As I dealer, I had one too many customers say: "My room’s not big enough for a Home Theater!" So, I bought a 30" x 30" British phone booth (replica, the real ones literally weigh a ton) and put a full 7.1 surround system in it -- custom enclosures, infloor subs, etc. This thing rocked!!
After that, when people said the familiar: "My room is not big enough for home theater!", the qualifying question was: "Is it bigger than thirty by thirty inches?"
Small rooms have their challenges (and benefits). Great advice here from guys who know a lot about the subject. Best of luck.