speaker placement help


My room is 13'x18'x11'high. I have my speakers on the short wall 6 feet into the room and about 33 and 1/2 inches into the room from the side walls. The room is rectangular and I have the speakers perfectly symetrical.My question is that should my listening position be an equilateral point from the distance of the speakers or is it OK to have my listening position 1 and 1/2 the distance of the speakers back towards the back wall therefore having my listening position at the back wall as opposed to three feet from the back wall.I've tried both ways and find I get a better bass response with the listening position at the back wall but some say it's good to have distance between your listening position and the back wall and others say it's OK to be at the back wall.Any help would be appreciated!!!
128x128mitchb
I thought the following article might help.
http://www.audiocircle.com/circles/viewtopic.php?t=4077
I can't seem to get a strong 50Hz and 40Hz but 30Hz is quite strong. All other frequencies appear equal by my ear.
In other words, how can I improve my mid bass?
Thanks for all your help.
It sounds like the best speaker configuration for me is having my head equidistant from the distance between the midline of the speaker to the midline of the other speaker. I'm actually blown away on how good this setup works for me. I'm getting the low frequencies I was missing as well as tons more detail in the mids and highs.
A question I should ask is that according to the Golden Ratio rule my speakers should be 70" from the back wall which they are and they should be 43" from the side wall which they are not. I find that 43" from the side wall to midline of each speaker puts the speakers too close together having the speakers 5.8 feet apart. I like the speakers 7.25 feet apart for the wider soundstage.At 7.25 feet apart my speakers are 34 inches from the side wall to the midline of each speaker. Any opinions or advice would be appreciated.