No idea what the manufacturing process was in those days, but didn't Yamaha try this in the 70's with the NS-1000? But they for sure weren't capable of taming the beryllium the same way then it is possible today.
No. As I already mentioned, Yamaha NS-1000 and NS-2000 models used vacuum-deposition proces on copper-plated aluminium molds. The NSX-10000 model, introduced in 1986, was the first (and AFAIK the only model) which used pure berillium domes:
Midrange driver used in the NSX-10000 was a dome. Paradigm have introduced what seems to be the first pure Be mid driver with
cone diaphragm - much bigger, and I assume much more difficoult to manufacture than any cone.
This is how Paradigm Persona 7" Be mid looks like:
It has quite the surrface area and I can only image how difficoult it is to manufacture. Focal once used to tell people (when they started pressing their Be inverted domes) that Be drivers are so expensive not only because of the cost of the Be itself, but also due to the fact that 90% of the pressed domes ended up in a trash bin (due to cracks and other defects). Now those numbers are supposedly lower as they managed to increase manufacturing process efficiency, but it is still not an easy material to work with.
And BTW, while speaking of the Yamaha - the NS-2000 introduced in 1982 was on of the first speakers that used carbon fibre woofer:
It was 30 years later when Magico introduced their carbon fibre based (and nanotubes reinforced) cones. As you can see, the Yamaha's CF was not even woven.
Yamaha was a true innovator of the 70s and 80s. They had huge R&D budgets, so almost everything was possible.
And btw - those speakers still sound excellent. It was the brittle sounding SS amps of the era that gave them their bad name, not the speakers.
