Rob Danielson wrote:
> I don't understand why the mics with lower sensitivity appear to
have
> lower effective noise on the Rane chart. I asked about this some
time
> ago; maybe someone knows.
Hi Rob,
The dBu noise floor values on the Rane chart are absolute noise
voltage levels that depend on both the equivalent SPL noise level
(the "dBA" specification) and the sensitivity (the "mV/Pa"
specification) of the microphone. See also the Rane table 3 at
http://www.rane.com/note148.html
Imagine you had two different microphones that have both the same
noise floor specification of 14 dBA, but different sensitivities of
20 mV/Pa and 50 mV/Pa. The 20 mV/Pa model provides a noise voltage
floor of -112 dBu. The 50 mV/Pa model produces a higher absolute
noise voltage of -104 dBu. The 50 mV/Pa model could just be
interpreted as a 20 mV/Pa microphone with an additional ("zero
noise") 8 dB preamplifier.
So, what does this mean to us? If you already have a recorder with a
mediocre preampilfier, you should select the microphone with the best
(highest) "mV/Pa" specification. In other words, a more sensitive
microphone already includes a "zero noise" preamplifier that lowers
the noise performance requirements on the recorder side.
Regards,
Raimund
"While a picture is worth a thousand words, a
sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause
------------------------------------------------------------------------
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/naturerecordists/
<*> Your email settings:
Digest Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/naturerecordists/join
(Yahoo! ID required)
<*> To change settings via email:
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
------------------------------------------------------------------------
|