From what I have read the membranes are actually “normal” thickness somewhere between 1.5 to 2.2 microns and the graphene particles are embedded in the membrane material itself which is made of something entirely different. This cut and paste from an Audeze rep on the “other” site:
“CRBN's nano-tube infused film is between 1.5 - 2.2 microns, I can only provide a range not a specific number
Also beyond a certain point it does not make much sense to chase thinness, air-loading starts to dominate, stability and robustness become more important. We have even tried 0.5 micron thin version...“