Is there measurement that correlates with cohesive/pinpoint imaging?

Within a frame work of two channel audio, it is not simply timing information that is important, but relative timing information, i.e. the time difference between arrival at both your ears. To that end, a large baffle will not impact the primary wave front timing differential between a signal from one speaker to both your ears. Maybe you meant something else?

Time and Phase. Study how the highly evolved ear brain function to localize food and threat sounds and you will understand it is small timing differences. Add in low diffraction because a large baffle destroys time information while functioning as a mechanical averaging machine ( frequency response )

There are predictors of great imaging. The first is avoidance of cross overs and phase aberrations. The second is that both sides have identical frequency  response curves. This one is tough, No two speakers are exactly alike but then you put them in different positions in the room. Maybe there is a window on one side only or whatever. The point is that each speaker has a unique acoustic environment. This is why symmetry is so important.
The best results are always going to be with a "one way" and full spectrum room control. With the best units you measure each speaker with a calibrated microphone then correct the speakers response so that they are dead flat. Then you can make adjustments as you like. The best unit out there now is the Trinnov. Anthem and DEQX make decent units.
Many "audiophiles" downplay the use of these devices feeling that they are just like tone controls and equalizers, detrimental to the sound. They are not. They are digital and process at very high speeds, at high bit depths. There is no distortion, phase or otherwise.

Perfect frequency response from both sides sounds like it would be super important but in practicality for what most people describe as imaging it is not. Symmetrical installation in general is far more important.


What most people describe as imaging is not exact placement, which has no meaning at all really. If I have a left / right volume difference and something shifts 6" to the left or right, that is not going to be critical.


What most describe as imaging is an ability to visualize an exact spot for the sound source, not just "over there" though a lot of people like "over there". A well designed cross-over is going to provide, given suitable speaker/listener distance time coincident wavefront and certainly with digital cross-overs, it is very easy.

Certainly you are familiar with the two slit experiment, just model a mid and a tweeter on a large baffle and let it rip for a few cycles.

as for precision matching of drivers and pairs, that is a hallmark of Vandersteen for 20 plus some years now, I know they all go in the chamber for a filter tweak as well - the 7 are matched to .1 db as I recall
- the matched pair are delivered with the actual plots. Obviously an unsymmetrical room can present challenges, as Eric suggests some treatments might be appropriate and of course there are fans of DSP.
Of course this fanboy has other speakers that have positives as well: Quad ESL 63, Thiel 2.3+, Dynaco A-25, some Totems.... some tiny baffle Sonus Faber that throw a super big 2D image ....

rather than focus on hyper flat frequency response maybe measure the RT-60 of your room.....

measure and listen but always enjoy

Whenever a question arises, regarding sound stage and imaging; I make this suggestion: The following provide tests, with which one may determine whether their system actually images, or reproduces a sound stage, as recorded.      ie: The LEDR test tells what to expect, if your system performs well, before each segment.      On the Chesky sampler/test CD; David explains in detail, his position on the stage and distance from the mics, as he strikes a tambourine(Depth Test).      The Chesky CD contains a number of tests, in addition to the LEDR.    (https://www.audiocheck.net/audiotests_ledr.php )      and: (https://www.discogs.com/sell/release/2818064?ev=rb)      An article, in Stereophile, on the subject: (https://www.stereophile.com/features/772/index.html)      The LEDR eliminates the variables, far as what's on your source material (recording/miking methods, etc), when doing listening tests, in your room.