I'm thinking about building a low cost 5.1 system with 5 NHT superzero xu's. I've read that these can be somewhat finicky to set up without a decent sub. Does anyone have any suggestions on a good low cost sub that would complement these speakers? Their usage would be about 90% HT. BTW, my room is a carpeted basement 21' by 13' with a 7'-4" ceiling. Would a low cost sub like the Sony sa-wm40 do them justice? I'm also considering the Yamaha YST-SW305 and the Velodyne VX10. Or, am I simply asking to much of these speakers to fill this size room? Any opinions would be appreciated.