Vinylphile, You forget to mention the price of DMD in Taiwan. For such a price anyone would try I think. However by production of any driver there are deviations of, say,
3dB at least. Next to presellection of individual drivers
for a given speaker there is also the 'tuning' of the crossover to adjust the (mutual) irregualarites. Those facts are obviously overlooked by those who propose the
simple exchange of (whatever) drivers. Diamonds may be irresistable for the ladies but why should they be for the guys? Anyway I would never exchange my so called 'beryllium' tweeter for any diamond in my BE-20. One should think how difficult it is to produce good speakers not to mention exceptional kind. Every single part
is not only measured but also listened to. Even the wiring get the needed atention. And there come some amateur , looks to the wire inside and Heureka: 'cheap wire!'. And such an ameteur thinks to improve the design by putting some expensive wire (or capacitor) instead. If this 'art' of speaker production was so simple there would be no bad speakers but only exceptional kinds.
Regards,