What is Audio Saturation? & How to Use it

Audio saturation has long been used by music producers to create warmer and fuller sounding mixes. As one of the most powerful music mixing and mastering tools, audio saturation makes a huge difference to your sound. 

When used correctly, audio saturation has the ability to transform a dull and empty mix into an exciting and dynamically mastered song. This works by subtly overloading sounds to create pleasant harmonic distortions.

Learn how to make your music more complete with our guide to audio saturation.

What is audio saturation in music?

Audio saturation is an audio effect that adds subtle harmonic distortion and character to music mixes. Saturation makes music sound more pleasing, combining soft compression and harmonic generation to enhance the warmth and presence of sounds.

Types of saturation include tape, tubes, transistors and circuit processing.

Saturation originates from traditional methods of analog music production, where recordings were processed through several pieces of hardware. This gave sounds a fuller and warmer quality. Soon enough, sound engineers discovered that overloading tape machines, amps, preamp transistors and tubes with increased audio signals creates saturation.

To this day, sound engineers and mixers apply saturation effects to add warmth, character and presence to a track. It can be applied for both subtle and more drastic effects, making audio saturation an extremely creative tool in music production. Modern audio saturation is usually applied using software VST plugins, such as FabFilter Saturn 2.

What’s the difference between saturation and distortion?

The main difference between saturation and distortion is that saturated sounds are softer, whereas distorted sounds are harsher. Audio saturation is the combination of compression and distortion, created by overloading electrical system components. Audio distortion alters the shape of a sound waveform, modifying its tonality.

In the music world, the terms are sometimes used interchangeably. Both saturation and distortion result in a thicker and fuzzier sound, but there are major differences in the processes used to achieve this. Additionally, the end result of each process is much different. Saturated audio is not as fuzzy and harsh as distorted audio.

Common terms used to describe both processes include:

• Saturation
• Colouration
• Distortion
• Harmonic generation
• Crunch
• Fuzz
• Overdrive

And many more. These terms are often used to describe both saturation and distortion audio effects, which is why audio saturation and distortion are sometimes terms that are used interchangeably.

Types of audio saturation

To understand how to use audio saturation in music production, it is important to understand the different types of saturation that can be applied to sound mixes. 

Each type of saturation processing will result in different effects. You’ll find a range of saturation VST plugins that specifically cater for each type, so it is useful to know which modes of saturation are suitable for the sound you wish to create.

Tape saturation

Tape saturation is one of the most popular methods of saturation in sound design. Tape saturation plugins simulate the sound of audio signals being processed through an analog tape machine. This adds harmonic frequencies to the audio, resulting in a thicker sound.

Tape saturation subtly reigns in high-end frequencies, whilst boosting low end frequencies. Most plugins will also apply a smooth compression to the audio signal. This can create a punchier sound, with more fatness and depth.

All together, this results in a sound with more dimension, character and warmth. Tape saturation is a great processing tool for warm lo-fi, ambient or even experimental music mixes.

Tube saturation

Tube saturation plugins simulate the sound of audio signals being driven through tube amps. These plugins add harmonic frequencies alongside subtle compression, resulting in a warmer and musical sound. 

Many producers and artists use tube saturation plugins as they create a deeper and fuller sound than tape saturation plugins. This is because tape saturation adds 2nd order harmonics, subtly adding both higher and lower octaves of the sound into your mix. 

Tube saturation adds distortion to your music, but when pushed too far, can result in an aggressively gritty sound. Too much tube saturation can overload your mix, so use it in moderation.

Transistor saturation

Transistor saturation plugins simulate the sound of audio signals being processed through transistors-based circuits.

This adds harmonic distortion to sounds, although with a harder-clipping compression. Transistor saturation effects will produce a fuzzy, gritty sound with lots of texture. 

This type of saturation adds emphasis to higher harmonics, resulting in a less punchy and dynamic sound when pushed too hard. Using transistor saturation more subtly however will result in a smoother distortion. 

What does audio saturation do?

Audio saturation can improve your mix by adding warmth and character to your sound. Saturation can also be used to create a punchier mix, where lower harmonic frequencies are boosted alongside soft compression.

