from what ron and scott are saying I understand, low self noise is 17 dB(A) or
quieter, and
there are no such quiet very small mics because as the diaphragm size decreases
noise
increases.
bruce meyers, president of DBA, US, explained the browian movement as the noise
of air
molecules bumping together. when the space between the diaphragm and metal is
decreased, the bumping is amplified.
he also said a dirty little secret is that there are no ADS (?) standards for
testing mic self
noise. DBA is working for the creation of standards. six mic manufacturers got
together to
test their mics. each used their own equipment and methodologies. DPA which
uses the
best testing equipment, he said, tested their mics at 20 dB(A), the other five,
measured 10
dB(A). The five companies tested the DBA mic or mics at 10 dB(A) with their
equipment
and methods. DBA tested the others at 30 dB(A) with their
equipment/methodology. He
said you can estimate the DBA mics to be 5 to 10 dB(A) quieter than other mic
specs.
Bruce also said there is no method of showing where in the spec, noise will
occur. the
human ear hears more in the mid range.
he recommends the 4060 for nature recording which has 23 dB(A) according to
their
standards.
What do you think about his comments on DBA tests? It would indicate the 4060
mics are
quiet according to the 17 dB(A) or quieter definition.
Lily
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