Compressors are acclaimed as to what imparts character to modern music, and in the beggining that’s hard to grasp. As you learn how to mix you start realising that pros use different kinds of compressors for different things, and you start wondering what really is the difference. Compressors can be essentially divided into four categories. Here is a cheat sheet to help you with your productions and to determine when to use each kind.
– Compression based on peaks;
– Fast attack and release;
– Transparent and thin;
– Used for controling peaks in very percussive tracks – guitars, drums, spiky vocals;
– Transparent buss compression;
– Mastering applications.
– Less sensitive to transients, peaks and sudden spikes;
– Sluggish attack and initially fast release, with a slow return to null state (Some optos have two release knobs);
– Musical and transparent;
– Evening macro-dynamics;
– Used to even out vocals; strings and bass;
– Used with sidechain compression on mix bus to avoid pumping.
– Ratio increases with gain reduction;
– Slow attack and release;
– Warm and rich;
– Great for thickening and warming thin tracks;
– Used in drum tracks, drum buss, vocals, piano and acoustic guitars;
– Used with sidechain compression on mix bus to avoid killing bass.
– Super fast attack and release;
– Punchy and snappy;
– Warm distortion;
– Lot of character;
– Drum busses, snares, kicks, and have a desirable tendency to shoot a lead vocal straight to the front and center of a mix.
– Flexible compressor;
– Distorts low frequencies;
– Fat and saturated sound;
– It saturates more as the input level increases;
– Used for fattening up tracks where you want to keep detail in the mids, like the bass, or horns;
– Used for when you want a character not as gritty as a fet, and more pronounced than a variable-mu.