So as time went on and my main speakers changed the PSA didn't fit the bill anymore, with its 15 inch driver music was always a bit muddy. so I hooked my REL t1 back up and it was like magic! fast, tight and very musical but lacked weight. so I ordered two REL t9's which should fit the bill. after reading many articles about subs I think the majority of people agree, get two subs or get none. After all we don't buy one speaker, right?