Speaker distance

Quad ESL 57.
6’6" apart from panel centers.
Toed in so centers point at ears.
(36" inside from front wall.
47" outside from front wall.)
>36" from side walls.
7’2" to ears from speaker centers.
18" custom stands. Center of speaker panels level with ears.

Magnepan 1.7i's-7' apart, 40" from back wall, 72" from each side wall, 12' from listening position, tweeter on outside, slight toe in.
MMG's as side surround (for multi channel music and movies)-24" from side walls, 10' from listening position. 
9 foot ceilings , no "commercial" room treatments

Speakers on ends of long hallway 37 feet apart with listening  position on a Viennese Hassock between them in what basically is a tunnel covered with animal trophy heads with hissing gaslights and locked shoji doors. Great for those shoe gaze parties featuring people claiming to be your cousins.

Heh-heh

unreceievdeogma-  I have been playing with placement with my Altec Valencia 846's. I tried a basic 40/40/20.... speakers pulled out 40% of room length, listener 40% from speaker, with 20% remaining length behind listener. This didn't work at all for the Altec's, which I believe shine with plenty of distance between listener and speaker. That 40/40/20 had me way too close in my 23 + foot long room. I tried the Verity formula noted earlier in this thread, and liked the result from the room width divided by 3.6, which situated my speakers 41" from the side walls. That was using my 148" width of course. Now I'm going to play with the rest of that formula which uses the ceiling height to determine how far speakers are pulled out from rear wall. In my case my 8 ft ceiling dictates they be pulled out 4.96 ft from rear wall. Currently in my (23+ ft) room, I'm not too far removed from the suggested 4.96... Should be interesting, but so far very positive going to the 41" from side wall....I had them 44" from side wall before I began playing with the Verity formula. Thanks for posting that. I always enjoyed the Parsifal, and never noticed the Verity formula. Perhaps it wasn't available way back then.