Advantages of beryllium?

Per the web site, it is Al/Mg.

Nothing against Al/Mg but Focal has this fetish for micro motors which are never as smooth or dynamic as the large motor variants.

Though lately ScanSpeak has produced some tweets which are close to the same motor size and very very good sounding.

@erik_squires 

What do you mean by micro motors? I don't understand that term, sorry.

I worry that people will accidentally stick their fingers into the tweeters of those precious Magicos…and according to at least one guy who sells them it seems that's not such rare a thing. My fragile aluminum-magnesium tweeters are covered by a mesh screen so have another drink cousin Shirley! Just don't knock the damn speakers over.

Micro-motor tweeters are just tweeters with the bare minimum motors to work. Focal as well as B&W are proponents of this approach. The motor is no wider than the dome and usually less than half an inch thick.

Despite assertions otherwise, popular micro-motors measure terribly across distortion, frequency and lack of linearity, regardless of material used.

They are routinely outclassed by relatively inexpensive models from popular driver vendors.

Best,

E