Single driver speakers. Are they worth considering ?

One thing I forgot to mention. Specs for loudspeakers are extremely misleading. No 10 inch driver goes flat to 30 Hz in a normal room not even 10" subwoofer drivers. The measurement was taken very near field under anechoic conditions. None of these single driver systems produce any real output below 100 Hz and Ralph is quite correct. The driver flaps at 30 Hz just the same even though it can not project that frequency in a room. This doppler distorts all other frequencies. Roll off the bass at 100 Hz and the speakers will magically get cleaner. This is the same for large one way ESLs, removing the bass increases headroom and detail to unheard of levels. 
Many speakers make due with just mid bass. Our brains, tricky things that they are, extrapolate the fundamental. 40 Hz is more palpable than audible. Real bass you feel. If you do not feel anything there is no real bass. This is what makes live performances so incredible, the palpability of the music.
Big drivers beam treble which is fine as long as you sit square on with the driver at ear level. I have been living with beamy loudspeakers for decades. Ralph is right again. Whenever you see whizzer cones, run away! It does not matter how fancy the magnet looks. Whenever you see "fancy" in a driver, run away. Some of the fanciest looking drivers are the junk they sell for cars. If it looks good it must sound good? Right. 

Enjoying this thread!

Since Covid shut pretty much everything down a year ago, I needed a hobby.

(Idle hands are the devil’s workshop...)

So I’ve been building a lot of speakers. The bulk of which have been full range drivers. These run the full gamut from simple vented book shelf speakers, folded horns, pencils, voigt pipes, BIB enclosures (1/2 wave Horn) and really big double horns. 
There really is something special to my ears that comes from a big a$$ed horn speaker. Are they compromised? Sure they are, what speakers are not? The big double horns have so much “breath” in the sound, so much air . Sound is very unique, and people seem to either love em, or...  As an experiment, my friend bought an old Heathkit 8 watt EL84 based integrated. Synergy was insane. They worked so well together! Such a pleasure to listen to.

Im a fan of the single driver horn speaker. And as was mentioned by someone earlier in this thread, my hearing stops working somewhere around 13khz, so doesn’t really matter much what happens after that. Though I suspect my cat has other feelings on that subject...

Have not felt as though I was missing much in the bass. But I’m not playing organ music, or watching movies, so not really too concerned  about what happens below 40hz

For comparatively little money, and a bit of elbow grease, not that difficult to build and there are some interesting designs out there. Two drivers, some decent plywood, glue and some tools, you can experiment...

https://www.frugal-horn.com/downloads/SpawnHorn-v2-planset-181117.pdf

Yes, Dale Harder's TLS-1 and TLS-2. Single driver, no crossover. Omni directional speaker with perfect time and phase alignment. Fully coherent 360 degree sound dispersion.

Check him out at www.hhr-exoticspeakers.com

Check out my system page for a pic. 

Those are something else!

Looks like fun to build but a lot of work for a single driver system. The bass is still going to doppler distort everything else the driver does. For such a large speaker why not do a two way transmission line speaker. There are excellent passive crossover designs out there or use a digital crossover.