On Tue, 17 Aug 2004 04:56:40 GMT, Randy Yates wrote:

Bob Cain writes:

Randy Yates wrote:

Proof by assertion?

Sorry, Randy. I see nothing but proof by assertion from the
supporters of "Doppler distortion." It shouldn't be incumbent on
those that observe that no predictive theory exists to prove why it
doesn't, although I've been trying, it should be incumbent on those
claiming that it exists to produce the predictive theory. Have at it.
This isn't string theory. If it's there, a precise model should
almost fall out by inspection.

If by "predictive theory" you mean a theory by which this phenomenom
can be predicted, then I must ask if you are blind.

That's not the problem here. Bob "believes in" Doppler theory when
it's a whistle on a train.
Bob refuses to see that the source of soud is the speaker cone,
moved back and forth by the voice coil, thus the "source of sound" in
a loudspeaker driver is moving.
Bob claims and believes the sound source is a 'fixed source'
relative to the driver's frame. I imagine this comes from multi-way
loudspeaker system design, so that driver positions can be set
relative to each other so that they are "phase coherent" or
"time-aligned." (Off topic, both of these are probably registered
trademarks of speaker makers from the '70's) This model is a good one
and certainly works for this purpose, but like many models, it doesn't
work for all situations. Specifically, it doesn't predict doppler
distortion caused by cone excursion.

I have stated it
several times in several different ways. I have cited a reference for
it (Halliday and Resnick). I am assuming you are familiar with the
theory. Is that assumption invalid? Do you want a rehashing of the
theory of the Doppler effect? Do you want me to transcribe my Physics
text into a usenet news article for you so you don't have to go to the
library and check one out?

I suspect Bob knows it as well as you do, but he's just missing it
and has some other idea in mind when it comes to a speaker cone.

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