Could glass displace (your fave) tweeter material?

I'm not sure how many are aware that the price of beryllium has gone up significantly due to it's demand in aerospace/military.  

Alternatives going forward will become more interesting as prices continue to go up. 

While beryllium is dangerous and causes berylliouosis of the lung and other diseases,it's fine as long as you don't touch it or brake it. It is light weight and produces fast transients as momentum is mass x velocity. It pushes cone breakup out to > 20k hz beyond human hearing range so the distortion is not heard. This is why high end speaker manufactures use it. Textreme and like materials have been developed and thier modules is just behind beryllium. The new final speakers are made of such and yamaha de eloped thier own used in the ns5000 as I have the 1000 of the 80s that have beryllium mid and tweet.ps audio made thier mid and tweet ribbon out of textreme like material and it sou ds fantastic in my fr30.enjoy the music.

I was just thinking about the Yammies. One of the very rare uses of Be for a midrange.  

I’d be very curious to hear any experiments with glass mids.  

As mentioned, the Be tweeters have very high resonances, but so does glass and some other metal tweeters.  

The technology looks fine and dandy, but I bet my ears won’t like it.

We like our NS 5000's with ALL drivers made of monel coated zylon so much we will travel to Japan and buy NS-3000 and airlift them home in our luggage. Wife grew up in Japan and says it will be fun. We'll hit some great restaurants and drink delicious IPA. 

High end seduces with exotic tweeters not close to the material of their cone drivers hoping nobody askes about tonal uniformity across drivers. Planars are nice but they cannot match cones in bass.