I am indecisive about choice due to room size

Duke, millercarbon, and erik have some valid points. Square rooms are bad particularly for bass, directional speakers are the best way of avoiding room interaction and a large percentage of the way a system sounds is due to the room. 
So how do we integrate all these factors. Will going to VIII's solve anything? Not really. With more bass it might even make the situation worse. This is a room for small Maggies, ESLs and some absorption on the front wall behind the speakers. Horns would also work like Klipsch Heresys or Cornwalls.  Down the line you could add four small subs like Duke's system. I really like Sonus Faber but dynamic speakers like that need more room to breath. Right now you are being assaulted by early reflections from all sides. 

Jchiappinelli77

Square rooms should be avoided. You will have a hard time overcoming the limitations and acoustic issues of a square room by upgrading any of your components. If the spare room is your only option, I would seek help fro GIK before doing anything.

J.Chip

Mijostyn

Duke, millercarbon, and erik have some valid points. Square rooms are bad particularly for bass, directional speakers are the best way of avoiding room interaction and a large percentage of the way a system sounds is due to the room.
So how do we integrate all these factors. Will going to VIII's solve anything? Not really. With more bass it might even make the situation worse. This is a room for small Maggies, ESLs and some absorption on the front wall behind the speakers. Horns would also work like Klipsch Heresys or Cornwalls. Down the line you could add four small subs like Duke's system. I really like Sonus Faber but dynamic speakers like that need more room to breath. Right now you are being assaulted by early reflections from all sides.

millercarbon

You can toss all the above bad advice. Some of it is outright plain wrong. Adding bass for example is exactly what you need. Your biggest problem is not size but being square, 12x12. But 192.168.0.1 routerlogin 192.168.10.1  would be bigger but at least as bad. Simplistic thinking combines with poor understanding. People hear the obvious boomy bass in a room like yours and assume too much bass so solve it with small speakers. Wrong.

I wouldn't go with any of the stuff you like but I wouldn't hesitate a moment to get better speakers simply because they're "too big for the room".  

Regardless of speaker you're going to want to control the lumpy bass identical dimensions causes, and early reflections. In that order.  

Lumpy bass is best solved with more bass, not less. Using multiple subs will allow you to put them in different locations to excite different room modes and ultimately achieve much smoother bass. Duke himself, owner and speaker designer at Audiokinesis, says the benefits of multiple subs are even greater in small rooms than large.

Just one of the ways people misunderstand the realities of the situation you're asking about.

Will the speakers fit in the room? Will you be able to place them with drivers at least 3 feet from walls and ceiling? Then they are not too big.

Hi all,
Thank you very much to everyone who posted. I had an idea of what issues I should pay attention to. I will write the results here again.
Best regards.

don’t under estimate your NAIM. Look at speakers that don’t require the 3’ into the room rule of thumb. Duke mentioned some, others are Larson and Vandersteen Treo, there are of course many horns that do this. Not my cup of tea, but I get it. Don’t overtreat the room. The diagonal experiment  Duke suggests is FREE, try the gig  tommorow 

better bass is not usually more bass...

have fun, enjoy the journey and the. music

don’t under estimate your NAIM

better bass is not usually more bass...

very sound advice from tomic ... both points!

I am the king of small rooms, I have had many set-ups in small rooms that sounded great. In fact I had a 12X12 room not long ago. A small room has it’s limits on volume because the room gets saturated and the sound is bouncing all around. But listening in the near field can be very interesting and enjoyable. My only concern about larger speakers in a small room is if the tweeter and midrange drivers get too far apart you my have an issue with seating height and finding the vertical sweet spot. Other than that bigger/better speakers always sound better than smaller/lesser speakers (most of the time with some exceptions).