Why are big speakers in small rooms bad?


I'm moving shortly to a new house and a new dedicated room that is 11x15. I was hoping to use an old pair of PSB Goldi's that are, no doubt, a bit large for that size of a room.

My question is, what are the reasons behind big speakers being a no no in smaller rooms? I've heard that the bass will overpower the room. If so, then why are people recommending monitors with a sub for a small room? Is it simply because of more flexable placement?

So, if you're able to place your speakers anywhere in the room and apply suitable acoustic treatment to the room, what are the physics behind the universal disdain for large speakers in smaller rooms? Not tiny rooms mind you, but say a 150^2 ft. room vs. a 300^2 ft. room. All rooms have nodes and other problems, is it just easier to treat a large room?

Thanks.
superfund
So what I'm hearing is that driver integration for near field listening and flexability in speaker placement for flat bass response are the 2 most critical issues here setting aside most fixable acoustic space problems.

If point source driver integration is a primary concern in a small room, do full range planars and stats do particularly well?

I recently purchased CARA and will be modeling and playing with room designs. There are so many variables to work with that I didn't immediately consider; like driver dispersion and integration...

I originally asked PSB months ago about recommended room size for the Goldi's. They stated a value, if I recall correctly, of about ~220 ft^2. This seems almost silly to me, in light of the previous discussions, to suggest a room area rather than generic dimensions and listening distances. Or did they just tell me that as a quick and easy answer?

My thanks to everyone for their public and private replies.
I'll be sure to post the results once I get everything set up. I plan on spending a good amount of time modeling, tweaking, and measuring the room response. This is my first dedicated room and I'm very curious to see how well very different speakers can be integrated with the room when the significant other isn't a factor.

Thank you to all of you for your comments. I definitely feel better about giving the Goldi's a try now.
Distortion, I am very interested is the outcome of your Soliloquy experiment. I have an 11 X 21 room that is divided by columns that forces me to use the 11' wall for placement. I have the Soliloquy 5.0's, but have been debating on upgrading to the 5.3 or 6.2. Keep us posted!
Try the speakers first. I had a pair of Paradigm Studio 100s Version II in a 10 by 16 room. Sounded GREAT. The back of the speakers were about 8 inches from the wall. Seating position (back of chair)was about 2 feet from the opposite wall. Carpet over floor made of wood. Walls were typical plasterboard over 2x4s. Various stuff hanging on the walls.
Try them first.... At normal level, no problems. Cranked up, the treble would drive you out!! I had no problem with driver integration.
I have heard my PMC FB1s in a very small room and they sounded wonderful. These speakers are only 6" 2-ways but they are transmission loaded and rated to go well below 30hz. You will never know til you try them.