Mockturtle - As I said in my post just before yours, and I thought I made clear in the original; the 83% was a suggestion for a general place to start, not a rule. I completely agree with Dave's observations that no two rooms should be treated the same and there are no hard and fast rules, just generalizations. I offered the number simply as to share a suggestion of where you might start. I do not agree that that the Sumiko Master Set is the last word in placement, and in fact it may not work well in some situations. An example is if you are forced to set up speakers on the short wall of a long room, or if you are forced to listen nearfield with limited space to move back placing your listening chair up against a rear wall - Sumiko, as I understand it, suggests a minmum distance of 2 feet from the rear wall behind you, which sometimes just doesn't work (in which case you could apply some treatment to deaden the rear wall). You have to work with what you have and optimize it however you are able. Certainly, when you are able to use it effectively the Sumiko technique seems to work well - I heard their room at RMAF '07, which sucked in terms of dimensions to work with, yet rendered brilliant soundstaging and was of the handfull of memorable sounding rooms there that year. In dealing with smaller rooms my experiences have been similar to what you are describing and it has seemed more critical to get the speakers away from the side walls to get a focused soundstage. In my room my speakers sound better currently spaced further apart than 83% (i checked after I read that figure and tried moving them closer but did not like what it did to the staging). I have no sidewall on one side and am listening nearfield. I tend to loose soundstage scale by moving them together. My room is very unusual and I am at task to tame it further while trying to juggle WAF, and have been making some baby steps in that regard. I believe the room is a very important part of any system.
