+2 @kofibaffour
No way a room that size how you describe it is over damped. Maybe your listening spot is in a null?
Room treatment
My listening room sounds overly dampened, and I want to look at options for making the sound brighter. The room is 4 meters by 7 meters by 2.75 meters. Two walls are mostly covered with bookcases, and two walls are partially covered by curtained windows. The floor has wall-to-wall carpet. What should I consider?