I was curious so I opened up the right ear cup (no wires ) today at work and looked closely at the material covering the HOLE on the stereomicroscope at the office. Couldn't get any photos, but the material is definitely porous, and more cloth-like than anything, but maybe not woven...more like spun material. The recent posts seem to indicate that everyone now believes this should have been obvious. True acoustic cloth is transparent to sound so this must be something slightly different as it is clearly meant to control the air flow into the driver. We really need to try some of the mods without removing this material from over the hole. I do not have Mikros#2 yet to mod, so it won' be me.
I found this self stick 2 mm foam material at W-Mart in the kid's craft aisle...medium density, closed cell I believe. I f any one wants to try it PM me and I'll send some in the post. I have 5 or 6 sheets that are about 9" x 12".
Bonus...comes in a variety of primary colors, as well as black and white.
Edited by zombywoof - 3/12/14 at 6:31pm