hey guys, reasonably new to A/V stuff, but a few months back I picked up a Yamaha receiver off these forums which has been running absolutely awesome in a 6 channel set up in my room. Anyways I'm in the market for an active subwoofer to go along with it. I'm wanting something with a bit of boom as I listen to a bit of electronic music and will also watch movies with it. Budget is $300. Don't mind if new or used. Recommendations please!