HEy all, i own the marantz pm7200 amp and im thinking of getting a sub to plug in. However ive done a bit of research and i cant seem to find a consistent answer. So i kind of have 2 questions, 1, what do people mean when they say "active subwoofer". 2. The sub I am thinking of getting has , hi-level speaker wire connections Input and Output, it also has low-level , Input and output RCA jacks. Now the question is, what are my options for connecting the sub to my amp?. The amp does not have pre-outs. I have also heard that plugging the sub in series with the speakers tends to lower the quality of the output to the speakers? The amp also has jacks for a second speaker system, however this drops the impedence to 16ohms, a loss of power?? as when running a single speaker system the impedence is 8 ohms. And finally, could the sub be plugged into the processor input/output jacks on the amp??.