3D imaging


I I started thinking about this yesterday. What makes speakers produce a 3D image? I figured the first thing is the recording itself. I'm guessing mic placement has a lot to do with this. Next I would imagine is room,and speaker placement. Downstream gear certainly has to have some effect on this. Does the crossover have something to do with providing this "illusion " for lack of a better term? 
     Now please understand,I don't have anywhere near the technical knowledge a lot of you folks have,so as you explain this phenomenon,please dumb it down for me! 
    Thanks in advance,
        Ray
128x128rocray
So I built my system on research by Prof. Edgar Choueiri made during his work at Princeton in his 3D Sound Lab I experienced over 20 years ago: 

The moment for me was playing on humble Sansui speakers in my home under construction listening to a recording processed through the BACCH filters, my mind was officially blown. 
BACCH 3D sound works best with very directional speakers that limit reflections. I have optimized my room from the listening position on my current system with time alignment, phase, and room interaction on 12 biquad filters operating at 96/24 on each of my 8 channels of my fully active set up. 
The image is stable and amazing on my system and it feels like being there, friends and neighbor’s jaws drop, but it actually gets better, and I’ve heard it. . . the last piece is BACCH. Take a look at the technology:
https://www.theoretica.us/bacch4mac/
Hoping to add it this Spring! 
millercarbon,do you use HFT's with traditional acoustic treatments,or are these applied alone?

Sorry for the late reply. So many threads ruined so often and so fast by the same few people I tend to say what I think needs to be said and then that's that. But anyway...

Here's a photo of my room. Its old, 2004, but its good because it shows some of what I went through. http://theanalogdept.com/c_miller.htm
The yellow panels are Owens Corning acoustic panels, the same as used inside 90% of expensive professional room treatment. There's people like Duke (Audiokinesis) you can trust to post gold. Then there's guys like me who have to work at it more. This photo is working at it. 

Just like Duke said above, its real easy to over-do it, acoustic panels predominately affect the top end, and so can really alter the rooms acoustic. So this was moving them around learning first hand just what that means. The room now has none on the walls. Only the corner tunes remain. Very effective, with hardly any downside in terms of being overly damped.

My tests were made moving whole panels around. First reflections requires only about a one foot square. It could be that if I went back and tried just a small one like that, might like it. Heck now to think of it got some in the shop might just do that. Just because it sounds great doesn't mean it can't sound even greater. 

HFT are a completely different technology, much more sophisticated, work regardless of the room, and so are used together with the same traditional acoustic panels. 

They don't have to be. Look around YouTube, there's a demo in a very ordinary room, pretty crappy room actually, way too lively, way to sparsely furnished, no acoustic treatment at all. Ted adds HFC and even on laptop YouTube you can hear the improvement. Pretty remarkable stuff. 
millercarbon,beautiful system! I understand completely about people chiming in and kind of being the poop in the punch bowl. One thing I have learned in this hobby is to not discredit something that might be different or off the beaten path. Especially for things I have no experience with. When starting out trying to achieve better sound,I truely believed there was no way a cable could make any difference. As my equipment got better,well,I'll leave it at that. Hopefully this spring I'll begin the room treatment overhaul. Like you said,just because it sounds great,doesn't mean it can't sound greater.
    The journey continues.
rocray OP
What makes speakers produce a 3D image? I figured the first thing is the recording itself. I’m guessing mic placement has a lot to do with this. Next I would imagine is room,and speaker placement.
The last one is the biggie, you should have nothing between the speakers, and as far back as you can get, this will be the best way of getting the most imagining and depth properties to be had.
Forget placing your "glitzy equipment" in between your speakers (so you can gaze at it in wonderment while listening) this is a killer for image and depth, it should all be at the side, well back
Cheers George
To my ears,I seem to be getting very pleasing(again to my ears) imaging. However,I do plan on heeding your advice in moving my equipment next to and slightly behind my seating position. I’m expecting even better imaging with that change. This will also coincide with treating my room better. Fortunately as this is a dedicated listening room,I am able to pull the speakers out well in front of my rack. This being a temporary solution until I can free up space to move my lp collection out of my small (9x13x8) room.