how big a speaker can you put in an 11 x 11 room?

I have responded in another thread on the same issue in that I am a big fan of small speakers(either small towers or bookshelf speakers on stands) + subwoofer in a small room. A large speaker in a small room often sounds like crap most of the time. Having said that, I have seen a guy having the Marten Coltrane floorstanders in a 9'x13'x8' room which is an exceptional case. However, that room has got some real serious treatments and planning gone into it as all the wall surfaces which include the ceiling have been treated.

Dgad's advice may only come in useful if the speakers are meant to cater for a strong 100,000 crowd of a large rock concert.

01-29-09: Raquel
The other posters are way too polite - big speakers sound like shit in too-small rooms.

I guess the post I've written earlier isn't too polite either? :-

01-27-09: Ryder
A large speaker in a small room often sounds like crap most of the time.