It really depends. I recently upgraded speakers, the old pair sounded much better biwired. Upon setting up my new speakers with the same cables they sounded terrible. I was obviously dissapointed when my old speakers sounded a lot better in back to back comparisons. Then I set them up using a single wire and they now sound an order of magnitude better than my old speakers. I also upgraded the cable to Harmonic Tech from Kimber 8tc and the improvement is dramatic. The true test is through back to back comparison.