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Old 01-21-2009, 04:28 PM
O.G. Killa's Avatar
O.G. Killa O.G. Killa is offline
Join Date: Oct 2002
Location: Los Angeles
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Default Re: Normalizing vs Compression or Limiting

Originally Posted by DrFord View Post
Here's what I think you aren't getting, when you apply normalization, you are simply adding or removing gain from source material until it's loudest peak (in peak mode) is whatever you set.

Ex. loudest peak is -4.1db. You desire to have the loudest peak equal -2.0. (maybe you recorded a stereo signal and your mic pre's weren't set equally, so you want the 2 sides to match up)

Normalizing in peak mode would simply ad +2.1db of gain to your overall region.

In this example no tonal shaping, no coloring, no compression characteristics, no transient modification, no compression whatsoever would happen.

So to answer your question, normalizing has nothing to do with compression or limiting. It is simply a function of gain. However, OG has described the RMS mode, which I will defer back to him on because he knows his sh*t.

We can go round and round on this, but if you want the characteristics of compression, you need to use a compressor. Limiting? Use a compressor on 20:1.

Normalizing isn't lazy, it's a tool to be used for the right function. That function typically has nothing to do with compression, it has to do with adding and removing gain with an automated process. Personally I don't use it. I would rather use my ears and eyes. Plus it can cause errors.

However, it has its uses - again, refer to OG's post.

The Dr is right on the money. Normalizing is not an "algorithm". It is not compression. It is not limiting. It is simply GAIN adjustment across the whole file uniformly.

Normalizing is the process of looking at your audio, determining it's maximum peak value and it's RMS value, and then adjusting it's OVERALL level based on that.

As Dr Ford mentioned... if you recorded a snare drum for example, the first hit reached a max level of -6.2dB, the next one -8.9dB and the third -4.5dB. One use of normalizing is to analyze the recording to find that your loudest peak is -4.5dB. Then to normalize the file to 0dB, the normalize plugin would bring the WHOLE FILE up by 4.5 dB. This would make the first peak -2.3dB, the second 4.4dB and the third 0dB. Or you could say you wanted to normalize the file to -10dB. The normalize plugin would then bring the whole file down by 5.5dB. The first peak would then be -11.7dB, the second -14.4 dB and the third -10dB.

normalizing using RMS is the same thing, except you are using average level instead of peak level. Mastering engineers sometimes do this after they have mastered an album. Every track is peak limited to -0.2dB (usually), but one song might still feel louder than the others... when they analyze it's RMS level they might find it's RMS level is 2 dB louder than every other song on the CD. So they Normalize that one track to the same RMS level as the rest of the CD (and in doing so, make that one track quieter, and the peaks come down as well).

Compression is a different animal. Compression actually makes the peaks softer but leaves the quieter sections uneffected. This allows you to then turn the overall volume up because the peaks are lower, but the "distance" or dynamic range between the peaks and quieter material is now smaller. Normailzing DOES NOT change that relationship/distance/dynamic range, and that's how it differs from compression.
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