Peter Shute wrote:
> 1. How do I decide how much to increase the volume by?
> It seems to me that normalising to a particular level
> will have haphazard results because it all depends on
> the loudest sound in the recording.
Generally recordists working with nature, SFX or film sound never normalise=
. If you normalise you have thrown away your baseline for recording. Withou=
t normalisation you can playback all sounds recorded with the same gain str=
ucture and the background noise level (of the hardware) will be the same, a=
s will the points where distortion and clipping occur.
This is why it is so important to determine an optimal gain structure and r=
ecord with correct levels in the first place.
Mastering together finished selections for a CD or other compilation is ano=
ther matter. One must often mix different tracks at different volumes to ac=
count for the overall programme flow or variations in signal-to-noise betwe=
en selections.
> 2. If the above will result in clipping of the loudest
> parts, what should I do about them? Audacity has a Compress
> function which looks like it might help bring them
> down a little without affecting the quieter parts.
Opinions will vary depending on how purist the respondent is. I, for one, w=
ould NOT apply a Compressor, since this will raise the noise floor of the q=
uieter sections. Instead apply a Limiter, which will change only the peaks.=
Soft limiters can work wonders on the occasional peak that is way out of b=
ounds.
> 3. Is there a standard length for fade in times?
No. My best advice is to consider not just the time but the fade curve. A s=
traight curve is almost never appealing. Try logarithmic curves.
> 4. I've noticed that the default vertical scale in Audacity runs from -1 =
to +1 (linear?) whereas in Sound Forge it's in dB.
dB is a ratio scale which more closely maps to how we perceive volume from =
amplitude. I would try to change the Audacity scale.
-- robinparmar.com
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