Just setting up my new system, ive never had a powered sub before and the instruction book is no help! There are 3 sets of 2 connections on the back of the sub 2 of them are like normal speaker terminals you find on the back of an amp 2 black 2 red, being the left and right and plus and minus, marked High Level Input. What are they for? The other two connections one of which i think i need to use are marked Low Level Inputs, the white one is marked Left and the red one is marked Right/ mono. Do i use the red one? Im guessing the white one is if you are using 2 subs? Please help want to get this up and running.