I am nearing the end of finishing my home theater and hooked up the equipment this weekend. It is going to be a 7.2 system with the 2 subs being in a front corner and an opposite rear corner of the room. I only hooked up one sub which is the front. I get a terrible hum out of it. When I ran the 12 gauge, CL2 rated wire for it, I was careful to stay away from other electric wires. The distance of that wire is a little over 40'. Is it a distance issue because of the "Line Level" signal? Any suggestions or thoughts?