Rear wall effect on sound stage location?

Do you have anything to prevent reflections off of either wall. Some of the difference might be tamed by good room tunes.
Without having seen your arrangement it is impossible to answer accurately but the reflections off of the walls can cancel signals and alter your soundstage not to mention your frequency responce in that room.

Don't overlook your individual cabling, components, and speakers and the synergy thereof.

If your speakers are properly positioned and the room acoustics are adequate, yet your friends all have a slightly more 'forward' presentation for say female vocals and you do not, there is a possibility that one of your components is slightly recessing that part of the spectrum.

However, I'd recommend starting out by bringing your speakers about one foot further out into the room and see what that does. I believe the front center of my woofer is about 5.5ft from the back wall.

-IMO

What kind of electronics are you using? I've found amps to be the biggest factor in soundstage location. Many amps offer a first row seat, some seats on the stage, some a standing row only seat against the back wall, and others all spots in between. Other electronics also affect this, personal taste dictate what is "right" for your ears....

Thanks for all the ideas, I hadn't expected so many variables. In general, where is the most preferred location for the sound stage? Behind, even or in front?

Sean: I wanted to clarify that my speakers are on the short wall and the room is carpeted with an appolstered couch and chairs. If you clap, you get some echo. I have not treated the walls although the rear wall (behind the speakers) has windows with shutters which I keep angled down for diffusion.

Bufus: Thanks for the link. I'll check it, however, there is no way I could get the speakers that far out (there is a living room and a dining room to be considered).

Nrchy: One of the side walls has a fireplace with a marble face and I'm sure that is causing reflections. Any ideas on how to deal with that?

Stehno: I never considered the components as you suggest. I will try to squeeze another foot out for the speakers. I find if I move them an inch or so each week, my spouse is less likely to notice!

Socrates: I am currently using a ARC LS 15 with a PSE Studio IV amp (ST). I am hoping to get an ARC tube amp soon and it will be exciting to see what the differences are. What is your experience with the ARC? Forward or back?

Thanks Sean and Stehno for explaining. I heard Merlin VSM and male vocal is VERY forward compared to B&W Nautilus. There was 15 feet behind VSM and 6 feet behind Nautilus but VSM still had more forward presentation.
Must be combination of Nautilus upper mid dip and beaming while VSM has a rising midrange as described in Stereophile review.