Stfoth 8-2-2017If we assume as your question posits that all cables are inherently directional, IMO the key to obtaining an answer would be obtaining an understanding of **why** such an effect may occur. And as I said in an earlier post, IMO the least implausible explanation I have seen is the one stated by Audioquest.
Perhaps this has been adequately and succinctly discussed elsewhere, but, assuming all cables are inherently directional with sound differences from one way to the other, what might be some reasons someone, with a good trained ear with a highly resolving setup and with no skin in the game, wouldn’t be able to hear a difference?
I doubt that any of us are in a position to say conclusively one way or the other whether the effect claimed by Audioquest is likely to be great enough in degree to be audibly significant in some or many systems. But let's assume that it is. The explanation revolves around electrical noise. Sensitivity to electrical noise that may be present will be highly dependent on the specific designs of the components, cables, and system that are involved, on how AC power is distributed to the various components, on how the components and cables are physically arranged, and on the noise environment at the particular location. And it will be highly dependent on the spectral composition (frequency distribution) as well as the amplitudes of whatever noise may be present.
As I said in one of my previous posts in this thread, noise effects tend to have little if any predictability, and tend to be highly system and even location dependent.
It should be noted, finally, that none of these factors have any particular correlation with the sonic quality or musical resolution of the system, or with the hearing acuity of the particular listener.
Regards,
-- Al