" I have yet seen or heard any speaker which can play loud with such low 0.3% THD. "
"ATC claim this on their highest end designs such as the SCM300 while playing at 121 dB SPL (definitely loud). I am skeptical that they can actually achieve this down to 20 Hz but I imagine it is not far off the truth especially with a 6 db bass boost from a typical soffit mount - certainly from 40 to 20 Khz it can probably be done. Of course, at normal volume levels the distortion is probably even slightly lower but 0.3% THD is definitely approaching the limits of speaker technology even at moderate volume levels."
I find this interesting as the baffle in the "soffit mount" is what gives you the 6db of gain. This is the same property as a horn with all of its issues. Soffit mounting done properly is useful. Improperly done, and it can be just horrid no matter how great a speaker you put in there. Besides working out proper placement, the fabrication of the soffit itself is very important as it becomes a transducer along with the speaker.
