Choose your compression destiny

One of the most useful pieces of mixing advice I've received lately, is categorising compression into two main purposes:

1. Levelling Compression
2. Enhancing Character / Shaping

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1. Levelling Compression

Soft, gentle and transparent, you don't hear the compression, you are taming the 'STABS' of sound that you want to sound more controlled, and allow you to turn up the channel safely. Allows you to have loud and soft material on one channel, and always audible. Useful as a first stage compressor.

Examples: LA-2A, CL1B

Purpose:

- Taming wild vocals, or a wild bass guitar performance.

- Digitally controlled instruments such as synths, may not benefit as much from this.

2. Enhancing Character / Shaping

Driving, shaping and colouring. You hear the compression, you are shaping the sound envelope and in some cases, driving a vintage compressor hard to add harmonics. Anything from subtle to dramatic changes here.

Examples: Fairchild 670, 1176, default compressor in your DAW

Character:

- Give instruments that recognisable 'compressed' sound.

- Use the character of vintage compressors (including software emulations) to add colour and warmth.

- Use the character of digital compressors to bring out a clean, sharp quality.

- Use each compressor's unique envelope for shaping:

Shaping:

Emphasise the attack, sustain or release of an instrument.

Attack: Bring out a punchy quality

Sustain: Bring out phrases with long, held notes. 

Release: Bring out the breath noise / vocal breaks at the end of each phrase, or even the room reverb of a recording (give a perceptually bigger sound).

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