Dayton Wrights had "cells" enclosing the membranes and containing sulfur hexafluoride (SF6) gas. There is no mention of ozone being produced in the documentation, since the gas filled enclosures were not intended to leak (a Schrader valve on the bottom of each speaker, similar to one found on a car or bicycle, was present for adding SF6 if ever needed). The most frequent cause of failure (leaks) were cats, mentioned in the manual. Cats like to jump to high places, and the punctures of the enclosures were a certain distance off the floor where the cat(s) dug their claws in. The XG10s I have work perfectly, never a leak in their history, I was told by the previous, original owner.
Back on topic, the Acapella tweeter produces ozone which is dissipated in the throat of the horn before it escapes to the room. I don't know about other manufacturers, but ozone production is a very significant problem to be dealt with (ask Nelson Pass or Alan Hill).
Back on topic, the Acapella tweeter produces ozone which is dissipated in the throat of the horn before it escapes to the room. I don't know about other manufacturers, but ozone production is a very significant problem to be dealt with (ask Nelson Pass or Alan Hill).