Describe the sound of point source loudspeakers?

A point is by definition a dimensionless or infinitely small location in space. Dimensionless or infinitely small objects cannot possibly produce sound. (Some will no doubt now go chasing after these speakers with zero room interactions.) I mention this only to illustrate how easy it is to go off the rails talking tech. Jargon is a creature unto its own.

I never once in my life went to hear a point source, or a dipole, or even a horn, folded or otherwise. Never went to audition isobaric, line array, or any other speaker design approach. All I ever went to audition was speakers. Then evaluate whatever I hear in light of the room, music, associated equipment, and yes maybe even speaker design. Maybe. Sometimes.

In other words I never put the cart before the horse.

Another audiophile version (of many such tales on this forum) and as current as the original: "The Emperor’s New Clothes"

Dimensionless or infinitely small objects cannot possibly produce sound. [Emphasis added]

... "infinitely small objects cannot possibly produce sound."

Lay version:  https://www.newscientist.com/article/dn4320-big-bang-sounded-like-a-deep-hum/   

https://faculty.washington.edu/jcramer/BBSound.html

One speaker comes to mind when you say "point source", and that is Tannoy....I guess you can include KEF as well, however they are not the same design as tannoy. Tannoy was the first and is the best, since the origination of the dual concentric driver in and around I believe 1947.....it's what really put Tannoy speakers on the map....
https://www.tannoy.com/our-story.html

@tuberist, you are using the correct term ' Point Source ' as it relates to Audio / Sound Reproduction.
Specifically Coaxial / Coincident Drivers are only a variation on a theme
covering the Audio Spectrum with more than one ' limited range ' of a driver. 
KEF produces a range of different Coaxial Drivers for their products as an example of innovation from a manufacturer.
The ideal and the exercise of Loud Speaker Design is to produce a coherent ' Sound Field ' using a set ( Mains / L / R ) of Loudspeaker Systems that result in a detailed Stereo Image.
To answer the topic question directly ... the ' Sound ' would be very much like what you already have with the Von Schweikert Loudspeaker System.
In other words you would have go a long way to improve the ' effect ' that you already have with db99se IMO.
I did not want my response to sound flippant.

" A point is by definition a dimensionless or infinitely small location in space. Dimensionless or infinitely small objects cannot possibly produce sound."

Well Miller, astronomers say time and the universe started with a big bang at a point source.  Reckon we could have heard that alright.