I am something of a sceptic when it comes to speaker cables, but I have tested a few mono CD tracks using two different cables: - a blue Black Rhodium ATS 200 bi-wire and - a Chord Carnival biwire (I think: it is a transparent cable with an Orange stripe down one side; each of the 4 cables consists of 6 silvery solid strands mixed up with what looks like plastic separating strands (one thick central and 6 or so thin ones). Both are about £10/m. The speakers are ProAc Response Hexas. Their main characteristic seems to be a superb 3D effect: you can almost touch the solo drumkit player in one track. I started with the ATS 200, but found the sound a touch duller/more recessed than I expected. I was rather hoping that it was just my imagination and there would be no difference betwen the two cables, as stripping the Carnival cable is a fag: it's thick and you have to remove all the plastic bits. However, to my surprise, playing a few mono CD tracks (speech, music) and listening to one and then the other alternately convinced me that the Chord Carnival was more capable. It gave a slightly more realistic, richer (more musical?) sound, and certain details, such as the clicking sticks against each other was more clearly discernable. I used the direct stereo mode of the Yamaha amp to bypass all of its adjustments. Just thought I would share some empirical evidence.