I actually did a careful experiment. I was a non-believer. and Sean, formerly on Audiogon, loaned me a set of cables to test.
I was using AWG12 zip cord. I forget exact;y what the test cables were, but they were a well regarded "exotic" brand.
I set up two identical Dynaudio speakers, close together,one with my zip cord and the other with the exotic cable. I connected the same (mono) signal to each channel. Now, by using the balance control on the preamp I could listen to one wire, and then the other in quick succession.
After quite a bit of listening I concluded that the exotic wire sounded very slightly better than the "junk" zip cord. I am not sure I would pay much for the difference. Nevertheless, when I reconfigured my power amps to monoblocks adjacent to the speakers I did spring for exotic wire. I have no idea if it was necessary, but the wire length was so short that the cost was not great.
