Audio Compression Explained: What is an audio compressor?
A compressor is a plugin or a piece of hardware that reduces the dynamic range of an audio signal. It does this by turning down the loud parts of a signal.
Audio Compression Explained: Why would you use compression?
Well, there’s nothing wrong with music having a strong dynamic range. In fact, dynamic range is often the very thing that makes music interesting and exciting to listen to. But on a practical level, large changes in dynamics can cause a problem. Imagine a scenario where a singer performs some parts of a song loudly, and other parts quietly. Where do you set the fader? If you set it to the right level during loud parts, then the level will be too quiet when the singer performs quietly. But if you set it to the correct level for the quiet parts, the vocals will be too loud when the singer performs loudly.
The answer, is to use compression to reduce the difference between the loud parts and the quiet parts. A compressor reduces this difference by automatically turning the loud parts down for you. Now, you could of course automate the level of the fader to turn it up or down according to how loud the singer is performing, but with a large track count, and with all of the tracks having varying dynamics, that’s a lot of automation to carry out. So a compressor does this job for you.
Audio Compression Explained: How do you use a compressor?
The great thing about compressors is that they offer you a huge amount of control over the way that compression is applied. You decide what volume level the compression kicks in at. That means you can let everything below a certain level remain uncompressed, and have the compressor kick in only when the signal breaches your set level. You can also tell the compressor how much compression should be applied once the signal breaches that level. So you could have the compressor turn the signal down a lot, or only a little.
You also control how quickly the compressor kicks in to action to turn down a loud part, how quickly the full amount of compression is applied, and how quickly the compressor stops compressing the signal once the loud part has passed. Finally, you can turn up the level of the signal after it has been compressed. Having control of these settings let’s you take full control over the way the compression you apply to a signal sounds.
Audio Compression Explained: Conclusion:
So, that’s audio compression explained. As you can see, the function of compression is not all that complicated. You can apply compression to any audio signal, and have it automatically turn down the loud parts of a signal in exactly the way you want. This gives you a more even and consistent audio signal as the signal will now vary less in dynamic range.
Do you use compression a lot in your mixes or masters? Do you prefer light compression, heavy compression, or somewhere in between? Perhaps you avoid using compression at all? Please share your thoughts in the comments section below.