Updating my home theater system I am intalling a HK AVR 325. My former Sony STR-D1015 receiver used positive & negative wire connectors (actually speaker connections) to the (powered) bose sub which also accepted positive and negative with RCA connectors. The HK has only a single RCA sub output plug that is supposed to go to a "line-lever input of the subwoofer. I have no line-level input. How do I connect from one plug on the receiver to two plugs on the subwoofer? Perhaps a radio shack adapter? If it matters I also have a dual RCA to 1/8" plug for this sub cuz it couple also be connected to a computer sound card. (there is also a female, "system control", 1/8" plug connection but I have no idea what that is for) Thanks!