Describe the sound of point source loudspeakers?

@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.

The Tannoy Dual Concentric speaker system is stunning - period !.
From near field listening at whisper quiet levels to room filling in row g of a auditorium.

• The point source sound from the Tannoy DC design is used in recording studios and residential locations because it retains the accuracy of the spoken word regardless of listening distance. This is so important because most listening environments are not room/speaker friendly. 
• Finally take a Tannoy DC speaker system and listen to spoken word at WHISPER quiet level - listen for the articulation & coherence of the speaker, you are now listening to the speaker minus the cabinet and it sounds so correct, so undistorted. Now replicate that same test with the mass of line array speakers - by comparison they sound broken !.
• A 15" Cobalt Dual Concentric Tannoy speaker system mounted in a 200-300 litre bass reflex cabinet will play all styles of music with ease without fatigue. The Joe D’Appolito 2 & 2.5 way speaker design have wife acceptance factor and look pretty with there narrow baffle profile which is currently so fashionable but imo sounds thin & broken compared to the Tannoy DC

Cheers Johno

       

hi there tuberist : ) - is what you meant by 'point source' loudspeakers those that do not have multiple drivers that require crossovers internally and good geometries for their drivers externally, such that the sound waves from each driver arrives to your hearing in correct phase and timing? I'm not sure if I have used the precise terminology, so do excuse me if not.

in friendship, kevin

As in a speaker with a single driver that covers the entire frequency range?