let me see if i understand this correctly..
on the paramaxx system the subwoofer has a power cord, it has speaker outputs as well as inputs for audio? it sounds like a self powered set and honestly those are not meant to be hooked up to a receiver. receivers are generally meant to function with passive speakers not active speakers. yes, you could use speaker to line-level adapters but its mostly pointless. if your subwoofer and already has inputs for analog audio (6ch analog in) it would be easier to use something other than a receiver for hooking up to it with multiple sources.
if i'm not understanding you right it would help to provide photos or list what connections you have on the sub.