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Re: Some basic processing questions

Subject: Re: Some basic processing questions
From: "Curt Olson" flipov411
Date: Wed Jan 18, 2012 12:22 pm ((PST))
Robin Parmar has already given helpful replies to your questions, Pete, but=
 I'll add a few thoughts of my own...

> I've started to accumulate a bit of a collection of recordings, and I hav=
e a few basic questions about processing them ready for others to listen to=
.
>
> 1. How do I decide how much to increase the volume by? It seems to me tha=
t normalising to a particular level will have haphazard results because it =
all depends on the loudest sound in the recording. Should I pick a typical =
piece and adjust till its peaks are at some particular level? If so, what l=
evel? Or should I be listening to some sort of reference track and doing it=
 by ear? What I'd like to avoid is the listener having to dive for the volu=
me control because it's too loud or soft.

Good instincts about normalizing, Peter. It is rarely ever good idea, IMO. =
That said, I almost always boost my nature tracks in steps with a combinati=
on of compressor and level-maximizing peak limiter. Not always to full scal=
e, however. Exactly how much is a matter of artistic judgment.

For individual tracks, I tend to think in terms of the loudest peak event i=
n the track, and decide how loud it should be based on where it sits in the=
 overall spectrum of quiet to loud events in real life. I might allow a Blu=
e Jay calling from ten feet above the microphone to peak at -.3dbfs (db rel=
ative to full scale), where the same bird calling from across a small lake =
might not even hit -30 dbfs. It might well be appropriate for a beaver spla=
shing its tail 30 feet away from a microphone on the water's edge to peak a=
t -.3dbfs, where the same event 100 yards across the beaver pond might want=
 to hit only -18dbfs. It's all relative, and it's all  up to you.

> 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 migh=
t help bring them down a little without affecting the quieter parts. Is the=
re a better way? (An example of the problem would be where for a few second=
s a bird sings just a couple of metres from the microphone.)

I use ProTools for all my editing, so I can't speak with much authority abo=
ut Audacity. But in general, I like using a small amount of compression (2-=
3 db) on loud events and also a small amount of peak limiting (another 2-3 =
db) on the loudest events. But keep in mind that some soundscape recordings=
 don't contain individual events loud enough to qualify. Again, it's all re=
lative. And a lot of this comes only by experience, which means potentially=
 a lot of trial and error before you've figured it out for yourself.

> 3. Is there a standard length for fade in times? I randomly picked about =
10 seconds for one, then discovered that too long a fade in tricks the list=
ener into turning up the volume, only to discover in a few seconds that it =
has to be turned down again.

There is no standard fade length, as far as I'm concerned. Some material se=
ems to want shorter fades, other material seems to want longer fades. I'd s=
uggest maybe starting with 10 - 12 seconds and adjust form there as needed.=
 I agree with Robin that linear fades are usually less interesting than log=
arithmic fade 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. Is there any reason to p=
ick one or the other?

Can't help with that one. Sorry.

Curt Olson
http://minnesotasoundscapes.com





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