Hi all,

I'm working on improvements to my Oktava ML52. I've read all of the
relevant past posts I could find. In particular, I found Michael
Joly's and Scott Dorsey's posts about their experiences helpful. The
consensus indicates replacement of the grill (among other things). I
can see/hear why -- it rings like a bell.

My plan (criticisms/suggestions welcome):

1) remove the hemispherical top and discard
2) cut away the narrow vertical fins in front and back of the shell
3) roll a grill from appropriate material and glue/fasten it in place
inside the modified shell
4) cut a disk of grill material and glue/fasten it in the top ring of
the shell
5) apply some dampening material (e.g., RTV) to the top ring (and
anything else that needs it)

My question is this: should I use wire mesh/cloth or perforated metal?
All of the DIY grills I've seen use wire mesh. On the other hand, I
note that many of the classic ribbon mics (RCA 44 and 77 among others)
use perforated metal plus silk. I haven't heard anyone suggest that
the grills on old RCAs should be replaced to improve the sound, and I
note that modern re-creations like AEAs stick with the perforated
metal. Perhaps this is because the perforated metal is important to
the authentic sound. Or, it could be because perforated metal is a
reasonable choice (assuming the right material, gauge, hole size and
spacing).

Does anyone have advice on this topic? Also, if perforated metal is a
good choice, does anyone have suggestions regarding material,
thickness, hole size and spacing? If I had a 77DX handy, I'd just
measure the hole pattern, but alas...

McMaster lists open area percentage for their perforated metals. I
assume that greater open area is better (more transparent). Is there a
minimum acceptable open area percentage?

Thanks,
Da5id