Acoustics experts - a little help please

@thom_oz  exactly what I am trying to improve on. 

Not sure if your read the whole comment... @thom_oz 

The definition of 3D is getting a li’l blurred here. I have a couple of combinations of purist stereo, especially one built around a pair of tads that will do what you’re trying to describe and more.

Multichannel ’Object based’ 3D audio is a technology that only came around 2014 onwards for residential use and it is a different thing. It has nothing to do with channel based stereo or older/legacy ’channel based’ multichannel audio. The current proved-in upmixers for object based audio are 360 reality (Sony), Auromatic (Auro 3D), Neural X (DTS), DSU (Dolby) and a couple that are proprietary to Yamaha.

With the latter, it doesn’t matter what the quality of your recording was. A setup for object based would comprise of a minimum of 5 to 7 bedlayer speakers and 4 to 6 height/ceiling level speakers. This technology will pick up some trash stereo mix and discretize it, put it up as a sonic dome all around you, stretching from the perimeter of bedlayer+ceiling speakers and beyond. Sound engineers can also produce a object based audio mix for such formats, in which case you won’t need to upmix anything (considered a native mix),

When set up correctly, it didn’t matter that you had 9 or 11 speakers, all of them will disappear and you should feel like you’re floating around in a sonic dome/sphere. Sound objects will materialize and disappear, materialize/disappear, materialize/disappear anywhere in space inside this sonic dome....like ’flowers’ blooming and going away.....it’s called 3D.

"Hey, i got my almost 100 year old technology called stereo, but, now i have a muscle speaker and it is all 3D now"...doesn’t quite work like that. Some purist stereo streamer/dac manufacturers have some dsp "enhancements"/ soundstage tricks hidden away through FPGA, etc...didn’t matter, phase is off, etc and it is still limited by 2 speakers sitting up on the front stage.    

Why is this 3D not all that  prevalent? a simplifed answer is that it costs a lot, needs a huge room, steep learning curve, probably requires hiring a professional, etc...

@deep_333  why would you say:

"Setting expectations straight, 3D is a foolish concept concept in purist stereo." -?

I’m primarily listening to CD thru McIntosh MX-113 and a 2200 amplifier, and Sonus Faber Cremona speakers. My experience with this is 180 degrees opposite your assertion.

It is dependent on the recording quality (and most modern releases won’t cut it) but in my treated room listening to pop, jazz, classical and even some older electronic music I can get a massive sound stage with well-defined height, width & depth. Sometimes the center image seems to float behind the speakers and sometimes well on front of them. On many tracks a single element will sound like it’s behind the wall that’s behind my head.

The effect can be even more pronounced when listening to my (spotlessly clean) vinyl with a Rega P6 and Ortofon 2M Black cart. I blame this added sense of space to the crosstalk & delay inherent to vinyl playback, that and the extremely high quality of some vintage lacquer cuts from tape-not-digital. "Lush" barely describes the experience.

Further, any stereo mix is not set in stone. If the mastering tech got too high the night before, you got a trash mix from him the next day.

Any enthusiast can a learn a few things from the pros and by himself, get some hardware, study some pertinent software and remaster something to his tastes. 

On your ’personal’ remaster, you can "fix" a existing trash legacymix,... enhance the soundstage, put some "depth" on it if need be, drop the noise floor, fix the anemia, etc on a stereo mix...or you can level it up to a full blown object based audio (atmos, auro, etc) mix on your own...

It is my favorite pasttime, in fact. The avg audiophile could learn to remaster something instead of tweaking away with fuses and cables.

The type of speakers, or the type of drivers in your speakers, has a great deal to do with ceiling treatment.

@deep_333  you're correct that I was not thinking of object-based surround or 3D audio at all. For my uses and room I haven't pursued expanding past 5.1 in my surround-sound music, and I only own one Atmos capable music disc (Abbey Road on Blu-Ray) anyway.

A point I was implying and not outright stating though should be clarified:  a simple, clean & accurate stereo setup in a moderately treated listening room can deliver spectacular results when playing back vintage, high quality stereo recordings delivered in any format. You might be blown away at the information you have missed, buried those records that you've listened to already 300 times. And if you're hearing more on headphones than from your pricey, well regarded home speakers (rather than vice-versa) the untreated listening room or indifferent speaker placement may be the problem.