Advantages of beryllium?


Can someone please explain the advantages of beryllium drivers over titanium or aluminum?

Also, how concerning are health risks associated with beryllium?

many thanks for your input. 
defiantboomerang
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In a publishing universe of almost completely subjective waffle without facts I like JA's measurements and graphs. I have learned to read his prose very carefully, and ignore the commercial talk. The amplifier measurements with a simulated real load are particularly revealing, I find.
Fortunately there are a few other international publications with fact based reviews.
@Koost_amojan

You are correct. The cost of the speaker is no reflection on the quality - especially the tweeter.

The Excel Millenium Sonotex soft done tweeter has the best waterfall I have seen. It is expensive at around 200 euros per unit and therefore very few manufacturers use it.

Since most speakers are fairly good in frequency response the waterfall plot plot is far and above the most important speaker measurement. Another key plot is the dispersion horizontally.

Unfortunately not many folks understand the importance.

@bar81

+1 Exactly how I read JA last paragraph. Full of euphemistic BS whenever the POS SOTA ultra expensive audio jewellry measured performance is poor in certain aspects. He is also careful not to compare products and be overly enthusiastic when performance in a reasonable price product is exceptional - usually just saying he is impressed. After all a reviewing magazine needs advertising revenue and cooperation from the industry - so it can't pick winners and it's job is to cheer on every latest product. So kudos that JA still manages to convey his views to those who are discerning enough to translate that last paragraph.
I'm sorry, did we want to talk about the price of speakers, or their sound quality? I'm confused.

As I've written, JA loves speakers that sound like hearing aids. If that's what you like, feel free.

https://speakermakersjourney.blogspot.com/2016/05/stereophile-reviews-data-doesnt-lie.html

Best,

E