Well I got a specialist to place my speakers in the room for most even frequency response 25 years ago. I am not much bothered by stereo image type stuff
I would die for a great virtual 3D soundstage. And i am not saying a natural soundstage but even when it is a result of processing.
In particular i like when i read in some articles about the feeling to be transported in the concert hall or a church where the even has been recorded.
And when this soundstage extends beyond the room walls. Imho there is only one way ... to cancel wall reflections.
I think we hear an object when it reflects the sound. Bats use this principle to avoid obstacles i understand.
And what a torture must be to put bats in anechoic chamber ... they would crash on the walls. Or in a reverberation one they would get crazy.
Some strategically placed acoustic panels should help. But it is complex.
Once the reflections are tamed i would eq the response curve. But from what i read low linearity is more acceptable than high distortion.
Another idea is to switch to speakers with limited dispersion like horns or similar. Very small sweet spot but i have to find a compromise.
I saw this extremely interesting SW
https://www.ikmultimedia.com/products/arc3/?pkey=arc-system-3
it seems very effective. I am thinking seriously to buy it. Only problem i am now far from home ... and now i live in a hole.
but instrumental timbre is very important to me.
i think this should have to deal with low distortion ? of course this is a fundamental aspect for realism. No question about that.
25 years ago the only way to get a (fairly) even in room frequency response was the actual position of the speaker.
Nowadays it is easy and cheap to use room correction for that but IME you get a better result if you carefully position speakers first,
since the hollows in the response are shallower (and they aren't corrected by most correction systems due to power requirements) and the peaks are much smaller so the corrected sound isn't appalling elsewhere in the room. Best to minimise excitation of room modes first and correct second
Thanks again clearly i have to study more. But
reflections are a pain. I knew about that at a friend home. He had a perfectly sqared room.
I remember he playing a cd and stopping the track after a bass note ... the sound was going on forever Like ten seconds and more !!!
That day i understood what room reflections were.