How important is it for you to attain a holographic image?

By your logic, a person sitting in the first row of a concert and ostensibly getting a more “holographic” picture of the sound, is having a better musical experience than someone sitting in the fifth row or tenth row or balcony.

I don’t think that’s the case.

Orpheus10,
Your sliding door experience got me thinking about the glass I have over a large piece of art in my listening room. It is also hung on a side wall (much like your sliding door). First I tried a heavy handmade blanket over it. My impression was "who turned up the bass". I belive what was actually happening is it was sucking the highs & some of the midrange out of the room. Didn't like it much. So now I have it covered with light cloth. This is an improvement. Increased bass without the objectionable suck of midrange/highs. This also increased focus of the soundstage. Thank You!    

Boxer12, Often reflective side walls can be conquered by simple, but radical toe of the speakers, with out the need of using ugly treatments on the walls to deaden high frequency reflections. Often, not always. Give it a try if you already haven't. It worked for me. FWIW there are other benefits to this type of speaker set up as well.  

Boxer, leave your speakers alone, they are a very critical adjustment that I'm sure you have fiddled with enough times to have them precisely as they should be. Nothing is worse than messing up what you already have right.

Increased focus of the soundstage means you are close to having what we're after. Stop and evaluate.

I'm sure everyone has fiddled endlessly with speaker placement and toe in until they've gotten a satisfactory left, right and center channel image. This will not change when you are attempting to get "holography".

We are into "The propagation of sound" when we get into this dimension we call holography.
Geoffkait told of some of the professional devices that can be helpful; however, that goes into a whole other realm of study, and expense; I used as much common sense as I could muster along with flat out "luck", and succeeded beyond my wildest dreams.

Once holography is realized, it's like entering another dimension in sound and music; tone and timbre sound closer to the actual instruments, the music on old records sounds like new music.

I didn't change one component or move one speaker; it was all about room improvements in regard to the propagation of sound.