I am also in the market for looking for a sub. Although I am an Axiom loudspeaker fan having the M22Ti and QS4 I opted out of the Axiom subs. I am down to the Mirage BPS-150i (bipolar sub), The Difinitive Technology ProSub100TL and the Energy Encore 8 Sub. All 3 go as low and the Axiom and are in the same price range. I think the Mirage BPS-150i will become the outcome only because of its tight dual driving bass driver. it has greater bass extension without being boomy. It is actually tight but fires in two directions. It is a BIPOLAR subwoofer. It also has a MOSFET amplifier which I have seen in some really high end subs.
http://www.miragespeakers.com/products/currentproduct/bps/bps150/index.htm
Saturn
