And once again I showed you that for the maximum possible different position of the high frequency signal in relation to the woofer position the delay difference is only 0.06 ms. If we had drivers with 40cm excustion that diifference would become 1.2 ms and then could be relevant, but such a wide band driver would have other much more problematic issues.
I already told You that the group delay does not originate in the cone excursion. I have simply two bursts of which one carries a lower frequency package, the other carries a higher frequency package. I'm pretty sure that you personally get the idea of such frequency packages (
https://linkwitzlab.com/mid_dist.htm, but shorter).
Maybe I have a mixing console, a digital sound workstation, whatever. I'm pretty much able to mix the two bursts together. And I can mix them together into one "signal" so that the high frequency burst occurs first in time before the low frequency burst (a). I mix another signal, in which the two occur at the same time (b). Yes, we can do that today.
In result I have two different signals, bear with me.
Would the two sound different to a human's hearing apparatus, when converted into sound by a loudspeaker? The proponents of a so called "time correct" speaker say "sure, because of the time difference".
My question is: could it be that it is not the time difference, but the non-linearity of the speaker that makes the difference? Obviously, sorry for colloquial language, the speaker has a lot more work at a time, if the two packages fall into the same time slot. If they spread out in time the speaker has less to do, because the workload is distributed.
Now comes the hard part. Such a shift in time can occur within the speaker itself. Signal (b) is fed in, but the cone, sorry for colloquial language, moves like (a), and because of that the sound waves would look as if signal (a) was fed into an ideal speaker. Since the non-ideal speaker has that extra group delay, it would more easily produce the sound waves, which might sound different. Hard to grasp, I know. But such a situation might occur with even a tiny group delay of just 5ms between bass and mid-frequencies.
('Think it doesn't make sense to ask for pre- and post-masking within the human ear, still in discussion? 'Think most of you shiver when I show you how viciously cone excursion modulates the acoustic output. )