Compressors are used to obtain a more consistent level by reducing loud parts of the recording without squashing the peaks. This allows you to increase the level of the quieter parts without making the entire instrument or voice too loud.
Correct use of a compressor is a great route to that elusive professional sound. Follow the steps below and you will soon learn how to get excellent results every time:
Compressors usually have a ratio of 20:1 or less and allow control of:
- Attack – the time delay before the compressor kicks in
- Release – the time it takes for the compression to tail off
- Ratio – the amount of compression
- Threshold – the level at which the compressor is triggered.
Set the attack to shortest, the release to fastest, ratio to maximum and the threshold to very sensitive. This will allow us to hear the effects of the compressor.
Having made these initial settings we can now begin fine-tuning the parameters to achieve the best settings for the particular instrument or vocal we are working with:
- Play with the attack until you achieve the desired thickness or fatness of the sound. The slower or longer the attack time, the fatter the sound will be. Listen to how the sound changes as you increase or decrease the attack time. Imagine a plectrum striking a guitar string. If the attack is set short the string will sound soft and thin whereas, if the attack is set long it will sound thicker and chunkier.
- Once you are happy with the thickness of the sound, set the release time so that you can hear the sound bouncing back or rising up at you as the compression tails off. Try to set this so that it feels right and grooves with the other instruments. As the name suggests, the release is the time it takes for the compressor to release the sound from a compressed state.
- Now, reduce the ratio so that the sound isn’t too squashed. A ratio of somewhere between 3:1 and 6:1 should be good for most sounds. Set it so that it feels nice and sounds musical.
- Finally, set the threshold to less sensitive so that only the loudest parts of the audio trigger the compressor.
There you have it, your easy route to great compression results every time.
Note: If your compressor only has an input gain control and a threshold control, then the ratio, attack and release times are set automatically. The input level will determine the ratio.