Hopefully others will chime in. What amp are you using?
I think dspringham is running a Sony HAP-Z1ES player and Vaughn Carina amp, so the front end shouldn't be a problem, that is, if player, amp, and speakers are hooked up direct, and the sub isn't daisy chained between amp and speakers. Also, if the system is connected somehow to a home theater setup or Apple TV, etc. that could be a problem. dspringham can correct me if I'm wrong on any of this.
I've run the SAM in two situations:
1) In an acoustically live 13' x 25' x 8'h room on the short wall with a venetian blinded window right behind. Amp and DAC were Audioengine N22 and D1 DAC. The sound was rich and full.
2) In a slightly less acoustically live 13' x 17' x 8'h room on the long wall with Audio Sector DAC and Decware Super Zen Select in front. To this day, I've never heard a better system. Full and rich with insane imaging along with the most balanced frequency curve with no one area overshadowing the other, allowing incredible detail retrieval.
As far as his room goes, it's generally not a good idea to put a system in front of a window (I also realize this may be his only option). The adjacent wall might be better. Also, RDavidson could be right in that the listening position may be in a bass null. I had the same problem in my 13' x 17' listening room with a system on the short wall and my chair about half way down the room - somewhat lacking in bass. No such problem on the long wall.