> Related to mic low noise,
> Have you ever used cross correlation to determine very low noise levels?
> Cross correlating both left and right channels ? I recently ran into this
> article:-
>
> http://www.gracey.com/downloads/nor_low_noise.pdf
>
> Which is about measuring very low sound pressure levels. I measured my
> anechoic chamber with a pair of 100mV/PA mics interesting results.
Hi Mike,
That's quite interesting. So far I have had to need to measure such extremely
low noise levels.
Bye the way, this issue of uncorrelated noise components is also relevant when
comparing recorders with both balanced and unbalanced microphone inputs.
Balanced (transformerless) inputs have the advantage that they inherently
provide a lower noise floor (-3 dB) than their unbalanced counterparts
(assuming that the same op amps are being used).
Theoretically, the noise floor of an unbalanced stereo microphone input could
also be reduced by 3 dB if the output of a mono microphone was fed into both
the left and right stereo inputs of the recorder. The two tracks could then be
added by software in order to benefit from the reduced overall noise floor.
Regards,
Raimund
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