In our previous installment of Audio FX 101, we went over Reverb, what it does and how to apply it to your tracks. In this installment, we'll talk about Compression and some of the basic functions that are found on most compressors. There will be a second part to this installment that details the process of side chain compression and how it is applied to your tracks that will be out soon. With that said, let's get started with part 1 of Audio FX 101: Compression.
HOW IT WORKS
Compression (also known as Dynamic Range Compression) is the process of altering the dynamic range for a particular sound and/or instrument. For example, a typical compression effect will give a bump to a specific frequency of the signal in an effort to match the frequency level of another on the same instrument. The goal of compression is to bring the signals from across the frequency range of an instrument closer together.
By using compression, we also get a slight bump in volume for the particular track, which could be useful for mixing purposes. Gain can be used on a specific track, instrument bus or even a master track that brings everything together. While it may sound like a great effect to use on everything, you must be cautious of how you use compression in your project file.
Using too much compression could "squash" the natural signal of whatever track you're using it on. For example, you may have put a compressor on an instrument that had a naturally rich high-frequency range. If that instrument is too compressed, the effect could squash the dynamic range of the instrument and take away the natural elements of what makes that instrument distinct in the first place.
While all compressors may have their distinct setup and flavor, most of them share common functions that help dial in your ideal compression effect. The next section will describe some of those common functions and what they do to help give you the right amount of compression that you need.
COMMON FUNCTIONS ON A COMPRESSOR
Threshold: Threshold is essentially the level the signal has to be at before the compression takes effect. The function is measured in dB (decibels). For example, if you set the compression threshold at -30 dB, everything above that number will be compressed.
Ratio: Controls the amount of compression that is used on a particular track. If the ratio is low, the amount of compression being applied to the track is low. The more the ratio function is used, the more the signal will be compressed. Like the Threshold function, ratio is measured in dB. If there is no compression being applied to the track, the ratio is 1:1. When the ratio is raised, the left-hand number will read the amount of sound that goes over the threshold while the right-hand number reads the amount of output given above the threshold.
Attack: Controls how quickly the compression is used on the signal. Most compressor plugins measure attack time in ms (Milliseconds).
Release: Release is the compliment to the attack function. If the attack function reads how quickly it takes for the signal to get compressed, release reads how quickly the signal returns below the threshold. This function is also measured in ms.
Gain: The gain function on a compressor helps bring the level of the compressed signal up. The makeup gain usually serves as a nice boost for the signal and helps it stand on its own in the mix. It's a helpful function to have if your compressed signal attenuates the signal too much.
As for the plug-ins themselves, I have listed three popular compression based plug-ins below that could fit a variety of needs.
POPULAR COMPRESSION PLUGINS
Plug-in: Nicky Romero Kickstart
Creator: Xfer Records
Price: Free download
Plug-in: Sausage Fattener
Creator: Dada Life
Hopefully, you have a better understanding of how compression works and how some of the basic functions can change a track. Stay tuned for part two where I detail the process of side chain compression and how you could apply that technique to all of your songs!