I'm looking for a powered subwoofer that will take LFE from my receiver (Yamaha 573) under $400 (ideally under $300). Not totally sure on room size, but say 20x20 with 8' ceilings, no treatments. Typical 5.1 setup with inwall speakers. This is for casual home theater use, not music. I'm not looking to knock pictures off the wall, wake the baby or piss off the wife - just complete the setup.