my brother had a set up like this in his 280z it was awesome.he had 2 12's in one box but the subs were mounted together with cones facing each other one was in the box the other inverted(magnet up) and set out of phase so when one pushed the other pulled that way they would not slam into eachother.this was proably one of the best sounding systems as far as bass goes ive heard if not the best with only 2 12's and a fairly small amp.