On Mon, 16 Aug 2004 21:57:16 -0500, "Porky" wrote:


"PenguiN" wrote in message
. com...

If you still don't believe that this scenario validates the
train-whistle analogy, why not make the bass waveform move at the
speed of, oh say a train, and have the high pitched signal on top of
it be, oh say the sound of a whistle.

Doesn't apply, the train and whistle are supplied by two separate sources of
energy.

Have two amplifiers, one for the low frequency connected to the
speaker through an inductor, another amp outputting the high frequency
connected to the speaker through a capacitor. Thus the low and the
high are supplied by two separate sources of energy.

Actually, isn't the train whistle powered by steam from the same
boiler that powers the wheels, moving the train? What's up with that?

But seriously, for Bob and other anti-doppler-distortion folks, how
does cone-and-frame movement cause doppler while cone movement only
does not? What is it about the frame that causes doppler?

If you put the speaker on a shaker table, run 1kHz and 50 Hz
through the speaker, move the shaker table at 50 Hz opposite the phase
to the speaker so the cone only moves at the 1kHz rate with respect to
the air, will it generate doppler distorion? According to my
understanding of Bob's position, it should.
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