erik's got it sussed, and geoff's got the clues....HRTF is why headphones work so well, and the 'ambient' (whether real or 'created') is what we experience with any given pair of speakers to a greater or lesser degree. And then we devolve into where and how our speakers are placed in a given space, what the space consists of (what's in it, what's not, how that's arranged, hard/soft surfaces/materials, ceiling height, width/depth, toe-in/toe-out (sounds like Arthur Murray to me, two, three, four...), what you've drunk or not, etc., ad infin...
You either go bonkers with creating the 'perfect' space, which will Still be a relative rationalization unless you're an audio engineer with a talent for spatial calcs of a mind-breaking sort and a better than modest budget OR you can 'ignore the room' (per Linkwitz) which is where I'm at (it's a leased space that I can't go nutz in, and I'm cheap) OR you can do the best you can with whatcha' got with the furniture that's there and the SAF.
In the nutshell most of us occupy, that's the devil's deal. My omni's complicate the issue, given what they do in a given space. So I play with active eq, a tad of delay, and strike a deal with the space which is Very 'Live' (everything is 'hard' and unforgiving...).
It works well enough. Been in worse, been in better....
