[Top] [All Lists]

Re: Digital Distortion

Subject: Re: Digital Distortion
From: "evertveldhuis" <>
Date: Sun, 29 Jun 2003 13:05:44 -0000
Hi, To answer both questions:

Normalizing to 50% before you start to edit a file doesn't make much 
sense to me. If for instance the peak level is - 10 dB and the 
average value is -20 dB, and you are gonna normalize to 50 %, you 
will lower the level that much, that you are gonna loose enough bits 
to code the signal. 
If however you make sure that each file has about 10 or 12 dB 
headroom before editing, that would make sense to me ; now you can 
safely do edits and know that you have about 80 dB signal and about 
10 dB headroom.

With some filter settings the total level of the sound is lowered (or 
raised) compared to the situation before the edit. In that case it 
could be that your filtered part has a different level compared to 
the unedit parts before and after your edit. 
[assuming that you selected a small part of a file]
This is VERY audible ; thus unwanted. In that case the pre and post 
normalizing acts like a sort of auto-gain feature.
[also at the same time, the edits are done with max bitwidth thus 
minimal artifacts]
Same goes for compressors ; the actually limit the loud peaks, so the 
peaks are lowered, by choosing the auto-gain feature you make sure 
that the peak levels remain the same ; the RMS will be changed.

Regards, Evert

--- In  Klas Strandberg 
<> wrote:
> And what about programs which normalize automatically? Even twice?
> At my WaveLab, there are squares to mark to enable or 
disable, "normalize
> before" and "normalize after". If I don't remove the marks, the 
> will not only filter, but also normalize the file both before and 
after the
> operation. Automatically. 
> WaveLab is made by Steinberg, which has (as far as I know) an 
> reputation.
> How come they propose such a thing? One may very well think that 
> is a "safe" operation?
> Klas.
> >
> >
> >> I have an opinion on that: never normalize. Never. No need for 
it. At 
> >> the last stage of CD mastering, overall levels might be raised 
so the 
> >> loudest sounds are close to max or limited close to max, but 
> >> as far as you want to go. In intermediate steps, you need 
> >> for processing.
> >> 
> >
> >What about normalizing to 50%. I do this on all my recordings 
before I start 
> >to edit?. Am I making a mistake? I use CoolEdit.
> >
> >Thnaks,
> >
> >John
> >John V. Moore Nature Recordings

> >
> >
> Telinga Microphones, Botarbo,
> S-748 96 Tobo, Sweden.
> Phone & fax int + 295 310 01
> email: 


Your use of Yahoo! Groups is subject to 

<Prev in Thread] Current Thread [Next in Thread>

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU