Where should the vocal image be?

Some one made the comment about room acoustics.  In my observations, room acoustic improvements make changes in the plane you apply them on.

To improve depth, focus on diffusion behind the speaker and listener. Width, absorption and diffusion to the sides. Height?  Floor and ceiling.

I think most images are based on the recording. But I personally prefer a center image a little behind and between the speakers.

ozzy

As already pointed out, many factors affect this: recording, system, room, positioning, etc.  There is no single "right" or "wrong" answer as to where the soundstage should begin and end.  Many people, I among them, appreciate layering, which is enhanced with a deep soundstage, wherever the front plane of that soundstage may start.  Very broadly speaking, the more you pull your speakers out from the wall behind them, the more likely you are to achieve front-back depth of soundstage.

With the Spatials I own the center image is always behind the speakers. How far behind depends on the recording. Some tracks it's a couple feet behind, other tracks it's way back there. IMO this is why OB is great for smaller rooms and nearfield listening, as it creates more distance between listener and center image. Not necessarily an intimate presentation, however, if that's what one prefers.

When I play Roger Waters' Amused to Death album the barking dog at the beginning is to my right or 9 feet in front of the speakers and the old man speaking is to my left about 7-8 feet in front of the speakers.  That is just freaky.  I prefer the musicians in front of me where I can keep an eye on them.  Most of the time the images are between  just in front of the speakers to beyond the back wall (if I have the lights out) and can extend past the speakers left and right.  For me, the soundstage grows bigger with the lights out.