I need to know which will hit harder. One 15 inch HX2 or 2 12 inch HX2s. And where is the best place to buy one? I've been looking at Caraudiocrazy.com and they have some decent prices, but there is probably better out there. I also would like to know if my Power Acoustik 1800watt amp is worth keeping. I could possibly pawn it off for 400 to someone who doesn't know.