting. I wonder if using something like 50Hz and 51Hz would be better
to use than say 50Hz and 1000Hz.
September 9, 2004 2:31:29 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

"Jim Carr" <jim@azwebpages.com> wrote in message
news:tkx%c.77944$yh.63674@fed1read05...
> "Stewart Pinkerton" <patent3@dircon.co.uk> wrote in message
> news:il5tj0933ioq0hq94juu92stgkjveikcsi@4ax.com...

>
> The Doppler effect is not disputed. If the distance between the source and
> receiver is changing, an apparent shift in frequency will occur.

True, but there is an argument that in the case of a speaker cone being
driven by a complex waveform containing more than one frequency, the virtual
sound source is not the surface of the moving cone, it's the center of the
cone's motion, which is not moving with respect to the listener. There is
also the argument that the sound wave being radiated is NOT a case of one
frequency "riding" on another, it's a single complex gestalt, and as such
there is no possibility of Doppler shift occurring. This isn't particularly
Bob's position, it is mine, and being neither a physicist nor a
mathematician, I could easily be mistaken about either or both.

> Doppler Distortion states that since a speaker cone is moving back and
> forth, the distance between the source and receiver is changing, thus the
> Doppler effect takes place. In the simple example of a speaker producing a
> 50Hz signal and a 1000Hz signal, the movement to create the lower
frequency
> is the cause of the Doppler distortion of the higher frequency.

If there were two motive sources, this would be true. If you had a speaker
producing a 1000Hz tone and were moving the speaker back and forth at a 50
Hz rate, it would produce Doppler shift. However, if you are driving the
speaker with a single motive source containing both frequencies, then the
complex sound wave being produced would be a coherent single waveform and
not subject to Doppler shift because the 1000 Hz tone is not riding on the
50 Hz tone (like a whistle on a train), the wave is a complex whole
containing both frequencies which are fixed in relation to each other and
there is no relative motion between source and listener. The HF tone riding
on the LF tone is an illusion, this isn't a whistle riding on a train, it's
a diaphragm producing a single complex waveform. Again, this is my position.

> As the cone moves forward once to create the 50Hz frequency, it will
> oscillate 20 times to create the 1000Hz signal. I would assume you'd see
the
> frequency as rising. I hope I stated that accurately.

You did. but as I said, that's an illusion based on the train/whistle model,
which doesn't apply in this case. With the train/whistle model, you have a
sound source actually riding on a separate motion source, with a speaker,
you have one single complex motive source driving a diaphragm that is
producing a single coherent complex waveform. This may seem like splitting
hairs, but the difference is real and it's huge as it concerns Doppler
shift.

> Bob is making the argument that it's more complicated than that in part
> because speaker cone is making a sound wave for both the lower and higher
> frequency. The standard Doppler formula makes no mention of the movement
> creating a sound wave or even deals with an oscillating movement. Bob is
> looking to prove that physics involved in creating the sound waves alters
> the basic premise about Doppler distortion. Am I close enough, Bob?
>
> The experiment by Ghost, aka Gary Sokolich, essentially moved a speaker
back
> and forth. As expected there would be a Doppler shift. The problem with
his
> experiment is that the movement of the speaker (as opposed to the speaker
> cone) did not create any sound waves. It does not *prove* that speaker
cone
> movement as described above will create Doppler distortion. It does
validate
> the Doppler effect, but that's not in contention. He might as well have
had
> the train with the whistle stay still while the listener bungie-jumped
above
> it and bounced up and down.

Dead on Jim. I think Bob is seeing something that is much more complex
than Doppler shift and is only loosely related to it, in fact, Doppler shift
may only be a special case of the phenomonen he's seeing. He's calling it
"Doppler mixing" for want of a more discriptive term. I have a glimmer of
what he's seeing, but not enough to say more than I have so far.
In fact we're not in total agreement on my position on Doppler shift in a
speaker.

> Someone posted a formula for determining what one should expect to find
with
> Doppler distortion. So, it would seem you could set up an experiment with
an
> actual speaker producing the above frequencies and check out what
> frequencies are seen by the source. The mathematical predictions should
> include Doppler distortion and any frequency or amplitude modulations
which
> may result.