Using audio saturation makes your mix sound more musical, adding the textural and rhythmic subtleties that make music more enjoyable. Many producers use saturation plugins to recreate the warmth and soul of analog recorded music. Think subtle fuzz, thickness and energy.

Audio saturation can improve your mix in a number of ways depending on the kind of sound you want to create. 

Whether you want to make your digitally processed track sound fuller and more ‘human’, or want to distort your sounds into something more extreme, audio saturation is the perfect tool to get creative with.

When should you use saturation?

Saturation can be used on all types of sounds and instruments. It can be used to thicken up audio during mixing, or used as a creative effect (like a vintage radio speaker). Saturation is a great tool for capturing analog sound characters. For instance, tube and tape saturation help create vintage sounds.

If you are just uncovering the wonders of audio saturation, try out some of the best free saturation plugins to help you get started

Saturation can also be used on your mix's bus groups and your master track to create a more cohesive and present mix. 

Drums bus

One of the most difficult aspects of digitally producing drum tracks is getting all of the elements to fit together. Kicks, hats, snares, percussion - there are a lot of sounds going on. 

Adding audio saturation to your drum bus can help create a more cohesive drum sound in your mix. Tape saturation will help smoothen any harsh high end frequencies, and soften any disruptive transients. 

Drum bus saturation is a great way to add excitement to your track and ensure that your drums flow perfectly throughout the mix. 

Basslines

For those who like their bass fat, tube saturation is the way to do it. Adding tube saturation to your bass tracks will fill out the lower end frequencies, resulting in a thicker and punchier bassline.

Vocals

Vocals are element of the mix that you’d usually want at the forefront - saturation is a great way to make vocals more present and sound much more interesting. 

What does saturation do for vocals?

Audio saturation for vocals adds subtle forms of soft-clipping compression and harmonic generation. This makes vocals sound fuller, louder and more complete. Vocal saturation adds presence, warmth and character, making dull and dry vocals sound more professional.

Vocal saturation can also help control transients through its subtle compression.

Synths

Many synths can sound extremely clean and unprocessed. When not treated properly, virtual synths can lack character and often sound very generic. 

Applying saturation to your synth tracks can add harmonic mid and high frequencies, making them more present in the mix. Synth saturation across mid range frequencies can also help your synth tracks blend into your mix, perfect for softer genres such as ambient music. 

Guitars

Saturating your guitar track is a great way to add more body to your guitar sounds. Adding audio saturation to darker guitar sounds can subtly brighten the sound. For these darker sounds, saturate sound frequencies within the 3kHz to 20kHz range. 

Similarly, if your guitar is lacking presence, try saturating your guitar track within the 500Hz to 5kHz range.

Effects

Although saturation is an audio effect itself, adding saturation to other effects can help you get really creative with sound design. 

This can add additional texture and depth to your effects, or simply make them sound thicker.

Master

Audio saturation can be used to add that final touch to your master mix. Alongside important audio processing tools, such as EQ, saturation can make your final master track sound more unified and cohesive.

Adding audio saturation across your master track will result in a more analog sound for your whole mix. Be careful not to apply too much saturation here, as this could cause unpleasant audio distortion.

When used right, saturation on your master track can be a game changer. By adding subtle harmonic frequencies to your final sound, all at once, all of your instruments will sound fuller and more alive. 

Using a multi-band saturation plugin, such as FabFilter Saturn 2 will help you identify which audio frequencies are lacking thickness. Once identified, saturate those frequencies for a fuller mix. For example, if you noticed that bass frequencies were lacking thickness, try saturating those in your master track.

You can see an example of how to use multi-band saturation plugins in the video below.

Do you need saturation on every track?

Audio saturation is not necessary for every track. If saturation does not make your mix sound better, despite how much you alter the plug-in, don't use it. Saturation can add fullness and texture to your sounds, though it can also make certain sounds and instruments sound slightly duller in some cases.

Conclusion

If you have ever wondered what makes other music sound more complete than yours, chances are that they've used saturation to liven up their track. Audio saturation can add that important finishing touch to your mix, adding the analog kind of character that digital sounds often lack.

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