Ok, I like my Kenwood HTB-705DV. It fills my room, which is pretty small. The only thing is, I would like to get a better subwoofer. This presents a problem for the HTB-705DV, because it has the subwoofer amp built into the receiver. Is there a decent or better-than-decent sub out there which I can get to replace the non-powered subwoofer in my current system, or do I have to get an RCA conversion kit or something? Thanks for any help/info.