How far apart do you position your speakers ?

For those with the non symmetrical shaped rooms or just as an experiment you might want to try using the Master Set speaker placement. There's a review of it here on Agon
http://forum.audiogon.com/cgi-bin frr.pl?rspkr&1197744079&read&3&4&
Or just search the web there's plenty of information on it.

My set up is in a alcove that's 13.5' wide X 5' deep but opens up to a room 28.5" wide. The right side is 20' from the listening position with the left side opening to a stair case that ascends to the upper level. I tried the Cardas method several time and could never figure out the math for it.

After reading about the Master Set I gave it a shot one rainy weekend and after two days of working with it by myself was surprised with how well it works. And trust me you will get tired of the song you use, haven't listened to "The Balled of a Runaway Horse" in months.

I'm not saying it will work for you but its just a option.

Good Luck

I started with finding the best seating position in my room. I did this by ear, listening for the best balance for a smooth and articulate bass response. Then I placed my speakers front to back for staging/depth while maintaining good bass balance , then distance from the sidewalls, listening to female vocals in mono for solidity and focus of the central image, and finally toe-in for a final check on tonal balance and detail. They ended up about 85% apart relative to my ear-to-tweeter distance and toed in to meat at a point about 4-5 feet behind my ears.

When this was complete, I then checked speaker height/rake angle and toe-in angle with a laser pointer aimed at marks on the back wall. Finally, I checked the distances from the tweeters to side walls and tweeters to a center point on the back with the laser measuring device. Everything is to the nearest 1/16th of an inch. Sounds pretty anal, but this last step with the laser pointer snapped imaging and focus in place and the speakers disappeared to a much better extent than before.

This procedure is basically described in Jim Smith's book, "Get Better Sound." I had tried various test tracks, listening tones, etc, but always became frustrated with a lack of progress. I did the set up listening to real music and following Jim's advice. I found it worked best for me.

Depends on room and how far away you sit.

Doesn't the nearly infinite disparity between various speaker's responses in rooms, including tweeter off and on axis dispersion and woofer loading sort of obviate set-up formulae? And...has anybody CHANGED the speaker position months after thinking one has dialed it in due to some personal tonal preference change of heart? And is "formulae" really a word? As an aside...yesterday I draped a blanket (tastefully of course) over the back of the leather couch I listen from (providing some high freq. absorption on either side of my head), and it dramatically cleaned things up.

Hi Wolf, To answer the question:
"Doesn't the nearly infinite disparity between various speaker's responses in rooms, including tweeter off and on axis dispersion and woofer loading sort of obviate set-up formulae?"
I don't thinks so. At least as far as how your speaker loads or couples to your room. The idea is to be far enough from walls to avoid reflection and be close enough for proper bass reinforcement. Then to be in the right seating position to get the most from your soundstage.
I don't think that Whether you are 83%, 95% or triangle is any more important than understanding standing wave, reflections and reinforcement, this is where some type of formula could come into play. On or off axis listening is a factor of what your final frequency curve is in the room. As, I'm sure that you know, as you take your speakers off axis, you change the top end response heading down to your mid range. If your room caused some sort of peak, much of this could be alieviated when you go off axis, or if you have a very flat response, most of us would like to listen on axis.
Either way, the boundries, could be summed up mathmatically.