Quote:
Originally Posted by KevWind
Would the room noise mask the self noise, wouldn't the 19 db self noise, be added to (as opposed to, subtracting from ) the ambient room noise, in the recording ?
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Basically, the mic's self noise is telling you how much of the low level signal you won't be able to use because it's all masked by noise. IOW, your source needs to be louder (significantly) than the noise floor so that you don't hear the noise floor. Think of it like this: in this case you can't hear the first 20dB or so of room noise because it's all masked by the mic's self-noise.
For reference, a normal conversation is about 60dB. The typical live room of a good commercial studio is about 30dB. Keep in mind that 60dB is
not twice as loud as 30dB. Since dBSPL is a logarithmic scale, you double power every 6dB. And the SPL means that it's a measurement of Sound Pressure Levels (in Pascals) where 1 Pascal = 94dBSPL.
Generally speaking, self-noise of 20dB and under is pretty respectable. My U87 has somewhere between 23-26 dB of self noise (depending on the polar pattern selected) and no one would say "that's not a good mic buy".
HTH