> Since we now often have 24-bits of dynamic range (in actual practice as m=
uch
> as 22-bits of dynamic range), shouldn't we be recording at the
> recorder/pre-amp's lowest noise condition and not at the maximum gain
> setting? We can then raise levels without adding any noise, after
> recording using in our audio editting program.
>
> If you have adequate dynamic range, it's almost always self-defeating to =
add
> gain in the analog domain.
>
> So I'm curious why you measure noise at maximum gain setting instead of a=
t
> the gain setting that has lowest noise?
Hi Len,
Yes, at least in theory, it would be nice to do it that way. Unfortunately,=
all real-world recorders that I have tested so far exhibit an increased no=
ise floor at the lower gain settings.
In addition to that, the advertized 24 bit recording options of most record=
ers are more or less useless at least for nature recording with its relativ=
ely low sound levels. Note that we have discussed this issue here several t=
imes.
As far as I understand, even the most expensive field recorders only provid=
e a dynamic range of about 110 dB, which corresponds to a theoretic bit dep=
th of 19 bits only. But again, it is not guaranteed that this advertized dy=
namic range is achieved on all available gain settings. The problem here is=
the lower end of the dynamic range at the low gain settings, where the pre=
amp noise floor usually exceeds the inherent noise floor of the microphone.=
For this reason, one must increase the preamp gain in order to get rid of =
the recorder noise component.
Regards,
Raimund
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