The music is made with that in mind when in the studio... The "phantom center" places the vocalist in the middle. Yes, you can also master music to have a center channel which could be a mono vocalist track.
Most music doesn't seem to be a traditional "music event." The piece was never performed as you hear it. Even if it was, you're still reliant on the engineer creating it with omni speakers in mind, or stereo speakers. Most of the time this is directional stereo speakers and you're compromising further going with omnis.
Seems like you might like something like the BACCH SP that can help you get a cleaner stereo image that doesn't seem as blurred.
www.theoretica.us
I know perfectly well how a phantom center is created, as I have mixed my music formany years.
Just because our hearing is tricked by the stereo illusion to hear the phantom center as if it is a real sound source placed in a central position between the stereo speakers, the actual sound still originates from the physical positions of the two speakers in the stereo setup.
But when it comes to the room reflections, that phantom will no longer be treated as a single sound source point by the room, on the contrary, it will be generated by the actual two physical positions of the two loudspeakers.
So back to your initial idea...
You were talking about a dry recording of a single vocalist, and the spatial sound was supposed to be generated by the room reflections of the listening room, right?
If those reflections will sound completely natural as if they were generated from a single source (the vocalist ), a single mono speaker must be used, not two because they will generate room reflections from two sources.
Do you see the problem now?