[Agnostic]

Some years ago I bought a Micro Seiki MX-1 with energizer. The problem with those is that the material that was originally used for the diaphragms deteriorates. As a result it is impossible to find a pair that still works unless the diaphragms have been replaced. The pair that I bought had a new pair of diaphragms but they were not mounted correctly so I finished the job and got them to work. The problem with them is that because of incorrect mounting of the membrane on one of the mounting rings, which has insufficient tension, one of the two sides has a bit less volume and sounds a little less dynamic. Despite that fact they are still a pleasure to listen to. They sound fast, have non of the sibilance issues I have with my Stax Lambda and have some of the deepest and tightest bass I have ever heard from a headphone and generally sound very musical. Because they sound so good I have always had the idea in the back of my head that one day I would try to find a second pair and do a proper job of repairing them. A few days ago someone offered me another MX-1 for free.

Now for the questions: I have no idea what the thickness of the membranes on my first set is and I would like to try to get as close to that as possible. I know that the Lambda has 2 micron membranes and that it sounds a little harsh in the treble as well as suffering from sibilance so I am guessing I should go up to at least 3 micron, though on the other hand the micro Seiki has much smaller diaphragms which may also affect the sound. Any thoughts on this?

And question number two, does anyone know where to get thin Hostaphan-RE or Mylar-C in Europe? I have found 6 micron and possibly some 4 micron but nothing thinner.