Speaker distance and tow in?????/


My room is big / 18x30. But due to arrangement I can only bring out my speakers 2 ft from back wall..... side walls not an issue. My 2 main L-R are 8 1/2" apart ( center to center of speakers ) . How far back should my seating be? I "think" there is some "basic" math to work from for far field seating. In my "near fields" it is all equal.... as a rule of thumb. Tow in is another adjustment. I am just looking for some "basic" good info and hope I don't start something... You guys have spent a lot of time on these issues..... and I am glad to have your suggestions!
mlbattey
Kef says sit at least as far back as the speakers are apart. Proac suggests no toe at all; you should be unable to see the sides of the cabinets from the listening position. I did that for a few years but now have mine pointed straight ahead and like both the sound & image and the look. No rules, just right.
Rockvirgo mentioned the most common rule for speaker to chair ratio. I have used this with good success. It's too bad you can't get the speakers farther out into the room. This would make a difference, at least, and probably an improvement.
Toe in is really speaker dependent. Some respond better no toe in while others sound best aimed directly at the listener. Fortunately toe in is generally easy to adjust.
Most common loudspeaker/toe-in orientation I've seen involves speakers toed-in to apex of equalateral triangle & some kind of ratio formula. See: http://www.cardas.com/content.php?area=insights&content_id=26&pagestring=Room+Setup

I've also see other room set-up recommendations. See: http://www.audiophysic.de/info/aufstellung/beispiel_e.html

I use the Real Traps method. See: http://www.realtraps.com/art_room-setup.htm

As you can see, there is no generally accepted formula.

Good luck!