'Holographic Sound Stage?'

someone thought holographic sounded like a neat word to use

truly...

Soundstage height is one of the holy grails.

A well recorded performance using more than one microphone will have spatial queues in the recording in the form of phase delay between the channels, which when played back through stereo speakers will replicate to some degree those same spatial queues allowing your mind to assign direction, distance, even altitude. Well made speakers, with very inert cabinets, will tend to better throw these sonic "images" akin to stereoscopic pictures.

Part of the ability to throw a stable image is close tolerance on the frequency responses of the left and right speaker, and smooth response with no peaks. The rest is how accurately the speakers can render those spatial queues in a way that bring realism to the experience.

Very good speakers, with the right recordings, can throw an image that extends well beyond the location of the speakers themselves, producing an enveloping sensation, a very 3D experience.

that is why I went back in time...all my stereo is from late 50's early 60ties....Have fun!

I've been at this hobby seriously for 45 years, and owned hundreds of components, and I had not heard a system that produced what I would call holographic imaging until a couple of years ago. By holographic I mean images that are completely divorced from the speakers, spread left-right and front-rear as live, in front of and behind the speakers. Frankly I had believed that reports of this phenomenon were marketing hype.
A few years ago I met a fellow 'phile through a local group that owned a system built around Shindo electronics and cables and Devore Gibbon Super 8 speakers. His listening/ living room seems unexceptional, with some treatment, but the sound was truly holographic, as I've described. Vocalists seemed to be 3-4 feet in front of the speakers, with instruments spread out, some seeming to be as much as 10 feet behind them, with a similar left-right spread, well outside of the speakers. I was shocked and stunned. I had never heard the like. I would have thought that it would take a high end multi-channel system to created this illusion, but I'd never actually heard anything like this. I've since heard this system a number of times. A couple of years ago he changed to Daedalus Athena speakers, which improved the sound greatly overall, and maintained or enhanced the illusion.
I've pondered this system for several years, trying to understand what is responsible for this and how I could reproduce it. The room has some peculiar properties, I think (although I don't understand what they are), and the owner has gone to great lengths to get his speaker positioning right, down to 1/4", using laser measuring and a positioning scheme he has embraced. I've not heard other electronics there, but the Shindo gear is at least partly responsible.
So- it is possible to achieve this, but I believe equipment alone won't do it. The room dimensions, treatments and positioning are major contributors; a major rabbit hole, should you choose to go down it.