This is one of the reasons I like Tom Holman’s work. BTW, if you haven’t checked out @mikelavigne virtual system yet I think you’ll find it a great (perfect?) example of room setup:
Tomlinson Holman research on wide’s states:
1) The front half of the room is more important than the back half!
What is perhaps the most repeated mantra I heard during my visit was how the decision to add 2 rear channels when 7 channel sound offered itself as an improvement over 5 channels is according to Audyssey, a serious error. IF these extra channels are available, they should be added to the front, NOT the rear. Why? Human hearing has far better spatial acuity in the front of us than we do behind us. According to Tom Holman, we can resolve auditory spatial information to about 1 degree in angle in front of us from right to left, (Horizontal plane) and about 3 degrees in height (Vertical plane). Both of these sensitivities are far greater than what we have for sounds coming from behind us. Hence Audyssey’s preference of multiple channels in front and sides, and one required for rear channel sound.
2) Width is more important than height!
Width is crucially important in placing instruments and recreating acoustical space. Concert halls with side walls perpendicular to the stage are considered by experts on the subject to be acoustically superior spaces to fan shaped halls. One of the reasons here is the importance of the early reflections from the right and left side walls perpendicular to the stage. In the "fan shaped" concert halls, the splayed side walls did not support the same kind of early reflections and are one of the main reasons these halls are not judged as good by the experts. To quote Mr Holman, "it is known in concert hall acoustics that the first side wall reflection is the single most important reflection direction, it sets the auditory source width... Channels constrained to plus/minus 30 degrees are too narrow for that". For this reason, the DSX standards (7.1, 9.1 and 10.2) support a left wide and right wide channel at plus/minus 60 degrees to reproduce the kind of side wall reflection you would hear if you were seated in a great concert hall."