<<And it's true that small electret microphones do not perform up to
the standard of the better studio microphones.>>
I think it might be useful to point out here that "lavaliere" or
miniature capsule microphones & "electret" are not synonymous, as has
been implied in previous posts to this thread. "Electret" is merely a
type of condenser (capacitor) mic technology, which utilizes a
permanently biased backplate, as opposed to standard condensers which
require an external voltage to bias the backplate. The Shure SM81,
which is a mainstay of the sound reinforcement world, is an electret
condenser mic, but it is not a miniature or lavaliere design.
<<I don't believe that the performance of most of these microphones
is limited at all by the physics of microphones.>>
The noise vs diaphragm size question is not controversial nor a
subject of debate within the the community of those who design,
modify or repair condenser mics. Have you a scientific rebuttal to
what is accepted knowledge on this?
<<I think that they could be substantially improved if noise were the
specification that people care about. But lavaliere microphones are
generally made from capsules that were either designed for hearing
aids, or are the better types that are the same ones as used in cell
phones and answering machines. Noise just isn't something that the
big makers of electret microphones care much
about.>>
I think you would find some disagreement on this point from the
manufacturers. Miniature capsule mics are the primary transducer for
the majority of film & television dialogue recording, which is an
industry wherein no expense is spared to obtain technical
improvements in quality. The makers of these mics cannot
realistically be seen as lacking in concern for the noise spec of
lavaliere mics, as any firm which achieved a performance breakthrough
would be rewarded with a substantial bit of high profile business.
No, the high priced miniature capsules on the market are subject to
the same limitations as the budget brands & none of them have broken
the 20db self noise barrier, that I'm aware of. The quietest large
diaphragm mics are as much as 14db quieter than this. And it's not a
matter of not enough money being spent to buy lower noise. The
quietest mic in the Neumann catalog is their least expensive model.
Scott Fraser
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