I owned these speakers for 2+ years and tried the biwiring option once and heard no difference. I will add that the biwire cable was a different brand so the comparision may not of been very valid. BTW the SHL5's are some of the most enjoyable listening speakers on the market. Put the music on an enjoy. I also found when I upgraded my CDP, amp, preamp & cables the Harbeths would always improve. Even though the SHL5's will sound great with a moderate ss amp don't hesitate in trying 150 - 250 watt ss amp.