From: "Aaron Bishop" <[EMAIL PROTECTED]>
Subject: Re: Audio Compression, Normalization Caution
The explanation of the difference between computer compression and audio
compression is quite good and totally accurate, but the reasoning behind
not normalizing is terribly subjective and (in my opinion) incorrect.
We use Sound Forge 4.5 (a most-excellent program if I must say so) to run a
Graphic Dynamics (compression) of about 2.5 to 1 above -12 db. Does a
*wonderful* job of "filling out" the audio and giving it *presence*. Then
I run a light normalization that brings it to 98%...but keep in mind the
normalization doesn't need to do much after the compression is done (in our
case anyway).
It helps that we're pretty much voice-only, too.
Either way, I would much rather have a little too much prescence than
nowhere near enough...an EXTREMELY common problem amongst radio stations
that do a half-assed job putting their audio feed on the web (and, to be
fair to their engineers, don't do a good job training their staff on how to
speak - as opposed to mumble - on the air). Nothing irks me more than to
have my RealPlayer's volume and my speakers' volume cranked to the max and
I'm still having a hard time hearing the audio...esp over the roar of hiss
that comes from that much "gain"
But that's just my opinion, too. I feel you really need to try it both
ways and see what sounds good to you, and preferably to a few impartial
observers.
Aaron Bishop
CW Audio Engineer
[EMAIL PROTECTED]
From: "Harry C. Lewman" <[EMAIL PROTECTED]>
Subject: Audio Compression, Normalization Caution
to the RA group:
[ RF: A useful bit of information, with thanks to Harry for clarifying. ]
I was asked to re-post a small thread about audio compression. Posts here
go from newest to oldest. In response to a question from Alex (see below)
about normalization and recording levels, Steve Sneed wrote (see below)
that he normalized to 95% using Sound Forge editing software.
I strongly disagree with using audio normalization in most cases before
encoding for RA. In comparing RA encoding on identical recordings, I have
found that audible artifacts (static,bumps, etc.) increase as the recording
volume during encoding is increased. In that same manner, a piece of audio
that has been further normalized has a better chance for more distortion
during its playback as a RA file.
The difficulty in explaining this is compounded by the fact that in the
audio world, compression means a different thing than it means in the
encoding and computer file making business.
Here is a quick explanation: (a prior post)
From: "Harry C. Lewman" <[EMAIL PROTECTED]>
Subject: Re: Your RealForum Post
In-Reply-To: <[EMAIL PROTECTED]>
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In the audio world, compression is usually reserved for those actions which
help control the volume at which a sound is recorded or played back. In
its simplest form, it can be called "gain riding" which is just turning up
the volume during a transfer stage from one medium to another. Currently,
there are many automatic ways to do this, and compressors are highly valued
audio tools.
In the computer world, compression may be used to define the amount of size
reduction in a file. This is NOT compression as defined in the audio
world. In the audio world, excessive use of audio compression is very
common, IMHO. Its result is to reduce the dynamic range of a recording so
as to
increase its average loudness.
Normalization, as defined again in the audio world, in software use, is
another form of audio compression and IMHO, should not be used except in
unusual circumstances. I have found that RA conversion sounds much better
when recording levels are kept very low.
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