Unfortunately, it isn't that simple. this argument has been going on for
at least thirty some odd years and the best experts in the field haven't
proven anything either way, and no one has come up with an experiment that
proves anything either way.
The only thing I'm absolutely sure of is that the train/whistle model is a
separate, totally unrelated phenomonen that doesn't apply at all to a
speaker reproducing a complex musical waveform. Indeed, the operable term
may be "reproducing", an ideal diaphragm over a hole in the wall between two
rooms will reproduce an exact indentical copy of the complex sound source
wave in the second room, so there will be no Doppler shift introduced by the
diaphragm. Since a speaker would be driven by the exact electrical analog of
the complex source wave and will reproduce it exactly, just like the
diaphragm over the hole, so the speaker will not introduce Doppler shift
either.

> If the modulations do not coincide with Doppler distortion frequencies,
then
> in theory you should be able to measure the resulting frequencies and
state
> with relative certainty what frequencies were explained by what. If you
see
> other frequencies, you had better explain what caused them.

Again, it just isn't that simple. The best minds in audio have debated this
for many years without successfully proving anything either way, so its
unlikely that we'll do that here, but I think we've all learned something.

> And before you ask, no, it ain't gonna be me! Before all this started I
> thought oscilloscope was what they used to film movies, like cinemascope.
>
:-)
September 9, 2004 2:38:20 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

"Jim Carr" <jim@azwebpages.com> wrote in message
news:akP%c.78295$yh.28371@fed1read05...
> "Bob Cain" <arcane@arcanemethods.com> wrote in message
> news:chmah30ujn@enews1.newsguy.com...
>
> > This is getting sticky because it is _really_ hard to
> > predict what a typical speaker will produce as distortion
> > components. Well nigh impossible. Piezo's are at least as
> > bad. OTOH, the distortion products due to the speaker
> > itself are both minimized and made very predictable and
> > measurable in the case of a push-pull electrostatic which,
> > for that reason, is what should be used in the experiment.
>
> Interesting. I wonder if using something like 50Hz and 51Hz would be
better
> to use than say 50Hz and 1000Hz.
>
I don't think the frequencies really matter as long as there are two or more
of them. From a practical point of view, the frequencies must lie in the
range that the speaker is capable of reproducing.
Anonymous
September 9, 2004 2:53:13 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Bob Cain wrote:
> Not in detail. When looking locally at the effect of a slowly moving
> piston on its emission of a higher frequency tone, we have more dynamics
> going on than just distance modulation between piston face and a
> reciever very close to it compared to the wavelength of the LF
> component. The pressure is changing locally due to the LF action,
> although it can be considered constant for any given cycle of the HF
> tone, the temperature of the air is changing and the air is moving with
> the LF component of the piston motion. This also means that c itself is
> changing locally. When all of this is properly factored in, what comes
> out the bottom?

Well, I agree that there are probably other effects going on. Surely
some of it will depend on the speed at which the driver is moving.
If you have a speaker projecting a 1000 Hz tone forward from the
front of an aircraft, and if the aircraft hits Mach 1, then you've
got something more complex than doppler distortion going on. :-)

Anyway, I don't have the level of ability to come up with a mathematical
model of all that, but I really suspect the answer is going to be that
there are effects that tend to reduce doppler distortion, but they
are going to [a] vary as some function of the two frequencies involved
(assuming we are talking about two sine waves), and/or depend on
the amplitude of the driver's motion. In other words, I'd be surprised
if these other effects *exactly* cancel out what would otherwise cause
doppler distortion.

- Logan
Anonymous
September 9, 2004 4:31:54 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Jim Carr wrote:

>>This is getting sticky because it is _really_ hard to
>>predict what a typical speaker will produce as distortion
>>components. Well nigh impossible. Piezo's are at least as
>>bad. OTOH, the distortion products due to the speaker
>>itself are both minimized and made very predictable and
>>measurable in the case of a push-pull electrostatic which,
>>for that reason, is what should be used in the experiment.
>
>
> Interesting. I wonder if using something like 50Hz and 51Hz would be better
> to use than say 50Hz and 1000Hz.

