You certainly do not have the biggest of rooms but you are still quite a measurement from having the smallest of rooms.
My room is roughly 12.5 ft. x 18 ft. x 8 ft. I am quite satisfied with the room demensions. Although I don't think I need any speakers larger than my Aerial 10T's.
Perhaps if you were more specific about what you think are sonic deficiencies. Take a digital picture and post it with your system.
You might describe the room: i.e.
o Carpeting, rugs, carpet pads.
o Sub-flooring, concrete, wood, crawlspace underneath, etc.
o What's on the walls? Lots of glass, windows, window covering types, etc..
o Ceiling, flat, beams,
o Bookcases, books,
o Wall panelings?
o Lamps, Floor lamps, recessed lighting, etc.
o Furishings, glass tabletops, wrought iron, leathers, cloth, etc..
o Fireplace surrounds, doors, openings, etc..
Listing these things and the placement of your speakers and listening chair can help determine what, if any, deficiencies you may be experiencing.
Then again, it could be the equipment itself as ultimately it is the synergy of the whole and the quality of each that determine the final music presentation.