What Is Audio Saturation? (Explained)

One of the most popular effects in recent times, saturation is everywhere but, unfortunately, not many people understand it.

This article will explain what saturation is as well as the different types of saturation. We’ll also run through some awesome tips and tricks, so you can saturate your audio with confidence.

What Is Saturation In Music

Saturation is a very subtle form of distortion usually used to bring presence, “warmth” and analog harmonics to your audio. Saturation comes from the old days of analog hardware, with your signal running through different pieces of hardware.

This signal path is what created the warm and fuzzy sound, so characteristic of vintage analog hardware. Soon enough, engineers found out they can overload tape machines, amp and preamp transistors and tubes, to create saturation.

To this day, saturation is an incredibly popular effect, and available in most DAWs. Used on anything from vocals, to drums, to entire mix buses and masters, saturation can give character and texture to your sound.

It can be used for both subtle and extreme applications, bringing something unique to the table no matter what you do.

Types of Saturation

There are 3 main types of saturation:

  1. Tape Saturation – Good for “rounding” off transients, and adding lo-fi warmth.
  2. Tube Saturation – Edgier than tape, tube saturation is used to bring in harmonics and crunch.
  3. Transistor Saturation – Used to introduce texture, and a gritty, fuzzy sound to signal.

Now let’s look into these 3 types a little more in-depth.

Tape Saturation

waves tape saturation plugin

Tape Saturation is quite simple. It’s essentially the overloading of the tape that creates the harmonics we’re looking for.

Magnetic Tape has a certain amount of magnetic particles in it.

The orientation of these particles, determines the output signal. Basically, if you write to tape, you’re reorganizing the particles to set paramters, so that it can be played back.

A loud signal will require the use of the majority of available particles, while a quiet signal will use less. Tape saturation is what occurs, when you don’t have any particles free to be re-arranged.

This is the point when your saturation starts to occur.

An overloaded tape starts introducing compression alongside generating harmonics, which in other words is saturation.

Tape loses it’s magnetic particles over time, so older tape will have a lower threshold of saturation, and require less volume.

This is all well and good if you’re working with an actual tape machine, but like most of us, we usually get to use only digital emulations of tape saturation.

Tape saturation plugins, usually subtly reduce the high frequencies, while adding a slight boost to the low-end, which creates “warmth”.

This is often confused with saturation, because it’s such a characteristic sound, however, this only emulates a poorly-calibrated tape machine.

Tape machines that are calibrated properly do not attenuate the high end, but we all assume tape sounds like that, so that’s why plugin designers do this.

You can use Tape Saturation plugins for adding this warmth, as well as generating nice, subtle harmonic content.

We love tape saturation on Pads, Synths, EP’s and Pianos, and other harmonically rich instruments.

Another great use for tape saturation is using it in the mastering process, to add that warmth a track might need. If you make indie rock, or any other similar rock genres, tape saturation on the master bus, is as close to a rule as you can get in music.

Tube Saturation

tube saturation plugin

Arguably the most popular type of saturation, tube saturation evokes an instantly recognizable warmth in your recordings.

Tube saturation is also a by-product of overload.

Saturation will happen when electrons can’t flow from the cathode to the anode of a tube, due to a positive electrical charge. This electrical charge appears, when you’re overloading the tubes with strong enough signal.

This overwhelms the tube, which means it can’t sustain a linear input to output ratio, essentially, compressing the signal.

Tube saturation produces something called “second-order harmonics”.

This is essentially a boost to the second harmonic of your signal.

In music, the second harmonic is an octave above the fundamental frequency. This harmonic is nearly inaudible, but it adds a nice body to the sound, producing a fuller and warmer sound.

Similarly to Tape Saturation, tubes also make your signal sound “warmer”. Whereas with Tape, warmth comes from high frequency attenuation (reduction), tubes produce warmth from boosting the low mids (2nd harmonic).

While on paper their utilization may be the same, the difference in sound and warmth of tape vs tube saturation, is clear as day.

Tube saturation tends to be more subtle, than tape saturation.

You can almost always tell, when something has been tape saturated. Not always can you so easily distinguish tube saturation however.

Most guitarists are already very well acquainted with the concept of tube saturation, but in the electronic music world, tape still reigns supreme.

This is mostly due to the incredible popularity of lo-fi genres and the overall resurgence of the “analog” sound.

For us however, tube saturation adds so much, but in such a subtle way, that not using it on every project feels like a sin. Pushing your tube saturators further can produce a very round and pleasant distortion, and for music that’s not squeaky clean, tube saturation is the greatest.

Transistor Saturation

In terms of hardware, transistor saturation is the single most common type of saturation.

Most music hardware consists mostly of transformers and transistors. Essentially, unless you’re working with other components like tubes, you’re working with transistors.

You can imagine the transistor as a sponge.

It takes in electricity and squeezes it out at the same time.

With enough signal, the sponge can no longer absorb as much as it squeezes out. Everything that spills over essentially bypasses the transistor.

Photo by Anna Shvets from Pexels

This spill over as we’ll call it, is what produces your saturation.

The sound of transistors overloading adds harmonic distortion, as well as a kind of “hard clipping” compression.

