Okay, I'll take a stab at it. If the wire is drawn thru the die in such a way as to align the molecules so that electicity flows better in one direction than the other, as Bob B. so eloquently point out, then it has a "phasing" orientation, just like a speaker does. A speaker operates on AC, but it is clearly marked + and - for phasing. Perhaps the wire is molecularly oriented to better carry the signal in the "drive" direction, and less oriented to go in the "reverse" direction. This could have some effect on "back EMF" generated into the amp, by the drivers, because the + terminal is connected to the amp's output device, and the - terminal is connected to ground. And it could also have some effect on the perceived "speed" of the cable on transient response.
How does that sound for a theory?
How does that sound for a theory?