most accurate loudspeakers....

Perhaps, but it was mainly the fact that they can play loud and not break.

Agreed but isn't that what accurate reproduction is about? The 120 db dynamic range of our hearing! Many unamplified instruments have huge dynamic range, which means they can go very loud indeed - especially transients from percussion and from wind instruments, such as horns.

There is a plethora of good speakers that can perform extremely well up to about 100 db SPL (most with mass-produced Northern European drivers), you know, Typical Hi-Fi Speakers.

Well loud yes but at what distortion level? A car horn can produce a 120db tones anytime. That is why you do not use PA speakers in your home. There is a big difference between the need to simply amplified and the need to accurately amplified. And when I say accurate, I mean liner FR and low distortion. Two things that PA systems are not very good at.

Roypan -- the measured distortion levels produced by ATC at high spl are comparatively low (unlike many PA systems). That's actually a useful thing.

escalante femonts

Gregm- I have my doubts. The only independent measurements I have ever seen of an ATC speaker were not very impressive. On the contrary. The distortion levels of their dome midrange was completely unacceptable (Stereo Sound issue 155).
I must say, that to my ears, that is how they sound as well. Especially when driven hard. They get harsh and glossy sounding as soon as you push them.