Single driver vs traditional 3 way loudspeakers

I prefer keep it simple with as few drivers as possible, usually 2, but 3 can be good too. One is OK but will always have limits. Reality aside, 1 is best  ideally at least.  
Bottom line is coherence is what holds my attention listening.  Various ways to achieve that. 

Well not exactly a single driver, my Canterbury’s sports a dual concentric 15” surround with a embedded 2” aluminum/magnesium alloy dome.

Frequency response is pretty impressive as well...28 Hz - 27 kHz (-6 dB) with a crossover frequency of 1.1 kHz.

In my opinion a good "fullrange" driver can do many things well, but the frequency extremes are generally not among them.  I'd be inclined to keep bass frequencies out of it and use a dedicated woofer, and to add a tweeter to improve the top-end dispersion (and extension if needed).   

There's a speaker company in New York that does this.  I think their name is Bache Audio, or something like that. 

;^) 

My first commercial effort fifteen years ago was almost that (6" Fostex + powered bass section + tweeter), but I made the fatal mistake of not high-pass-filtering the "fullrange" driver.   Might give it another go some day.  

The best single-driver, truly fullrange speakers I've heard are the big SoundLab electrostats. 

Duke  
disclaimer: I'm a SoundLab dealer

Of course, this is a great subject to recommend DIY experimentation.  Madisound, among others, has a number of affordable full-range (single driver) kits you can play with while you are stuck at home with the kids. :)

I prefer a single full range driver to multiple drivers. I have a pair of Charney Audio horns and love what they do. Over the years I’ve had multiple driver towers, 2-way bookshelf’s, open baffle, etc... None have ever come close to the intimacy of a single driver horn. Charney Concerto and Lumaca with the 8” Voxativ and AER drivers will do exceptional full range sound.