Question

I have no information on your situation upon which to base any recommendation.

 If you care to provide the dimensions of your room, the locations of doors and windows, a description of its furnishings,  a few comments on where you would propose to place the speakers, your budget, what kind of music you will primarily be listening to, and as how/where you will be listening, I could probably give you a few thoughts.

http://www.cardas.com/speaker_placement.php

This supports newbee's suggestion. Certainly not "the rule" but effective.
Any other detail probably a speaker forum topic

   I have my Summit X's about five feet from the back wall, flanking a fireplace and about seven feet or so apart. Every room is different; experimentation as to placement is critical.