Why not horns?

The very best horn designs run at about 3% THD when played loud and this will distortion is audible and in treble.

Conventional non-horn designs can play loud at 0.3% THD and often much lower in the treble - pretty much inaudible.

You are talking at least a factor of 10 more distortion in a compression horn design...

The principle advantage of horns is that they are more efficient and play louder with less power. This efficieny comes at a price which is compression in the horn throat and a higher level of distortion at louder levels.

At modest levels horns can be very competitive in terms of sound quality/distortion.

I absolutely loathe horns!

Horns are great...on cars!!!

Honk, honk!

Seriously though, some are pretty good if the system is voiced and implemented well. That said, most aren't plug and play as your room interaction is can be greater.

Shadorne,

I have yet seen or heard any speaker which can play loud with such low 0.3% THD. You might be able to get a measurement In the lab playing a single sine wave signal at a particular frequency at a particular level, but I don't know of any speaker which can achieve such low THD over a wider frequency range with dynamic signal. If you know of any, curious mind would love to know.