I'm looking to learn about Air Motion Transformer technology

A lot depends on the quality of the AMT ,in the Wharfe Dale 
maybe $50 each  top AMT can go over $400 each the bigger ones 
operate from the midrange to high frequency , I have had Dayton $70 AMT that were ok but lacked refinement, I have a Monitor audio Studio , which took a lot of technologies from its $25k flagship and its very refined and reasonably priced under $2k 
since I rebuild the Xover even in speakers over $14k many times it is the weak link using cheap Xover parts  just to save money .
80%  of speakers under $10k use what I consider at best average grade a Xover parts. Since it is the heart of your Loudspeakers 
everything goes through there are greatly determines the detail and refinement you get. I had the owner of Harbeth hang up on me 
when I questioned him on a $4k speakers using $3 Taiwan capacitors, being in the U.K. another $100 and using local Clarity capacitors would gain much more realism that is just one example 
even the $80k Martin logan using under $10 capacitors , I called them on it ,when spending good money like that you should get the top Of the line brand they choose to use. Makes no sense to me have some pride ,to me I would rather pay a little more for higher quality ,or just upgrade the Xover  .

Spatial is using them in the new X3/X5:
http://www.spatialaudio.us/pagex3

Heil speakers used the AMT ribbon tweeters in their speakers back in the early seventies, if I’m remembering correctly. Those were the first AMT tweeters I’d ever heard of. They were ESS made I believe. You can still find them for sale on Ebay. They were German made (hence the Heil name of the inventor) so I seriously doubt they had any cheap Chinese plastics in them.

Mike

jbhiller,

In full disclosure, we manufacture our own AMT drivers and AMT based loudspeakers here in the USA. We have lots of experience with ribbon technology as well.

As you may already know the ingenious AMT drivers were invented by the late Dr. Oskar Heil.

As with most things in audio there are many solutions to most design challenges. In many cases the implementation of a technology is more influential on sound quality than which technology is used. Yes, different driver designs have different characteristics but how they are used in the overall loudspeaker design is what's important.

The AMT design is fairly versatile but is almost exclusively used for tweeters. Generally speaking, I would say that a well engineered AMT can be just as detailed and resolving as the best ribbon drivers and would describe them as "lively" or "high energy". This is one of the reasons some speaker manufacturers find it difficult to integrate them into their loudspeaker design.

We designed our AMTs to be extended range drivers. In our Apollo line the AMT array covers from 120Hz to 24KHz. IMHO, AMTs can be excellent M/T drivers. As low mid-range and upper-bass drivers they are even more excellent but they have to be designed and built for the task.

IMHO, I wouldn't get caught up in what they are made from or whether the substrate is Mylar, Kapton or cardboard. Go experience a pair. Only you know if they are right for you. 

Mike

@tomic601

I just meant that relatively we overspend. Is a $2K tweeter with a $300 mid-woofer really a good balance?

P.S. - I am guilty of this myself. :)