WE ALL KNOW COMPRESSORS ARE FOR CONTROLLING SIGNAL VOLUME, BUT IN REALITY THEY DO MUCH MORE
AUTOMATION VS COMPRESSION. Compressors work best when used for their creative characteristics rather than just basic level control, so before you compress your audio it‘s good technique to first track the levels and automate the volume to achieve the overall dynamic feel you want throughout the duration of the song. Don‘t rely on a compressor to do everything. If you‘ve properly automated your audio levels then you will get better results from your compressor. You need to play your track through first and adjust the volume curve to ride the signal and manually draw out the level you want for the part in the mix. This can be done on the fly or by directly drawing into the automation channel. Once you‘re happy with your level automation then you can start using compression.
SECRET USES OF THE COMPRESSOR: Compressors introduce a lot of character and feeling into a sound. The transient shape can feel beautiful and many compressors introduce extra harmonic content which enriches your sound. Try not to think of compressors as level controllers and more as sound design tools. Understanding how they can be used for sound design and learning how to get the most out of each compressor will be a pivotal moment in your mix.
TRANSIENT RESPONSE: The transient response defines the type of punch the compressor gives, and the way the transient and release response is handled varies with every compressor. These micro-subtitles in the curve response are what gives each compressor it‘s unique characteristic. You need to know how each compressor sounds when it‘s processing transients in order to choose which one is right for your sound, so spend some time experimenting with a variety of compressors before ever using one in a mix. Then when mix time comes you are able to select your compressor wisely, based on what you are trying to achieve.
HARMONIC COLOURING: Along with the response and transient curve, the characteristics of a compressor are also defined by the harmonic content they introduce into a signal. Every compressor colours the sound differently, so spend some time learning about the harmonic response of your favourite compressors and you‘ll start being able to enhance your mix in ways you hadn‘t thought of before. For example, a Fairchild 670 compressor can be much more effective for thickening and colouring bass frequencies, than it is for controlling levels.
SERIAL COMPRESSION CHAIN: Using a serial chain of compressors can create a very aesthetically pleasing sound. Compressors often work best when used subtly, so if you want to achieve a strongly compressed sound rather than crank the settings to the max it can be much more effective to use a serial chain of 2 or 3 compressors with more subtle settings. This just has a certain magic panache to it which has to be heard to be fully appreciated.
PARALLEL COMPRESSION: If you want to have some of the tonal qualities of a heavily compressed sound but you also want to preserve some of the natural feel and shape of the original signal then you can use parallel compression. You do this by mixing a heavily compressed channel alongside the original signal by using the wet/dry ratio on your compressor (if it has one) or on a parallel channel. This really opens up more creative possibilities and you might just achieve the sound you are looking for, so get in there an experiment.
COMPRESSION AFTER FX: One of my favourite production techniques is to apply my main compression at the end of my seriel chain of effects, after delay and reverb. This is because I find the sound achieve when the compressor starts compressing the fx in the gaps in audio is very pleasing to my ear and producing really cool sounds and artifacts. Highly recommended.