The best tweeter is no tweeter


In a recent review in Stereophile for the Elac Carina over an AMT based speaker (I’m a fan of AMTs by the way) the author, Herb Reichert, makes this statement:

My personal experience suggests that the overall sound of any loudspeaker is greatly determined by the designer’s choice of tweeter.


and then he goes on to list some speakers with AMTs, some of which I like, some of which I hate, which he feels share the same qualities. And it got me thinking about something as I hook up my home theater again. In my mind, the very best tweeters are completely invisible and transparent. I do not suggest you should use a single-driver, full ranger with a whizzer, heavens no. That’s just wrong (grin) and a clear cry for help.


What I am suggesting is that in the very best tweeters in the world, of which some are AMTs, and many are not, you simply cannot tell what they are.


That is, they are absolutely transparent. You do not perceive sound emanating from them at all. Music is just there, in front of you. Some of these are ring radiators that are really reasonably priced. Some are German or Spanish AMTs, some are diamond or Be tweeters.


In fact, my home theater has both ring radiators and AMTs in them, both of which may be found among the most prestigious brands of speakers. Though they have entirely different operating principles and materials, their performance is absolutely seamless. I barely use EQ except for the sub and center due to the latter’s location on a shelf. What both of these tweeters share is incredibly smooth output (unlike crappy AMTs or Be tweets) that is flat to beyond 20 kHz.


Please, buy what you like, but to me, if you want to talk about a world class driver, it’s not one you can sit in front of and say "aha! I know this is an Aluminum/Be/Diamond/AMT tweeter!!"


If you can tell the type of tweeter you are listening to, I can assure you it is not among the best in the world.
erik_squires
I have the Burmeister sound system in my little Porsche....It has AMT's for the tweeters (probably to save space).....not so impressed.
Most AMT will not have a good low frequency response compared to the typical dome tweeter, which means you have to cross them with a rather steep slope - most likely a 4th order slope.  Having a high order slope in itself will have its own sound signature
The plasma tweeters I have heard put the AMTs to shame. As andy points out certain tweeters require a very steep crossover which dictates aspects of the speaker's design which may or may not be to your liking. Not a fan of high order crossovers as a whole. So the tweeter itself means nothing without looking at the speaker as a whole. 
https://www.lii-audio.com/

On YT there are a number of clips with pretty impressive demo's of these drivers and speakers.
I have Maggie's and AMT done by Monitor Audio latest series. They sound hifi nice but don't sound real! I haven't heard Cube Audio single driver but doubt they can to treble better than ESL! Enjoy😃