It is hard for me to believe that you don't know that a
predictive theory is one for which there is a mathematical
model which can predict, with accuracy, the results of the
kind of hypothetical situations that are being bandied about
in order to compare measurement to theory. Where is it?

Any book on physics has a section on Doppler effects. There are two basic
formulas -- one for which the velocity of the signal varies with the velocity of
the observer (eg, sound) and one for which the velocity of the signal does not
vary with the velocity of the observer (eg, light).

It's a trivial matter to compute the velocity of a driver cone moving at a
particular frequency and excursion. You can then easily compute the frequency
shift of a HF signal being reproduced by the cone.

I'm bothered by all this arguing, because I've repeatedly given clear, simple,
non-mathematical explanations of what's going on. Yet there has been neither a
consensus that they were correct, or a clear refutation of them.

The purpose of "argument" is to arrive at the truth, not to stubbornly defend
your present point of view.

I can't believe I'm the only "intelligent" person in this group with any real
insight into this issue.