Hard Audio - Ceramic Speakers

Are the Accuton ceramic midrange drivers pure ceramic or are they sandwich type?

I found this paper regarding Harman's CMMD drivers that were used in the Infinity line for quite a while:  https://www.excelia-hifi.cz/infinity/data/ceramic-metal-matrix-diaphragms.pdf

The new DCC cones in the Revel Be speakers reportedly take the CMMD design and improve upon it.  

I think the original Accuton were pure ceramic but they used dampening rubber dots to tame the materials tendency resonance. In recent years the dots have disappeared so perhaps damping is on the inside of the cone where you can’t see it?

Accuton are very good drivers.

Harman’s CMMD look very good on paper. The fact folks are still working on this problem shows you how pesky it is!

ATC solution to breakup (bending) of softer materials was to use a dome shape supported by a large 3 inch voice coil. They also had to use a massive 20 LB drive motor to get the necessary SPL out of such a small dome. Finally a 3 inch voice coil in a 3 inch dome is going to suffer from rocking motion - so ATC use a double spider to maintain alignment. So ATC solution works brilliantly to overcome the highly damped softer cone material issues however it comes at a huge cost - a very expensive transducer.

These newer designs that concentrate on fancy cone material structure look promising to be more cost effective but can they be mass produced with consistent quality? Will they last? And do they work better and as reliably as the “brute force” ATC massive drive motor style approach to dealing with softer damped materials - Time will tell.

Whatever the solution - internally damped drivers are absolutely critical to SOTA speakers.

Maybe I'm just fussy, but as far as I can tell, those Infinity drivers are basically anodized aluminum drivers. That is, they make aluminum drivers and then using acid and current (I think) they transform the outer layers. This is essentially what Calphalon does for it's cookware, no? 

And yes, Accuton are considered technically among the best drivers made. Certainly based on measurements and low distortion this seems to be the case. And yet... I'm happier with paper cones from Scanspeak. Kind of why I started this thread. :) The engineer and music listener in me do not reconcile well when it comes to these particular drivers.

Best,

E

Give me some kind of paper woofer and a silk dome tweeter any day.