I'm too lazy to read the whole thread, but what about doing it like this:
first, do the front wall for well balanced sound, using mirrors to indicate where and how much absorbers/diffusers you will have to install. In my room, i treated the whole front wall.
second, you should need to have much stronger absorption/diffusion on the right side, where your windows are, to compensate for the relative lack of reflections on the left side. for this you use mirrors again, and you install a wider surface of treatment than needed.
third, use bookshelves or whatever to diffuse reflections from the back and backside.

in all of this, the main listening position should be well considered; too far back and the acoustics will be too reverberant,
and too far forward will diminish the reverberant sound field and give you too much direct sound.
one must choose the best compromise in placement.

i tend to like better hearing the original acoustic ambiance than too much room reflections which tend to subdue the natural ambiance and sound more artificial.
if a room does not have enough absorbers/diffusers, high level sounds will be overbearing and distorted and it will be impossible to listen to music (and movies) at reference level.
i have realized in the long run that any music or movie that is not listened to at reference level will seem distorted compared to the right (live) level where the sound will be wholly natural and much more detailed than at any other volume, even by .5 dB more or less.

when one is near the optimum sound level, small changes are heard as changes in tonality of the instruments, while large changes sound like adjustments in volume.

Last edited by J. B.; 09/24/14 04:14 PM.