beryllium vs diamond

Sciencecop, I hate to say this but you have no idea what you are talking about and you are having trouble applying the manufacturer's  data to real life performance. Those frequency response graphs you are referring to are take under static conditions. Music is not. It is dynamic. Whether or not a cone "breaks up" depends not only on the frequency but on the volume and duration of the signal.  I know from experience that I can apply certain drivers that way in that format with insanely good results for a point source speaker. 

Oh and Sciencecop, I can digitally emulate any crossover you can think of and on the fly bi and tri amping. Making analog copies is child's play. 

@mijostyn
Like I said, you are a geniuses, rewriting the book on loudspeaker design. Please share the bliss with us and show us your speakers, and of course measurements of your “child's play” results. I am sure you know how a phase cohere step response looks like, right?