I'm hooking up a Klipsch 500 Home theater system to an older Sony receiver. The receiver doesn't have a sub output. The sub does have a speaker level input for speaker wires, but no output. I'm able to get the subwoofer working by using the RCA Line in jacks, from the Tape Out channel of the receiver, but I have no level control on the sub, so when I mute it, the sub is still outputting audio. I tried running speaker wire to the Speaker Level Input of the sub from the b channel of the receiver, and my L R and center on the A channel of the receiver, but both A & B only gives me audio from the sub, and not the speakers.