I've been following along, merely for informational purposes.
Originally Posted by coctostan
It uses 2 diaphragms in a sort of push-pull and doesn't seem to require a crossover.
I defer to you in all things CD, but push-pull
isn't correct as I understand it..and I may be wrong.
I believe it's more to the tune of a co-entrant, dual driver scenario. Not unlike a mini dual opposed IB manifold, whereby the energy pushes in phase towards each other then is routed out the exit. I immediately think of it this way ... because I also describe/think of my quad, dual opposed IB manifold as not unlike a compression driver system when someone inquires.
But the D2, the twin, it's said the anular drives lower moving mass, yet maintain overall radiating area as their typical CD approach. Thus, increased power handling, etc, and supposedly better HF characteristics (smoothness, extension, distortion, blah blah). It would be interesting to determine the genesis of the JBL team pursuing this approach.
I'll stop, and continue following along, it's been interesting for sure.
Best of luck to all involved.