Looking at that picture in Soundstage the speakers are too close to the back wall or window as it may be. That's a very reflective surface to have a speaker in front of.
This seems to be equivalent to moving the speakers farther out into the room. This is usually enhanced with a diffuser panel between the speakers on the front wall.
This seems to be equivalent to moving the speakers farther out into the room. This is usually enhanced with a diffuser panel between the speakers on the front wall.