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Re: comparing mic specifications...

Subject: Re: comparing mic specifications...
From: "cfmspencer" cfmspencer
Date: Wed Jul 5, 2006 7:12 am (PDT)
--- In  Rob Danielson <>
wrote:
>
> At 11:22 PM +0000 7/4/06, cfmspencer wrote:
> >
> >in comparing the likely usefulness of mics for
> >quiet ambient nature recordings, I've been
> >dividing the sensitivity spec figure by the
> >noise spec figure and ranking mics relatively
> >based on the result.
>
> Could this table be trying to "level the playing field" between
> effects of noise and sensitivity?
> Table 3. Output Noise for Condenser Mics (dBu)
> http://www.rane.com/note148.html
> Rob D.

Rob,


thanks for sharing this site, although I do have
a question about table 3.

I am under the impression that a higher sensivitiy
rating is better, all things being equal.
I think of sensitivity as an output rating,
that is, a measure of mic output for a given input/stimulus
to the mic. e.g., if two mics have the same self noise, say 5db, and
one has a higher output, say 50mV versus 25 mV, the one with
50mV output is more useful in recording quiet nature sounds,
 is this true?

I must have it wrong, as this table 3 seems to suggest that
a lower sensitivity rating has lower noise, in a comparison of two
mics with the same db-A self noise rating.  let's use the 6db self
noise column as an example,  a 25mV sens would result in -117.5
result, and a 50mV sens would result in only -112 in Table 3.

note: I'm assuming that the larger (more negative number) is lower
noise due to the comparison of entries on the top row, i.e., 16 db
self noise is -130 and 6 db is -140.

do I have the sensitivity idea backwards, or have I gotten
something else totally wrong?

thanks so much
Clay


>
> >
> >by this method, a Sanken mic with 20db noise
> >and 50mV output would rank higher than a Sennheiser
> >with only 12 db noise and 25mV.
> >
> >does this seem a reasonable way to compare, or is
> >lower noise ultimately more important than higher
> >output?
> >








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