I expect the material in the middle to be an electret providing the bias field.
My thought exactly, looks like they are using a transformer for a CCFL tube in design, and using the DSP chip to preshape ( distort the waveform to almost look right after all is said and done) the drive to the class D chip scale amplifiers, and have a pretty steep high pass filter in tweeter side DSP to get the crossover to be less objectionable. Regular drivers probably have an incredible amount of bass boost, and the wings probably help as well to allow the audio wave to spread a bit before being cancelled, as they will look like a solid at low frequencies.
Do not think they get 30W of audio power, might be 30W of power use at full level output, mostly used by the "big" drivers, but the wings are probably only getting 2W each. Case material for the sides and the main body probably also is somewhat conductive, heavily loaded with carbon black, to reduce static charges being induced into the covers by the foil mesh, but high enough not to absorb too much power.
Going to be a very expensive stainless steel mesh, as you have to have a precision punch and careful alignment to punch out the units, though they probably also use a premoulded hot glue edging to keep loose ends in control. Life of those cutters is not long, the stainless steel wears them, and as they will probably only cut each wire in the same spot they need regular dressing to keep the edge. Just a regular PVC cutting die in about that size is around $3k, and uses precision pins and slide bearings as well to make an assembly that is the punch, then you put it in a press. Having a tab cut out makes it even more expensive, as the cutter and the backing blocks have to be even thicker not to distort. You also have to harden them to Rockwell 65C, then finish grind them. That job Robrenz has a lot of experience doing, and I doubt his experience is cheap, even if he gives it freely here.