Morning all!
Thanks for all the response; some answers and clarifications below:
Thanks!
When we are going to see mmcx in other models?
Can't speak to future releases right now! Stay tuned (sorry).
dayyamm!
I know right?
Is there a vent opening on this thing? Is it well sound isolated?
No vent - one of the cosmetic/mechanical changes from CL1 - the air contained within the sound chamber is enough to work with the driver's surface area. The sound isolation is

in my own experience; comes with 7 different ear tip styles/sizes/materials; 11 pairs overall; to assist with that.
2.5 balanced plug...means I can no longer use my DACAMP L1's mini 4-pin balanced output...
Not without an adapter - sorry. When we started developing the Dacamp, then the CL1 alongside it, the standard amongst balanced connections was still a contested issue. However, when time came to make a decision on CL2's connections, 2.5mm was generally considered to have come out on top.
On the subject - though the CL2 does sound great through an amplifier, it has an impedance of 15Ω (compared to the CL1's 150Ω (piezo drivers are v. hungry)), so can be driven without.
I thought I read something about the term "planar" being used for dynamic(not really dynamic, but planar-dynamic?) drivers. I guess if we think about it, you can call the driver planar as long as it is configure a certain way. That doesn't necessarily mean it's really like the full-sized planar headphone driver. The scale changes things.
Agreed. The principle of establishing a magnetic plane, and using it to move the planar coil - in this case kind of helix-shaped - as a whole, rather than the single ring, is the method we settled on.
I ask RHA to demonstrate or show us the internals in why they are calling their drivers planar.
I'll try to dig out and upload a diagram but in the meantime this that you've posted:

Here, CEE TEE is explaining how the driver functions.
Looks pretty close: concentric, opposing magnet array at the back that creates the magnetic plane above (this is one of the hardest parts to get right; set them a micrometre out and the field - and the sound - is way out); a helix-shaped coil balancing atop that field; diaphragm at the front.
More interestingly for me is to know if the mmcx bluetooth cable will be sold separately?
No immediate plans, but if it makes sense for us to make separately - or modify and make separately - never say never...
Cheers,
Colum