How would that alleviate the eperimental problem of a
distorting driver pissing all over the signal you need to
measure in order to get a measure of Doppler mixing? To
look at any spectrum and claim that it couldn't be due to
driver non-linearities is specious unless the driver doesn't
have any.

According to the detailed conjecture that has recently been
put forward by Art Ludwig, which seems to be along the old
lines, there is no signal you can give a driver to measure
its intrinsic distortion so as to factor that distortion out
of measurement because it says that any signal given to a
driver is distorted somewhere between the piston face and
the air by his hypothetical Doppler distortion equations.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
September 9, 2004 4:35:29 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Porky wrote:


>>Interesting. I wonder if using something like 50Hz and 51Hz would be
>
> better
>
>>to use than say 50Hz and 1000Hz.
>>
>
> I don't think the frequencies really matter as long as there are two or more
> of them. From a practical point of view, the frequencies must lie in the
> range that the speaker is capable of reproducing.

It matters because frequencies that are close together are
going to be coupled to a reciever very nearly the same. To
see any signifigant Doppler mixing there must be a
signifigant difference in that coupling.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
September 9, 2004 4:58:19 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Porky wrote:

> True, but there is an argument that in the case of a speaker cone being
> driven by a complex waveform containing more than one frequency, the virtual
> sound source is not the surface of the moving cone, it's the center of the
> cone's motion, which is not moving with respect to the listener.

That's a good way to put it, but only if all components are
equally coupled. For example, a speaker emitting a tone
while swinging on a pendulum _will_ be seen as having a
moving source because the LF motion is not coupled to a
distant receiver.

> There is
> also the argument that the sound wave being radiated is NOT a case of one
> frequency "riding" on another, it's a single complex gestalt, and as such
> there is no possibility of Doppler shift occurring. This isn't particularly
> Bob's position, it is mine, and being neither a physicist nor a
> mathematician, I could easily be mistaken about either or both.

In the very near field of a radiating source this is true
but breaks down as you move away and begin to experience
frequency dependant coupling.

> If there were two motive sources, this would be true. If you had a speaker
> producing a 1000Hz tone and were moving the speaker back and forth at a 50
> Hz rate, it would produce Doppler shift. However, if you are driving the
> speaker with a single motive source containing both frequencies, then the
> complex sound wave being produced would be a coherent single waveform and
> not subject to Doppler shift because the 1000 Hz tone is not riding on the
> 50 Hz tone (like a whistle on a train), the wave is a complex whole
> containing both frequencies which are fixed in relation to each other and
> there is no relative motion between source and listener. The HF tone riding
> on the LF tone is an illusion, this isn't a whistle riding on a train, it's
> a diaphragm producing a single complex waveform. Again, this is my position.

And one, as you know, that I don't agree with. It doesn't
matter at all what kind of mechanical (as opposed to
acoustic) coupling exists among a stack of drivers, all that
matters is that the area of the last element be the largest.
What comes off the face of that stack, each element driven
separately, will be the same as what comes off the final
driver with the electrical sum applied to it and the others
not moving. In either case, it is linear superposition that
gets to the radiating face.

If, OTOH, you have a small radiator attached to the front of
a larger one, there will be a difference because of the
differing radiating patterns of the two drivers (frequency
dependant coupling again.)

> With the train/whistle model, you have a
> sound source actually riding on a separate motion source, with a speaker,
> you have one single complex motive source driving a diaphragm that is
> producing a single coherent complex waveform. This may seem like splitting
> hairs, but the difference is real and it's huge as it concerns Doppler
> shift.

