I have an 1100 sqft room and sit 7' from the front... Audyssey surprised me with

M22s: Small / 40hz
QS8s: Small / 90hz

I mean my M22s are close to the wall (3" ish) but 40hz? I don't think so. I bumped the M22s up to 80 and the QS8s to 100. Overall though, I'm happy with Audyssey's effect in my room.

snazzed

M22, VP150, QS8 <--all v2
Sub: Outlaw LFM1-Plus
Denon AVR1910, Sony X900-65"