I ran into a problem. I have a receiver with surround sound connections and a B channel connection. I hooked the surround sound up and also hooked in whole house distributed audio to the B channel. I get distorted sound even if I turn off the B Channel with the A/B switch on the front. Do I have to have a multi room multisource receiver to do this. By the way, If I took out the impedence matching volume control and only drove one pair of speakers on the B channel it worked fine. Any ideas? Thanks