Advantages of beryllium?

https://www.madisoundspeakerstore.com/air-motion-transformers-amt/mundorf-amt25d6.1-r-dipole-air-mot...    https://www.madisoundspeakerstore.com/soft-dome-tweeters-morel/morel-titanium-supreme-tsct1104-tweet...  https://www.madisoundspeakerstore.com/ribbon-tweeters/raal-original-140-15d-ribbon-tweeter-with-amor...          in my own hands on experience these options sound better than BE options from SEAS ScanSpeak and Satori   

Hi @johnk

My main speakers use the Mundorf AMT's.

I wouldn't call them the best... but I would call them among the very best. :)

Implementation and room matter a great deal too, but I absolutely agree they are among a small, stratified set of tweeters that should sit at the top of the hierarchy.

Best,

Erik

I heard TAD Be drivers in the mid 1980's. No way I could sit and listen to one then.

Maybe it was the electronics (Haffler) but ouch!

Best,

E

@shadorne 
@erik_squires 
https://www.stereophile.com/images/417wilsonal.Walexfig5.jpg
https://www.stereophile.com/images/1114FA936fig8.jpg
https://www.stereophile.com/images/817Rav2fig8.jpg
https://www.stereophile.com/images/217MagS52fig7.jpg

Which of you two smack talkers is going to explain to me exactly how ugly the decay plot of a Focal 936 is? 2 of these graphs are from $40,000 speakers, one is from a $109,000 speaker, and one is from a $4000 speaker. Help me, because I'm confused. I'm not exactly seeing the superiority in the silk dome and paper at least in terms of measurements. Looks to me like that Al-Mg micro-motor inverted dome is holding it's own a bit better than the silk and Be. In fact, it looks like you can blow WAY more money on speakers and get much less impressive measurements. Shadorne is up there whining about 5 small 1.5ms decays. That $109,000 Wilson is pretty much averaging 1.5ms decays all the way up to those TWO nasty spikes around 15kHz. 
So Erik, I did the homework you couldn't/wouldn't do. I just randomly picked some of the best reviewed speakers in the $40,000-$110,000 range and looked at their measurements. As far as I can tell, you're pretty much wrong. 
Though not exactly a meticulous examination of all the available tweeter designs out there, It appears that Be is a decent material capable of exemplary performance, Al-Mg holds it's own decently well, and silk absolutely blows. I mean, if ANYBODY is going to get silk right, wouldn't it be Wilson?

Wow, that Alexx waterfall plot is a disaster. It’s too bad you didn’t link to the actual measurements page where in the last (useless) paragraph where JA (if he needs to completely ignores the measurements and) blows sunshine up the manufacturer’s butt, even he has to grudgingly note how bad the waterfall plot is.