Gritty, textured and compressed, the sound of transistors overloading is what most associate with clipping. Pushing transistor saturation too hard will absolutely destroy your transients, reduce dynamics and distort. Subtler settings produce overall smoother distortion and tone.

You’ll hear transistor saturation in most of your guitar pedals, outboard gear, as well as a lot of VST plugin emulations, which purposefully emulate this sound.

The most famous brands to use transistors is Neve.

Most of Neve’s components have a certain transistor crunch, which has been extremely sought after by the engineers of the world.

Our favourite Saturation plugin, the Soundtoys Decapitator incorporates a separate mode that emulates this exact Neve transistor sound.

In fact, Decapitator offers tape and tube saturation models as well, which is why we really love the versatility and power of Decapitator.

How To Use Saturation

Saturation at it’s core is a really powerful effect. It can be used subtly during recording, to introduce depth and texture to your audio, or, slammed hard to smash your drums and create aggressive, distorted sounds.

On top of that, the different types of saturation are good for a set of different uses. Let’s run through a couple of our favorite uses for Saturation.

Drum Glue

So, the biggest issue with most beginners’ drum buses is that all elements sound too separate. This might be the way to go for crispy clean EDM, but for most other use cases, we want our drums to work as a cohesive unit.

If you’re listening to a drummer play, you’re not hearing only the cymbal there, and only the snare there, all of the drum sounds mix together in space. If we’re making electronic music and sampling however, we have to achieve it manually.

For this, we can use saturation. Apply tape saturation to your drum bus, to tame any harsh transients as well as add harmonic material and soften the high end.

The added character and excitement, over the entire bus, helps to glue the drums together. This makes them feel like a set of drums, rather than separate percussion sounds in space

Parallel Saturation

Just like compression, applying saturation in parallel is also very fun.

Say you’re experimenting with a saturator on some synths or guitar. You like the effects produced with more harmonic distortion and texture at higher levels of saturation, but want to preserve the original sound as well.

At these higher settings, your original signal becomes very different, and loses clarity. Again, this might be what you’re going for, but in our example, we’re aiming for a more clear, but textured sound.

Try running your saturator on a send, and sending your synths or guitars to it. This will mean you can easily mix between the dry and wet signal, with the gain of your saturator. You preserve the integrity of your original audio, and only add saturation on top.

TIP: When doing anything in parallel, make sure to have your dry/wet on 100%, otherwise you’ll be adding the original recording as feedback, which will throw your gain staging off.

Tube Saturation for Bass

Low end instruments, subs, basses etc. can all benefit from saturation. Our favourite type of saturation to use for bass is tube saturation.

Just like a tube amp, tube saturation will add energy and help make your basslines fatter. Harmonic distortion on bass also helps to refine it’s mid-range. This helps your bass cut through the mix better.

Additionally, the second order harmonics add a clear warmth and thickness to your bottom end.

Using tube saturation in parallel for bass is what we usually do with out basses. Adding on the pleasant tube amp distortion to our original signal retains clarity in our bass, while adding a layer of texture and distortion.

Alternatively, use transistor saturation for more digital sounding clipping artifacts and sharper harmonics.

Tape Master

Using tape saturation plugins on your master bus can create a more cohesive sounding mix. However, this has to be done in a subtle way, not to dull your mix. Add too much saturation while mastering and your mix will start to lose it’s high end presence and clarity.

Using tape emulations to saturate during mastering is awesome, but another great thing that people like to do is using a console emulation. A console emulation plugin simulates your master being run through an analog console.

Using channel strips and preamps on individual buses and instruments can serve to solidify the analog sound and add a bit of warm character to your overall production master.

How Much Saturation Should I Be Using?

Saturation is extremely versatile.

How much you use on a channel will be entirely dependent on what you’re trying to achieve. Separating the production processes of sound design and mixing is important to form your own opinion on this.

Often however, when talking about sound design, we’ll saturate our recording more, than during mixing. When designing your sound, anything goes, let’s say you’re working with vocals, you could try to warm them up, or go for extreme digital compression.

The amount of saturation you’ll be using is based solely on the effect you’re trying to achieve.

Mixing however means processing your music, to maximize clarity and create cohesive sounding music, through compression, EQ etc. Aside from running a saturator in parallel, for mixing purposes, the amount of saturation will be minimal.

In this case, we want the listener to feel the saturation more than they’re hearing it.

It’s a way to create a more analog sounding mix, without affecting the overall clarity and quality of the audio.

This is why, during mixing, we’ll usually try to stick to small amounts of saturation. Your production style may differ however, so don’t let us hold you back from adding exorbitant amounts of compression and character to your drums.

Sometimes a really warm mix with tons of distortion and digital clipping is exactly what you need.

Finishing Up

Saturation is a very subtle form of distortion usually used to bring presence, “warmth” and analog harmonics to your audio. Saturation comes from the old days of analog hardware, with your signal running through different pieces of hardware.

That leads us to the end of our guide on how to use saturation. Whether you’re looking for 2nd order harmonics, an analog distortion effect, or you just want your mixes to sound a bit more analog, saturation will help.

Saturation is an extremely powerful and versatile effect, to apply on vocals, synth plugins, your entire mix, or anything else you want to give some depth to.

After reading this, we hope you’ll feel more comfortable to use saturation in your next music production, mixing or mastering session.