I bought an overly expensive RCA interconnect today ($19-20). I replaced a trusted and time-proven skinny one that came with some piece of electronics at some point in the distant past. New one has small arrows on it, or what seems to act as arrows. I tried them in both directions and there was no difference in sound. Not to practice audiophiliac blasphemy, I conducted this experiment with no blinding. I knew what I was changing and in what way. I am still not sure why that is better than single or double-blinded testing in these woods, but so be it.
This thread is about speaker cables and my experiment was about interconnects. Both are, in general, wires.
The conclusion is that wire directionality does not matter when dealing with wires of relatively short length (50 cm). Amen.