When I discovered full-range I disavowed multiple drivers, crossovers.
Try it sometime. It's like headphones without the headphones. Crossovers + multiple drivers kill phase information and you throw the "sound stage" out the window.
Full-range speakers have many problems, that's why we use multiple drivers in the first place.
Well designed speakers don't destroy the phase either, and even if they did, which they don't, there's also active crossovers that can do all kinds of fancy stuff.
Nothing's perfect, but multi-way speakers are a much better solution than expecting a single speaker go from 30-20000Hz.
You keep stating this phase destruction like it is gospel. However, if a crossover is negatively affecting the phasing, something is wrong. Maybe it's a cheap design on a cheap product, or a poorly made something with a good design, but if you have a crossover doing this, then replace the crossover.
Many many sound systems do not have this issue that you seem to be convinced is normal operation of a crossover. If this was a normal thing and accepted by everyone everywhere, then loud music would never sound right. I'd suggest stop buying equipment from Radio Shack ;-)
It appears it is possible to create a crossover that preserves phase but it is difficult. Most designs instead try to minimize the phase difference. (And the worse crossovers don't bother at all.)
Regardless, as soon as I listened to full range drivers (with no mid-range, crossovers, etc.) it was clear nothing I had listened to before could compare.
> It appears it is possible to create a crossover that preserves phase but it is difficult. Most designs instead try to minimize the phase difference.
This is correct, I'm not convinced being slightly out of phase is a big issue though, and wildly out of phase shouldn't happen in a good design. Full range drivers have other issues, there is no way you can construct a chassis that is equally good at reproducing bass and treble as a n-way system, and its usually the treble that suffers. This is why commercial coax systems often are layered two-way systems, eg the KEF LSX50. I'm not saying what you are experiencing isn't real, but if there weren't pros and cons then high-end Hifi (as opposed to PA) speakers would have moved to that concept, which they haven't.
Maybe what you are experiencing is due to better dispersion. You can improve that in n-way systems by adding strong chamfers to the enclosure, see popular DIY projects Disco-M [0] or LYC [1] or DXT-MON[2] (phase chart at crossover included in comment).
Try it sometime. It's like headphones without the headphones. Crossovers + multiple drivers kill phase information and you throw the "sound stage" out the window.