Are Compressor Presets Good for You?
Mattias Danielsson, June 2012

First of all, lets start with a bold statement: Presets aren't shortcuts to the perfect sound! They might be, but should always be considered starting points rather than solutions to all your troubles. Why? This article will try to explain how to use compressor presets in a sensible way, but the lesson is also applicable to other processors and effects.

First of all well start with an experiment illustrating a very important part of human hearing, that needs to be understood when comparing two sound sources and especially when working with dynamic processors.

Threshold and Gain Parameters

Threshold is the level at which the compressor begins to work. Sometimes the threshold is fixed, and you adjust the "threshold" by adjusting input gain instead.

Make-up gain compensates for the gain loss due to gain reduction in the compressor. Sometimes called output gain.

Please take a moment and listen to the sound examples A and B.
Which one of these samples sounds best? I guess most of you select B. Why? Sample A and B is exactly the same but B is 1 dBFS louder, and thats the way human hearing works. Louder is "always better". This is the field of psychoacoustics, which is about how the human ear and brain interprets and hears sound waves. The important lesson to learn here is that to be able to judge differences between sounds you must level match the sources. This is something that can be tricky to do using meters, since meters (especially peak meters) don't reflect what we hear. Most times you are better off to just use your ears when setting levels.

So when you select a preset and instantly feel that it made everything sound so much better, it could very well be caused by an increase in loudness...
Sound sources vary a lot in signal level, from the super hot loops and samples that tend to be normalized to 0 dBFS, to more sensibly recorded stuff peaking at perhaps -12 to -6 dBFS. It's therefore impossible to design a preset that takes all different source levels into account.

Sound Examples A and B

Sound Examples A and B

If your source level is significantly lower than the level the preset designer used when creating the preset, your compressor will probably be used as a glorified volume control. On the other side, if the level is significantly louder, the resulting sound will be squashed and overly compressed. This means that you need to adjust the threshold to match your source level, and to be able to "objectively" compare the result use the makeup gain/output knob to level match with or without the compresson engaged.

Tempo of your song is also important, if your song has a higher or lower tempo than the song the preset designer used, the attack and release settings might need to be adjusted.

So the lessons learned are: Level match - to make fair A/B comparisons, adjust threshold - to match your sound source.

Customer Service, trumpet player, and sort of the technical go-to guy. Mattias is the guy answering your e-mails and helping you with whatever problems you might have. There are no issues that he hasn't seen before so if you just follow his instructions everything will get sorted out. At night he's usually seen with a soda (Trocadero, a speciality from northern Sweden) engineering behind a live console or playing some kind of game with very small figures or something like that. As long as he has a steady supply of soda he can keep going forever.
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