So what would AC do to a speaker in your understanding? Why would you prefer DC with modulation?
To limit OT: the signal in case of music is actually AC. You're correct with the fact that the properties governing possible differences between cables with respect to music is primarily the impedance (and only to a lesser degree the DC resistance). Nevertheless I seriously doubt that switching cables makes a major difference, especially one worth a somewhat substantial amount of money. And No: I won't discuss that any further ;-)
Correct further No discussion on cables . However do you actual think that AC passes any further than the mains transformer and rectifier or switching mode power supply in amplification equipment??? Do you really want your speaker cones to try and go backwards every half cycle??? Just Google it if you think I'm wrong.