Interconnects, some have directional indicators, why?

The audio signal goes in with positive wire and backs out with negative wire.

That is not correct. During one half-cycle of each of the frequencies that is present the current corresponding to that frequency flows in via the positive conductor and out via the negative conductor. During the next half cycle of each of the frequencies that is present the current corresponding to that frequency flows in via the negative conductor and out via the positive conductor. The directions of the current in each conductor continue to alternate during successive half-cycles. Meanwhile, energy is transferred in just one direction, from source to load (assuming the load is resistive), with the alternating flow of current through both conductors being essential to that process.

BTW, the "positive conductor" is often referred to as the "signal conductor," and the "negative conductor" is often referred to as the "return conductor" or "ground conductor," but the electrons and the energy that is being transferred don’t care about names.

Regards,
-- Al

@geoffkait 
the cable manufacturer listens to cables made with the first wire taken off a new large spool of wire to determine which direction sounds best. The rest is easy, no?
 

Something tells me you're just making stuff up here. I don't believe that for a second.

timrhu

@geoffkait
the cable manufacturer listens to cables made with the first wire taken off a new large spool of wire to determine which direction sounds best. The rest is easy, no?

"Something tells me you're just making stuff up here. I don't believe that for a second."

Would I kid you? 

helmingway
And now we have claims of photons travelling down pieces of copper. I guess that would be responsible for creating a truly holographic imaging experience. No wonder this topic always sparks controversy.

All electromagnetc waves are comprised of photons. I.e., not only is visible light on the electromagnetic spectrum made of photons, but also X- rays, gamma rays, HF radio waves, SHF radio waves - everything on the electromagnetic spectrum. Including audio signals. They’re all photons.