No one actually knows how to lculate what speaker cable they need

Mr.  eichlerera

I'm sorry to kill your impression of skin effect on Audio frequencies.
The figure (at the AWG table) refers to full power at x frequency.
An other way to look at that, is that thin cables have low current capacity at DC, so it is close or identical to that in all Fr. Thick cables, that can conduct 10th or hundreds of Amps at DC, are a bit less of higher Fr.
But even so, if you look into Audio energy vs. Fr., the most power is at the lower Fr.: under 1 kHz. most of the stuff over 10 kHz are harmonics that are of very low energy. So skin effect is not for Audio, It mostly present at RF and very high frequencies, at high power (Radar etc'.).

b4icu,

How do you believe the signal propagates through a speaker cable?

As in any other cable. No particular significance of any type, at Audio freq. 
The only characteristics I found significant, is the cable resistance vs the Amp's DF. 
It works all the way up to the calculated value (improves sound) but do not improves above (thicker than calculated).

No.
I'm asking how you think the actual signal travels through the conductor.

Hi
Google it up. I never thought it matters, after all, we use it, on daily bases, in every electric device on the planet. For some reason, audiophiles tend to think that it is special in their sound system. Well it’s the same. Many of those are life saving equipment, military, space, measurement devices, cellphones and more. None ever tend to go, where audiophiles go: BS land.