I have not compared. FWIW ATC midrange was designed by Woodman to compete with the best panel midrange sound quality (which panels excel at) yet play loud and dynamically like the best horns (without the "honkiness" or throat non-linear distortion).
I heard the 989 a while ago and it sounded very clean but it definitely lacks SPL and dynamics, and the 989 measurements on Stereophile are concerning but who knows perhaps they messed up when the did it. Very surprising to see so much resonance on the decay waterfall plot - the panel membrane seems to be vibrating in certain modes which should be audible?
I heard the 989 a while ago and it sounded very clean but it definitely lacks SPL and dynamics, and the 989 measurements on Stereophile are concerning but who knows perhaps they messed up when the did it. Very surprising to see so much resonance on the decay waterfall plot - the panel membrane seems to be vibrating in certain modes which should be audible?