aren't Accuton chassis made of ceramic?
The Accuton concave domes are made of the following materials:
Ceramic - for bass-midrange, midrange and tweeter drivers
Diamond - for midrange and tweeter drivers
Ceramic Sandwich - for larger bass drivers and passive radiators
Aluminum - for passive radiators
I believe the chassis (baskets) are cast from aluminum or an aluminum-magnesium alloy.
All of the speakers I have seen with Accuton midranges and tweeters have used the ceramic models. I would doubt any of us could afford the diamond tweeters. Madisound primarily sells the ceramic and sandwich drivers, but they do list one 3/4" diamond tweeter for $2900.
Steve