Another interested in this topic… I run Heils in my work shop & ribbons at home. One day I WILL take the Heil speakers home & actually properly audition them… one day… not today though. Today revenue has left me rather cranky…
Per the WIki article, the diff is that AMT (a.k.a. “Heil”) drivers, instead of vibrating in a pistonic or diaphragmatic manner, transfer energy to the air by “pinching” it between the folds of the accordian-shaped conductive foil. I recall that the example used by Heil when the driver was first introduced was to imagine squeezing a cherry pit between your thumb and forefinger to launch it forward instead of pushing it with the palm of your hand…
My understanding is that a “ribbon” is a smooth conductive membrane, maybe slightly corrugated or pleated to add strength, as is the case with the Magneplanar ribbon tweeters. In an AMT driver, the conductive membrane is configured as a folded structure. Apart from that, both are suspended in a magnetic field.
The ribbon moves as a planar diaphragm when a signal is applied. The AMT moves somewhat (but not exactly) like the bellows on an accordion, “pushing” the air from within the folds.
Again, just my understanding. Chris B. should weigh in…
Like the Manger bending transducer, AMT and ribbons the LMT is an weideband alternative to doe tweeters.
Manger speakers are beautiful, if I had the budget. AMT speakers sound also really good, I had the chance to listen to Abacus AMT active speakers. Sounded great.
Likewise I had the chance to compare Burmester B38 to Piega ribbons, about the same price. Listened together with my sister. It became apparent that women are much more capable of hearing heights. My sister preferred the Piega Ribbons and I the Burmester, the balance between bass and height was much better with the Brmester to me for my sister the bass was more in balance with the Piega and she found the heights just amazing, for her the best.
I love the Sonus Faber sound also and they utilise a soft dome tweeter. My Yamaha MSP 5 Monitors have metal dome tweeters and they reveal any detail.
So I find the discussion about driver types a bit academic really. It’s the complete speaker that makes the sound and different people have different preferences.