I would appreciate recommendations for my situation: I have my HT in a 16 x 18 x 7 1/2h room, average acoustics. I am using AR3a's (yes, still have them!) as the mains. In their day, they were considered very good, including @ bass end. By my judgement today, they are just OK. I don't want to spend a lot of money, but would adding a subwoofer in the $150-200 range be worthwhile? I see the Sony SA-WM40 generally praised here, especially if polyfilled. Would that be a good choice? Thanks much.