beryllium vs diamond

That is odd kosst. I did not think I offered an explanation of break up. I only mention some factors that might or might not contribute to it. You obviously like Science cop do not understand it either or how to or how not to apply crossovers or how to chose drivers to accomplish a specific goal based on their static specs. I suggest you and science cop get yourselves a bunch of drivers, capacitors, chokes, test equipment and soldering irons so you can start having fun playing around. If you are stuck for money I can loan you mine:)  

Mijy,
Waiting for some pictures...
And since you admitted you have “test equipment״ should be no problem showing test results (although according to you tests continued signals are worthless, so what exactly are you testing?)

Until then, you are added to the “ignore these wannabes” list.

Getting a bit back on track. Anyone notice differences between diamond tweeters such as those on tidal speakers and those on b and w 800 series ?

Sound better, or sound more accurate? The latter is whatever is lightest and stiffest, i.e. diamonds.  I have beryllium.  It is fine. I listen to good music, not to equipment.