My room is smaller than yours (approx. 10' X 15' with it opening to the rest of my place on one of the shorter wall sides with windows on the other shorter wall) and I have my system along the long wall.
Obviously, it's not as deeply layered as I'd like it to be but the layers are there with great and stable imaging. Nothing diffuse, with quite sharp definition unless it's an orchestra.
LIke you, I have no sidewall reflections to speak of since the first, dominant signals reach me quickly due to the nearfield setup. As for the soundstage itself, it's can be wider than the speakers and the height is stable from edge to edge. The only room correction I have is my lounge and a carpeted floor, along with that opening one to side and a small computer desk and CD cabinet.
The sweetspot is small (about 3') but it's wonderful. I can't say why you don't have sharper imaging but keep experimenting :-)
All the best,
Nonoise
Obviously, it's not as deeply layered as I'd like it to be but the layers are there with great and stable imaging. Nothing diffuse, with quite sharp definition unless it's an orchestra.
LIke you, I have no sidewall reflections to speak of since the first, dominant signals reach me quickly due to the nearfield setup. As for the soundstage itself, it's can be wider than the speakers and the height is stable from edge to edge. The only room correction I have is my lounge and a carpeted floor, along with that opening one to side and a small computer desk and CD cabinet.
The sweetspot is small (about 3') but it's wonderful. I can't say why you don't have sharper imaging but keep experimenting :-)
All the best,
Nonoise