My DIY electrostatic headphones - Page 33

Quote:

Originally Posted by chinsettawong 

Ok, I think that we can now confirm that the sweat screen tames down the bass somewhat.  Perhaps its' time to look into what better material is suit for this purpose.  Stax uses a different material for all it's sweat screens.  The material is really thin and fragile.  It has some wrinkles on the surface.  What it is, even Spritzer doesn't know.  

It's very thin PVC film but I have no idea where to source it.  I use the slightly thicker variant found in grocery bags for dust covers or just very thin mylar with almost no tension applied.  

spritzer: any idea what they used on older earspeakers? (e.g. on SR-3?)

Quote:

Originally Posted by spritzer 

It's very thin PVC film but I have no idea where to source it.  I use the slightly thicker variant found in grocery bags for dust covers or just very thin mylar with almost no tension applied.  

Quote:

Originally Posted by AmarokCZ 

spritzer: any idea what they used on older earspeakers? (e.g. on SR-3?)

Picture taken of a Sony ECR-500. There are sweat screens on both sides, they're made of extremely thin ?PET? film at very low tension with millions of crinkles in it, spaced perhaps a cm away from the metal mesh (which is just outside -and I believe in contact with- the stator), and they have roughly the same radiating area as the diaphragm, perhaps slightly larger.

Hope this helps.

And a beauty shot of the diaphragm just to heat things up a bit. Somebody's gonna make a DIY stat with a scalene pentagonal diaphragm, right...? Riiight?!

I might take the SR-5 apart for you guys if you're truly interested and there's meritable cause, although I wasn't exactly planning on it for myself.

It looks like everybody wrinkles their sweat screens in retail electrostatic headphones. Maybe the industry experts figured something out?

Works great! red before addition, green after

Crumpled up some 2 micron mylar, loosely tensioned it (basically just enough to get it to lay flat with maybe a few millimeters of extra displacement) and glued it on. Turns out crumpled mylar is a really awesome material. It stays relatively rigid in space in that it's not flopping around, but if you even exhale on it from a foot away you can see it displacing significantly. So it has structural rigidity, but virtually no net tension across the whole screen.

Nice job! One year ago I also used wrinkled film to repair my SR-3 and I also didn't noticed any bass roll-off which is quite something since SR-3 have weak low bass even without dust covers.

Also listen to slow sine sweep (~ 20Hz to 200Hz, ~5sec) at high volume. The thing is that I always heard resonances at some frequencies when using creasy film. That's why I'm now using PE film which doesn't resonate and doesn't degrade bass performance too.

I didn't notice any resonances in the sweat screen, but currently my headphones are retired while I develop completely new ones. Some issues came up that I deemed not worth repairing. Done with prototyping, the next edition will look aesthetically good and be made with 100% CNC and laser cut parts to ensure channel matching. Going to make an airbrush mounted above a linear motion table to create perfectly uniform and matched coatings.

Will post results here when done in a few weeks.

dude_500, neat work you've done there and looking forward to future developments!

Do any professionally made headphones have the sweat shield directly exposed to the outside, or is there always another mesh?