How To Use Audio Compression and Dynamic Range

The majority of people know what Audio Compression is and what is does but the minority of people know how to use it. There are two different types of compression when dealing with audio:

• Audio Data Compression

• Dynamic Range Compression

When producing, we use Dynamic Range Compression. Firstly, to understand Dynamic Range Compression, you must understand what Dynamic Range is. Dynamic Range is the difference between the quietest, smallest sound we can hear and the loudest sound. The dynamic range of human hearing is the quietest sound we can hear and the loudest sound we can hear.

We measure Dynamic Range in decibels, you may have recognised the symbol of decibels which is dB. If you were to express the Dynamic Range of a certain instrument you would write (the loudest sound it gives off dB). The Dynamic Range of a CD player is 96 dB because that is the loudest sound it gives off.

How can you actually use Compression?

So now you know about dynamic range, you can now begin to understand how to use sound compression in your DAW.  Audio compression is one of the most important effects within electronic music. It will help your song massively; it is a vital part of the mixing stage. Compression reduces the dynamic range of sounds. To make it simpler, it is a form of automatic volume. You set the threshold and when the sound reaches this threshold, the sound will decrease in volume based on the setting you choose.

Features of a compressor and what they do:

Threshold

This sets the dB level at which the compressor will kick in. Once the threshold has been reached, compression will start, reducing the volume of the sound based on the ratio, type, attack and release settings you set yourself.

Ratio

The amount of the volume will be decreased by is determined by the ratio set. For example, a ratio of 2:1 means that when the volume increases by 2dB, the part of the volume above the threshold will only decrease by 1dB.

Gain

This controls the amount of gain that will be added or taken away from the compressed sound. The higher the number, the more gain will be given to the sound that is over the threshold.

Attack

The attack controls the time it takes to reach 100% compression once the sound has gone past the threshold. Fast attack means that the sound compression will happen more or less straight away. A slow attack means that the compression will be increased over time.

Release

The release sets the time that the compressor will stop acting after the level has gone back below the threshold. Short release time means it takes longer to go below the threshold, however, a short release time could affect sound quality as there are fast changes in volume. A long release time means that they will be less distortion, but small variations in the sound will be ignored.

Type

There are 8 different “Types”: Hard, Medium, Vintage, Soft, Hard/R, Medium/R, Vintage/R, Soft/R. They control the knee type and TCR. The knee type determines the dynamic range, in which the audio compression changes to the value chosen. Choosing a hard knee setting acts the same as a fast attack, it means that compression takes place almost immediately after the threshold has been reached. A soft knee setting does the same as slow attack, the sound compression is gradually applied.

I hope this article has helped you to understand better what is audio compression and how to use it to get the best results. It is essential to know these things because compression can cause major sound-quality damage. Feel free to share this article with your friends using the social buttons below.

Also See: Best Free VST Compressor Plugins