Go to AdireAudio.com. Look up the sub named RAVA. Do a search on AudioAsylum.com for the RAVA sub as well as Hometheaterforum.com. Become impressed. Become excited. Purchase the sub. If you don't like it you can return it within 30 days (check that out for sure). It has received rave reviews across the net and the owner and creator Dan Wiggins is highly respected in the subwoofer and speaker circles.
Good Luck.
Good Luck.