Most subs can be hooked up 2 ways. There is an RCA plug un many recievers that is for low frequency effeact (LFE). This is a special output for the sub-woofer itself. It is a single output on a reciever, but is normally split with a "Y" splitter to the two sub inputs. It still only carries one signal. The other hookup option is to hook the front main speaker outputs from the reciever to the sub, then hook the speakers up through the sub's l/r output terminals. This allows the sub to use the standard main speaker signal, and create the bass for that. As both signals are a bit different, which is the normal or preferred way of hooking up your sub. Which gives the best results, the LFE input, or the pass-through of the main speaker input?