well
I got a nice response
from the manufacture
and a wait a bit more from my reply
but so far here is more info
The response is 40-16Khz.
3/4” x 3”
(which I would guess would be = ~19-20mmX ~75-76mm)not to totally quote the response but
like this
from an outgrowth of the condensers that we have had in our MTD drum packs. the response convinced us to release them separately and in pairs. we have called these mics entry-level not having these specs have not been a problem when people have heard these mics. we have found that specs frequently don’t tell the whole story, and some companies tend to stretch the truth. our definition of entry-level says that a professional still has to be able to get a good sound from the product
also they should be updating their web site soon
it looks like they have a quite nice headphone line
any more info I find out
I'll up date
-- Ian