IMAGING: width/height/depth (my experiences)
1. setup must be correct (tweeter to seated ear height) & (toe-in for equal tweeter volume dispersion relative to the mids) & toe-in to protect the primary sounds from the reflections of floor/ceiling/side walls:
result is primarily horizontal imaging. phantom off center locations created by the speaker’s L/R relative volumes.
2. Then my mind creates a ’natural/normal sense of height, imagined height of players relative to speaker created horizontal phantom location.
seated ear height as the vertical center, everybody on the same floor height: i.e. Drummer imagined lower than bass player, piano height centered, bass player tallest. Horns higher than the Piano …..
OR, often, imagining relative to a typical stage height from decent orchestra seats: height of piano centered ’above’, all else relative to that ’starting/imagined’ height
3. Depth is created by a combination of mind and open space behind the speakers:
enhanced/limited by the actual amount of space behind the speaker to the rear reflected surface. The depth you perceive is based on your actual live listening experiences, i.e. you ‘know’ the depth of a small stage for a Jazz Trio; you ‘know’ the depth of stage for an orchestra (combined with standard placement of violins left; bass right; horns centered/behind; big drums and big horns rear row.