I have Arc Audio 8" Sub, I am very happy with its SQ, very musical atleast to my ears. It didn't need a ton of power (150watts) and the enclosure size was small 0.35ft^3, list price is $169. I had a Boston Acoustic Pro8.5's previously and in my setup this sounds better (and it was a lot cheaper). I also considered ID's. I would have considered a 8w7, but the mounting depth is really deep.