Arny Krueger wrote:

"Bob Cain" wrote in message


Randy Yates wrote:


"*IF* a system is linear, then it will not exhibit the Doppler
effect" is a true statement. However, get this:

T H E S Y S T E M I S N 'T L I N E A R !!!!!!!!!!!!!!!

Well, Randy, many people are saying that it is and produces
FM distortion anyway.


That could be both true and confusing, no?

No.


**** you, and I say that with all due respect. The system
here is everything from the face of the piston on out.


Out how far? Until we get to the receiver, there is no Doppler distortion
from that piston. Once we get to the receiver, there is Doppler distortion.
But judged all by itself fixed in space, the receiver can be
distortion-free.

Not even sure what you are saying here, sorry.



Nothing that occurs before that can be contributory and must
be eliminated in some way from any experiment designed to
catch Doppler at work.


It would be nice to eliminate that, but in the real world of acoustic
measurements...

I've offered one way to eliminate most of it.



Again, give me a mathematical expression which describes in
a quantitative way what should be measured at a distance
from that speaker as a function of the motion of that speaker.


Asked and answered, but it takes a little reading in standard references.

Please do so and provide theoretical support of your
proposed phenomenon. As always in science, that is on you.


I sincerely hope no one will say that it isn't
required because you see evidence of frequency modulation.


Where else might that FM come from?

The system that preceeds the piston/air interface.


Bob
--

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

A. Einstein