I think JL Audio, while good, is expensive for what you get. If possible, two small subs are better than one large for your use, as it will help to minimize room modes. There is a great deal of information available about the benefit of multiple subs, as well optimizing setup.
Depending on your ability to place subwoofers, the Audio Kenesis Swarm may be a good option and in your price range.
http://www.audiokinesis.com/the-swarm-subwoofer-system-1.html
Depending on your ability to place subwoofers, the Audio Kenesis Swarm may be a good option and in your price range.
http://www.audiokinesis.com/the-swarm-subwoofer-system-1.html

