Hello, Wanted to see if anyone had any suggestions for a subwoofer for my HT audio system - B&W CC6, 602's as main's, 601's as rears. I know what B&W recommends, but are there less expensive alternatives that would "match" w/this setup? Mostly movies 80/20, room is about a 18X20 w/very high vaulted ceiling. Usually not extremely loud volume levels. If you need more info to answer please let me know. Thanks.