Porky wrote:

So, anyone want to describe a test procedure that can be done with
equipment that at least some of us are likely to have access to, and see if
everyone will agree that it's valid and that it will measure Doppler
distortion while excluding any other form of distortion that could be
mistaken for Doppler?

I have suggested one that would be definitive and free of
any extraneous effects. While not cheap or generally
available, this is about the _only_ experiment that can
isolate distortion that might or might not be occuring at
the air/piston interface which is how "Doppler distortion"
is described. Put a mirror at the center of the cone and a
laser interferometer at the position of a very linear
microphone. Drive the speaker with the classic two tones
that are supposed to most simply evidence the effect.

If the signal that comes from the microphone has a spectrum
that contains things that are zero in the spectrum of the
laser interferometer then there is real experimental
evidence for "Doppler distortion."

Mackie has or once had a laser interferometer such as what
is needed that they used to find out what was happening at
various points on a tweeter dome.


Bob
--

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

A. Einstein