From "
Describing Loudspeaker Sound."
"Forward" indicates that vocals, male and female, tend to be very present, almost as if the singer were standing in front of the plain of the speakers. It can be a negative term, too--if singers sound too close up it may mean the midrange is boosted or exaggerated. The opposite is "recessed," which means that midrange sounds like singers and choruses seem to be farther back, a bit distant-sounding and well behind the plain of the speakers.
I don't know if the M40, M50 owners would describe them as "forward" but they have the reputation of NOT being as forward as the M2/M22/M60/M80 line, due to a slight bump in the lower portion of the frequency response curve. Regardless, you will not find Any Axiom speaker "muddy," or "muffled and, being very accurate speakers, they will expose a poorly mixed or mastered CD.
If your ratio of movies to music is correct, I'd definitely recommend the QS4s for surrounds. They are fabulous surround speakers for movies, and no slouches when it comes to music.
I agree with Bray, the M22s would be real good in a room that size, but that doesn't mean the M40s or M50s would be bad, either. With the M22s being bookshelf speakers, when considering the cost, you should add in the price of stands.
I also agree that, regardless of your choice, being a movie watcher, a sub is a necessity.
