I got some 0.9 micron mylar last week and finally had time tonight to make some diaphragms out of it. What a profound improvement! Trebles are much more pronounced, although there may be a very slight reduction in bass. I also notice the soundstage moving more forward away from the center of my head, which is awesome. Certain female vocals sound as much as a foot in front of me.
I very much still prefer 2um dust/sweat shields than 1um. I think they provide just enough damping to suit my taste.
Although the price to pay is that the material is a nightmare to work with. Procedures that work on 2um mylar (which comparatively is as strong as brick) will likely not work on 0.9um. I had to add tape where each tensioning clip goes in order to balance the load to prevent it from immediately sheering the whole sheet of mylar as seen in the following photo. With 2um mylar, I can just clip directly to the film.
I wonder if there are sources of even thinner mylar. I've worked with 0.1um films and they are certainly too fragile for electrostatic headphones, but I imagine something in the range of 0.5 - 0.7um could be made to work with sufficiently well constructed tensioning jigs.
Edited by dude_500 - 5/11/13 at 11:28pm