Interconnects, some have directional indicators, why?

Atmosphere's quote above perfectly explains how directional wiring would hurt the sound. The current is alternating back and forth, not flowing downstream. His diode analogy is spot on: if the current flows better in one direction, it is restricted in the other; therefore, directional wiring will absolutely make the sound worse. The argument that just grounding one end sounds reasonable... or would, if anyone would explain why the grounded end hooks to the source, rather than the input of the amp or preamp. Of course, no one has mentioned this.

+danvignau The shield should be connected only at the source end so that any interference that is picked up by it is reverted to the source and not transferred to the input device. This lowers the susceptibility to interference from electromagnetic signals in the surrounding and therefore improves the signal integrity. One exception is microphones where the shield should be connected at both ends so that the casing of the mic is grounded. The same applies to turntables/tone arms and battery operated equipment if no separate ground connection is used.

The shield can thus be considered as an extension of the source units cabinet.

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.

  kraftsound
Linn K20 / Naim Naca 4 speaker cables are directional due to a burn in process at the factory. If they are connected the other way around they will adapt to that and after a couple of weeks they will sound the same as before. There is a small audible difference.
If this is true also for other cables there is no actual inherit preferred direction in the cables

As I mentioned in previous post, the direction of metal cable is physically made and the sound doesn't change with the length of time. I heard sounds of many 40-50 years old metal wires in vintage gears melts like butter (in sound) in 1~2 minutes.

danvignau
The current is alternating back and forth, not flowing downstream. if the current flows better in one direction, it is restricted in the other; therefore, directional wiring will absolutely make the sound worse.

The current may be as you say, but the audio signal is not as you say. The audio signal goes in with positive wire and backs out with negative wire. In RCA IC, the negtive wire in correct direction is as important as the positive wire. The quality and thickness of wire in relationship between + and - wires change many things especially the speed of sound and rythm.

The audio signal is not flowing better in one direction but behaves differently in different directions. Typical sound of wrong direction wire is hot, grain, forward, no focus with wide sound stage (like out of phase). I know some super expensive speaker brands use all their wire opposite direction to make illusion of huge sound stage (out of phase).

Alex/Wavetouch Audio