Large Speakers Small Rooms

The simple answer is about what Newbee said. It's really more practical, in most applications, to use smaller speakers and maybe a well placed sub(Preferably EQ'd!).
Big speakers with deeper bass extension will tend to make it harder for you to get anything but bass heavy, thick, slow, boomy, "one-notey" bass, basically not smooth, flat and natrual. Small room already are heavily challenged acoustically, especially in the bass region! Putting large speakrs in there makes things tha tmuch more boomy, "unatural", "one-notey", and just plain "small room" "boom box sounding!".
Your only hope with even modest sized speakers in that room,complicated by the fact you're going to have to be near the back wall(depending on setup, but no much room either way) seat-wise, and your speaker are forced out in the room to try to smooth and even out your bass for natural sound and dynamic range.
One alternative here to making large speakers work in large rooms (like what is even comon with the small room setups at CES and other Hifi shows), is to use a good Parametric EQ on the speakers! Your basic choices are limited to either a good high end expensive parametric like Rives audio makes (see Stereophile, and or do research, even on this site), or use a basic Parametric on the bass drivers and bi-amp! This is an option on some speakers that sound good bi-amped (some don't!). IF you can EQ the bass on a speaker while leaving the other fundamentals (mid/trebble) intact, you can get some potentially stelar results with good set up and acoustical considerations in small rooms indeed! It's just a lot harder than it is for large rooms!
Still, for most, I'd recommend against large speakers in small rooms, unless you know what you're doing...most don't

If you can find a near mint pair of the old Snell Type A's you may do well with these. They are large full range designed to be placed against the wall. I've listened to them in a small room and they sounded good. I would do some room treatments regardless of the size speakers you use. In your small room cost will be low.

Dave

Avoid large speakers with rear or side firing woofers in a small room. In addition, look for a speaker that has adjustments (switches) to contour the sound. Pay special attention to the radiation pattern. You may have to use a parametric eq to get them to work.

That said- I am using Snell XA-90's to great effect in my basement listening room. 10 wide, 7 high, 22 deep.

I once had a pair of b+w matrix 802 that also worked well.

I have a small listening room - 11X12X8. My previous speakers were B&W Matrix 803s on 7" stands. I now us smaller 2-way speakers - Taylor Ref monitors on 24" stands. No sub. The overall sound quality and ease of listening has improved. The bass is tighter. Overall greater resolution and imaging. You don't need to move alot of air in a small room. Consider smaller speakers with front ports. Also, smaller speakers are cheaper than bigger speakers - quality being equal. Joel

My Coincident Super Eclipses with their two 8" side-firing woofers (mirror imaged) per cabinet sound better in my current small room (12.5 x 17) than in their former room that was twice the sq footage.

I was pleasantly surprised by how well the Supers integrated with my smaller room. I have heard from some Coincident users that the even-bigger Total Eclipses sound even better in smaller rooms. Go figure.

I recently ran a pair of Wharfedale EVO-10 monitors for about a month in my small room. The small monitors had no advantages over the much larger Coincident 'Supers'--including imaging. And the bass; you just can't approximate real, tuneful, impactful bass. Of course, if you have "bass gone wild" in your room, you are better off just rolling it off (or taming it) with EQ or room treatments. In no way, do the Coincident Super Eclipses go wild with bass in my room---using the Cardas speaker placement formula. And damn if I don't get audible presence down to the upper 20's Hz range.

Not every truism about large speakers in small rooms bares up to experience.