Sorry, no pictures - I'm an analog kinda guy
Here's a better description of the room. The room is 20 x 17, the system will sit on a long wall, one corner of which is cut off for a fireplace. To visualize, the fireplace is on the right side of the room. The short wall (sharing the fireplace) had a double window with relatively heavy curtains (Weaver's cloth) and shades. An antique secretary sit across the back corner. The back wall has a 5ft opening (Actually open french pocket doors, they can and probably will be closed for most listening sessions - the doorway is about 4ft from the corner, so it's affect is minimal.) Next to the door opening is the listening sofa and a 2 end tables. The opposite short wall has a chair and another french pocket door (in center of wall).
The ceiling starts at 8ft and peaks (in the center of the room) probably around 16ft. The peak runs parallel with the short walls.
Given some decorating limitations, I'm stuck with the equipment/listening positions, also the sofa is against the back wall and must stay there. Both upholstered pieces are colonial style with high overstuffed backs. The room has wall to wall carpet.
When I walk around the room, clapping my hands, I hear a lot of slap echo, more the closer I get to the center of the room. Dog barks seem to echo forever
I was wondering if placing something at the peak would reduce the build-up of pressure and hence reduce the echo.