I wish I could persuade you that it isn't a matter of
compound sources per se, it is a matter that the train's
motion is not coupled to a standing reciever while the
whistle's is, same as a speaker on a pendulum except that a
constant shift will be heard with the whistle and a slowly
varying, oscilating one with the speaker on a pendulum.
What they have in common that results in Doppler mixing at a
distance is a wide difference in coupling between the HF and
the LF motion between Tx and Rx.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
September 9, 2004 5:28:14 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Bob Cain wrote:


> I wish I could persuade you that it isn't a matter of compound sources
> per se, it is a matter that the train's motion is not coupled to a
> standing reciever while the whistle's is,

That was misleading. I should have said, "it is a matter
that the motion the train imparts to the whisle is not
coupled to a standing reciever while it's whistle is."

> same as a speaker on a
> pendulum except that a constant shift will be heard with the whistle and
> a slowly varying, oscilating one with the speaker on a pendulum. What
> they have in common that results in Doppler mixing at a distance is a
> wide difference in coupling between the HF and the LF motion between Tx
> and Rx.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
September 9, 2004 9:36:05 PM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

"Bob Cain" <arcane@arcanemethods.com> wrote in message
news:chp3gk0meb@enews3.newsguy.com...
>
>
> Bob Cain wrote:
>
>
> > I wish I could persuade you that it isn't a matter of compound sources
> > per se, it is a matter that the train's motion is not coupled to a
> > standing reciever while the whistle's is,
>
> That was misleading. I should have said, "it is a matter
> that the motion the train imparts to the whisle is not
> coupled to a standing reciever while it's whistle is."
>
> > same as a speaker on a
> > pendulum except that a constant shift will be heard with the whistle and
> > a slowly varying, oscilating one with the speaker on a pendulum. What
> > they have in common that results in Doppler mixing at a distance is a
> > wide difference in coupling between the HF and the LF motion between Tx
> > and Rx.
>
My little mental model says that there is no doppler shift in a single
speaker cone reproducing a complex musical waveform, but I'll readily admit
that my model concerns only the soundwave as it is produced by the cone's
vibration and doesn't take into account what happens at some given distance.
I don't think my view conflicts with what you are calling Doppler mixing,
since, as I understand it, that occurs with respect to distance and polar
orientation from the source. That requires a much more complex model that
the one I'm using, and I haven't yet come up with a satisfactory mental
model, but I do get a glimmer here and there, enough to believe that you're
on to something.
Anonymous
September 10, 2004 3:46:35 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Jim Carr wrote:

>
> All that aside, it still wasn't a speaker you were measuring.

I don't think he measured anything at all. I think his
claims are entirely fraudulent as is everthing about him.

> In your mind
> I'm sure you think you simulated a speaker. Hell, in your mind you simulate
> a decent human being, but we know that's not the case.

Wish to hell I'd said that.

I wish to thank Sokolich profusely for refering me to Alan
Pierce's book. The answer is completely contained in it and
fully agrees with my analysis.

I just wonder why Sokolich didn't bother to read it.
Perhaps he can't understand it. For a refutation of Art
Ludwig's conjecture and a specific reference to where
Pierce's solution is in his fine book go to:

http://www.arcanemethods.com/Doppler/No_Doppler.html

I think this debate is at an end. Somebody please forward
the above link to Art Ludwig. He said he has no more time
for me here and I think he went home.

Time, perhaps to move on to formulate a true general theory
of Doppler mixing.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
September 10, 2004 4:05:54 AM

Archived from groups: alt.music.home-studio,rec.audio.tech,rec.audio.pro,alt.sci.physics.acoustics (More info?)

Porky wrote:


>
> The experiment you posted here had two motive sources, the disk was
> driven at 10 KHz, while being moved at 50 Hz by another source, which is
> based on the train/whistle model, and Doppler shift will occur. As I've
> explained repeatedly, this analogy isn't accurate for a diaphragm being
> driven by a single complex waveform and producing a single coherent complex
> soundwave. If you can't see the difference, then you'll never understand it.
> I guess it just goes to show that education is not an adequate substitute
> for intelligence.

Now, now, Mike. You are wrong about this. :-)

> The only thing worse than an arrogant, pompous stuffed shirt with porcine
> paskat for brains is an arrogant, pompous, stuffed sheet ghost with
> ectoplasmic equine excrement for brains. Go haunt some other group, jerk.

But not this.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
!