I have a 2 channel amp, a 4 ohm SVC sub. I can't get the subwoofer to work. I'm almost positive the sub is hooked to the amp correctly. But does it need to be hooked to the head unit? The head unit has one RCA phono cable for the subwoofer, but the amp has two female ends for these cables but they say Low In (L&R). It is a American Pyramid PB1000 Amp. It was purchased at a pawn shop, so I don't have any other info on it. Can I get the sub to work with this? Sorry, its kinda hard to explain.