Ribbon midrange pros and cons

bsmg

Infinity had the EMIT tweeter and EMIM mid back in the day; both ribbon diaphragm design. Innovative at the time but not a big hit.

Some of those speaker systems have withstood the test of time, such as the RS-1 and IRS Beta systems. But they aren't ribbons - they are planar drivers.

my mistake then; mea culpa

Wikipedia describes the Infinity emit and emim units as "quasi ribbon" units so it would seem I was quasi correct. 

Don't confuse tweeters like Infinity, Amt, ect ect for true ribbon tweeters like on Magneplanars, Apogees ect ect 
True ribbons are the closest you will get to ESL's, and ESL's are the closest you will get to Plasma. (it's all about mass "diaphragm" weight)

Cheers George

RAAL makes ribbon tweeters  
  
Companies like GoldenEar use AMT tweeters, they look similar but are different tech.  
  
The RAAL tweeters are some of the best on the market, but they don’t make any midranges, and I don’t think I have ever seen a ribbon midrange, probably because those frequencies require much more air movement.