The last two posts were both very good and packed full of info that I agree with. It seems to me that very few people realize how critical specific tonality (represented by a detailed freq response curve) is to soundstage characteristics. It's absolutely primary and critical, and acoustics (timing at listening position), clarity, and dynamics are also factors, but don't matter without the right freq response.
3-Dimensional Soundstage
I have appreciated a quite nice separation of instruments in my system's soundstage. I have read many times about people experiencing depth in their music and have never appreciated this. I was talking to an audiophile friend this week about it and he brought up the fact that recorded music is a mix of tracks and how could there be any natural depth in this? If there was a live recording then yes, it is understandable, but from all studio music that is engineered and mixed, where would we get depth? Are the engineers incorporating delays to create depth?