Response 2 made a couple of pretty good points, but I'll amplify a little bit:
* Try some different positions with respect to the back wall - experiment by moving it closer and further away, you'll be able to hear what position you prefer
* Remember that side walls contribute just as much to loose bass performance as the back wall, so try to be a couple of feet into the room on each side
* I generally start with a more or less equilateral triangle with the speakers and listening position, but by all means experiment. Trust your ears.
* For a much more complete treatment of speaker placement, you might take a look at http://www.gcaudio.com/resources/howtos/speakerplacement.html
I hope this helps and hope you enjoy your new gear!
Perseus
