Video request to Paul - ribbon tweeter vs air motion transformer

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@Rudolf_Appel

Chris did write that AMTs are folded.

If you read my question more carefully, the question is asking about ribbon… If you have the answer would appreciate if you can help. Again, for 3rd time (emphasis on bold):

5. AMT diaphragm is folded but ribbon is not , is that correct? Therefore is it correct to write that AMT diaphragm can be described as squeezing air but ribbon cannot ?

@Rudolf_Appel

If you like Oscar Heil speakers, another person who worked with Oscar Heil is Herr, Karl Heinz Sonder, he founded Abacus in Nordenham Germany. His son Hanno has studied physics (including acoustics and electronics) and is also extremely knowledgeable.

Abacus dedicated the 2 top of the line speakers Oscara 212 and 210 to Oscar Heil, hence the speakers names.

Abacus Oscara

These would have been my preferred speakers by far. To my opinion absolutely superior technology, I love the sound of their AMT driver speakers and active technology. Their products are really made in Germany, all enclosures, all PCBs and electronics except of the components (that are only manufactured in Asia), even most drivers, the ones they use are all European.

Very interesting

@Rudolf_Appel

So we look and listen to many different options. I cannot dispute that there are better looking speakers out there. There are many options in that price range.

Indeed. This thread is not seeking answers on which is better or best. Moreso just understanding differences. Once again, see my earlier example of marketing that causes confusion.

I’ll share it once again for you reference

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Another example of why this is confusing and this time it’s not the marketing department but it’s one of the best speaker designers on the planet.

First AJ refers to this tweeter as “folded ribbon”… and then a couple minutes later refers to it as “AMT”…

Based on this and who he is I’m starting to think they are much the same unless @Chris_Brunhaver can help

ELAC's Andrew Jones Explains His New Carina Speaker – Audio Advisor

[Chris_Brunhaver]

5. Yes, an AMT dipagragm is folded and these pleates move laterally, squeezed together like a bellows.

When you say ribbon, there are actually two things that you might be referring to:

1. A pure foil ribbon
2. A planar magnetic (which Igor/BG calls planar ribbon or infinity calls EMIT/EMIM). These are like a flex circuit have a polymer backing and and conductive traces.

These move axially, like a traditional dome tweeter but diaphragm is directly driven axially by the magnet system.

6. Yes, while there are different embodiments, some AMT magnet systems use neo bar magnets to the sides of the diaphragm (not front and back), like the parts express ones (and the same vendor makes the goldenear ones as well), which may have similar construction. Without showing simulations, basically center conductors aren’t getting quite as even a flux distribution in these types of design.

The HEDD ones that Rudolph shows have a bit different motor design with an outer steel tube and pot, so it depends on the implementation somewhat.

121.26US $ 6% OFF|high power ribbon tweeter planar transducer AMT diy audio...

For a planar (of the symmetric/double sided type), there are magnets in front and behind the diaphragm and so the field and structure very symmetric. Here is a cross section showing the magnets and traces.
http://www.integracoustics.com/MUG/MUG/articles/planar/pp.jpg

As I think that Rudolph was alluding to, the implementation matters as much as the core technology. However, I was just trying to give you some background on the various “thin film” driver types, as I do think that there is a bit of a shared “sound” among them, differences, not withstanding.

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Thanks for drilling down further Chris.

I agree that these thin film diaphragm share a common sound from my subjective impressions.