What Is Dithering and Why Use It in Audio Mastering?

What Is Dithering and Why Use It in Audio Mastering?

During audio mastering, it’s possible to introduce unwanted distortion effects into the audio. One of the processes a mastering engineer might use to remove this kind of distortion is known as dithering.

But what exactly is dither and dithering? I’ll explain in this article.

What Is Dither?

Analog studio sound mixer closeup with laptop and sound wave form in the background

Dither is one of the more complicated concepts to understand in audio mastering. Essentially, dither is low-volume noise that’s mixed into a digital audio file when it’s converted from a higher bit resolution and into a lower one.

When you do this kind of conversion, it can introduce what’s known as truncation distortion. If this kind of distortion isn’t prevented, it can lead to a digital audio file that’s downright unpleasant to listen to.

What Is Bit Depth?

In the world of digital audio, the bit depth refers to the number of values available to represent the amplitude of a single audio sample. The higher the bitrate, the more DBs of dynamic range each sample will have.

When you export a file to a lower bitrate, there are effectively now fewer values available for the file to depict the dynamic range of the audio. This results in a “rounding off” of the audio; since the bitrate has been reduced, the amplitude of each sample can no longer be measured in as much detail.

This “rounding off” affects the shape of the waveform, resulting in distortion.

So How Does Dithering Prevent This?

Truncation distortion creates harmonics that are correlated to the initial source; these harmonics make it quite obvious to hear. With dithering, you introduce a noise that’s random, which effectively covers up the truncation distortion.

So why not just keep your files at 24-bit and remove the need of experiencing any truncation distortion? Unfortunately, the vast majority of playback devices are going to be 16-bit. If you try to play a 24-bit audio file on one of these devices, it isn’t going to sound good.

When to Dither in Audio Mastering

Essentially, you need to use dithering when you’re mastering the file at a lower bitrate than you worked at during the production stage. Say you recorded in 24-bit and you’re mastering the audio file in 16-bit; you need to use dithering. On the other hand, if you were recording and producing in 16-bit and you bounce it at 16-bit, you don’t need to dither.

If you’re sending a track to a mastering engineer, you should never export it at a lower bitrate than the one you were working at, as this will mean the audio is already damaged before the engineer even starts working on it.

Work with a Professional Mastering Engineer

So now you understand a little more about what dithering is. If you’re a music producer, consider working with a professional mastering engineer instead of trying to master your own music. This can help your tracks sound more refined and high quality.

Need a professional mastering engineer? Then get in touch with me today.