Speaker placement formula


I tried looking in the old threads and I didn't find what I am looking for. Hopefully this isn't a subject that has been asked about too much.

I am looking for a formula (I'm almost positive Martin Logan prints one in their manual) that calculates speaker placement in the room. It takes into account ceiling height also. I know about the whole equilateral triangle, but I think Martin Logan's is different. And if I'm not mistaking, ML's is a pretty common formula? I could be wrong. If anyone could help, that would be great. Thanks.

Seth
s7horton
Oh yea and one other I forgot to give you, Its a software program you can download for free and does all the math for you, Check it out.

http://www.moonaudio.com/softwar2.htm

Also Home Theatre Setup

http://www.moonaudio.com/softwar3.htm
http://www.reflexlabs.com/page728283.htm
The cost is $50.00
There is also a company in NH who sells it for $50 plus $6.00 shipping - this was in the latest Audio Critic or Audio Xpress - can't remember