I'm running a 4 ohm speaker with biwiring capability...add to that a sunfire woofer and yes, biwiring does "add" to the sound quality. If biwiring didn't work, speaker manufacturers wouldn't do it, and save money..now, it has to be a true biwire in the speaker....the Dantax's are. The biwire bypasses the crossover...It does provide and easier route for the receiver to run a 4 ohm load. Theoretically...you should be able to run 2 4 ohm systems on A&B and have good output and definition....but you will pay the price on equipment fatigue. Some of which is attributed to heat buildup. My main system is run with Boulder amps and MBL loudspeakers. Biwiring these is a turkey shoot....They are designed for a single input even though they have biwire terminals. The MBL's however...are biamped, which provides a far more measurable benefit in sound....as always in audio, if it sounds good...do it!!!