I'm sure we have all read time and time again that one should route all speaker and signal cables away from mains cables to avoid any chance of picking up interference. But in reality, this is sometimes unavoidable. My current system, consisting: B&W 600 S1 speakers and a Sony DB940 AV amp is currently laid out such that the rear speaker cables run along side 240V mains cables. I do hear hissing occasionally in the rear channels only, but is this really due to the mains cables, or more likely due to the known problems with hiss on this Sony amp? I have been unable to isolate the speaker cables from the mains cables as yet to ascertain this, just wondered what the experts out there thought. Is there any means of shielding the speaker cables if indeed this is the problem? Thanks Andy P.