"Phil Allison" wrote in message

"Jim Carr"

With that said, help me out here. I can't get myself away from the
assumption that since a speaker diaphragm has a throw of a certain
distance, then the waves started by the diaphragm may be started
from any point in that throw. As such two waves which are created a
certain time apart may end up traveling different distances to reach
my stationary ear, thus a Doppler shift.


** A time delay or advance is just that - it is not Doppler. Any
such delay or advance depends solely on the position of the cone -
not its *velocity*. If a cone is displaced by 10mm, that will
introduce a time error of 29 uS or a phase shift of 50 degrees at 5
kHz.

Any attempt to measure Doppler frequency shifts must allow for this
- most have not.

That's because this time shift, more specifically the time rate of change of
this time shift, is the cause of Doppler.