In my experience I started with by-amping Adcom 555s . It sounded amazing but only a 6 foot circle in the center of the room between the speakers . When I upgraded to the mc452 that was a whole different story. Soundstage grew exponentially. My room is of similar size 15/20 with speakers set up along the 15 foot wall 7ft. apart. The soundstage grew from 6ft. circle to the whole back of the 15ft wall. My opinion is for a better soundstage is amp, amp ,amp.
What affects front to back depth in room/ system?
I've been moving speakers around for a while now trying to maximize their placement for a happy balance of soundstage width, focus of center image, vocal height, instrument placements, etc. I want to get the speaker placement settled before acoustically treating the room. The room is 15x20 with 8' ceilings. Speakers are setup along the 20' wall. I'm pretty happy with most aspects of the sound, but what I can't seem to figure out is how to improve the depth. Honestly, I'm not sure if what I'm after is attainable to begin with. Is it possible to have depth that reaches the listening position in a 2.2 channel sound system? The depth behind the speakers is great, just not much in front of them- unless it's one of those songs that has a part where it has that inverted phase trick. Then it washes over me. I want that all the time. Any feedback and advice is appreciated.