The way I do it is to create a pink noise field in the studio with as many =
speakers as possible (to make it diffuse) and sending different (not in pha=
se) pink noise to each speaker (again for diffusion). I band-pass the pink =
noise so it's 200 Hz to 2000 Hz. That's a good range to set levels with bec=
ause it avoids typical irregularities in room response at the low end and s=
peaker variations in the high end.
I use a calibrated sound level meter to set this noise field to 64 dBA at a=
marked (I use a mic stand) measuring point.
Then I record the noise at the measuring point on my field rig or rigs, at =
the recording gain or gains that I use in the field. I name each calibratio=
n recording with the name of the mic and recorder, gain, and "64dBA calibra=
tion."
I can then import the calibration recording into a session. I use a meterin=
g plug-in set to RMS to measure the digital level of the sound of interest,=
and to measure the level of the calibration recording. The difference tell=
s me the difference from 64 dBA. I can use the calibration recording over a=
nd over in different sessions as long as the mic and recorder setup it was =
made with are in use.
-Dan
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