>>> For music I would say a sub is optional. I still often turn the sub off when listening to music. If your room really is 2200 sq ft, though, I would probably leave the sub turned on so the speakers don't have to work so hard.

Wouldn't it depend on the song as well? I have 16'x13'x9' room with M60s as main and EP500 (overkill I know ). On some music I listen to, having the sub on didn't make too much of a difference if at all but on some others it made a pretty significant difference. Regardless, I keep the sub on all the time now though cause I'm too lazy to turn it on/off everything I switch from watching movie to listening music