Hard Audio - Ceramic Speakers

I think the Raidho's are great. I have the D3.1's. Raidho uses a particle accelerator to fuse a diamond coating on the ceramic driver. 

@erik_squires, "every ceramic speaker I’ve heard sounded cold, clinical, pure without power."
That’s mostly how I’ve heard it, though not universally. Not only the Raidhos, but I’ve also heard what I remember may have been a Mastersound at a long ago Stereophile show in NYC that beguiled me. Lumen White products certainly come across as the poster children for what you’ve described.
Crossover topology carries so much weight, as much as the drivers. So if I designed around such drivers, and my preference would not go in that direction, I’d have that at the forefront of my mind. For me, that means series crossovers beginning with a zeta value of 1.2, and experimenting up to 1.5.
A final thought, people don’t realize the (literal) brittleness of ceramic drivers. Yes, just like any other ceramic such as a plate or cup. I’ve seen more than a few loudspeakers that feature them shatter in transport. And these drivers obviously cost a lot, so replacement is less than fun. Speakers have it hard enough at the hands of UPS and FedEX, so please keep that in mind

Hard rigid solid drivers may be pistonic but they also vibrate internally. This is a FACT.

They sound terrible to anyone with a discerning sense of timbre. They simply aren’t musical at all even if the articulation can be impressive.

Those who just listen to the impulse response may prefer these type drivers. They can use cheap drive motors because they are light and efficient. However if you try to listen behind the action you will easily hear the splashy sound these drivers tend to make and it can be extremely fatiguing. Like everything, some designs are better than others and some even approach but do not surpass the best soft domes or pulp/paper/woven fabric designs.

That said - sandwich of rigid cones with an internal viscous damping layer are much better but they quickly start weigh as much as or more than conventional drivers and therefore require big drive motors.

@trelja
They lack power because of cheap drive motors and small voice coils. Also the splashy hash created after the transient means the transient no longer stands out as it does with damped drivers.

Simple analogy - a tight bass drum head creates a booooom sound. Place a blanket inside or an Evans EQ kick drum muffler and suddenly the kick is transformed into a more transient canon shot - basically the resonance head has now become damped - it produces the initial explosive force of the batter on the head and then rapidly goes quiet and the kick drum sounds extremely dynamic and punchy. A speaker is not a musical instrument so the extra resonance from rigid drivers is a curse for critical listening even though the sound may appeal to some - it sounds a lot like jitter or poor quality digital sound and some like this splashy or etched sound.

@shadorne I think you are right about the sandwiched ceramic drivers, the new Revel Performa3Be speakers are quite low in sensitivity, officially rated at 86db. I bought one a pair of M126Be however I noticed they need noticeably more more power than other similarly low sensitivity speakers.

What do you think is better, pure ceramic or beryllium for a midrange? From what I understand, beryllium is a metal that bends, but is also isn’t internally well damped, wouldn’t it have a similarly splashy sound to a pure ceramic driver? What is the materials science reason behind both hard (ceramic) drivers and beryllium (a metal that bends) both having internal damping issues?

And what would you consider your ideal midrange driver material?