Saturation effects can be used in different ways to make mixing easier. Find out how...
Saturation can be one of the most helpful and versatile mixing tools available to you. Depending on how you employ it, it can leave you needing less EQ and compression, and sometimes it can even be used in their place. But it’s also very easy to overdo it! In this article, I’ll consider a few different ways in which you might take advantage of saturation to improve the quality of your mixes.
You can listen to audio examples on this page or download the ZIP file below and audition the 24-bit WAV files in your own DAW.
The term ‘saturation’ once specifically described the effect of overloading analogue circuitry or recording media — think valves, inductors, transformers, op‑amps, loudspeakers, magnetic tape and vinyl — by passing high enough signal levels through them that they were operating outside of the designer’s intended ‘linear’ range. Non‑linear behaviour can be incredibly complex, producing harmonic distortion, tonal change and dynamic effects that all vary considerably with level. This is why when you hear a mix engineer use the term ‘saturation’, they usually also offer at least one enticing but slightly vague description of the quality it brings to an audio signal: warmth, glue, grit, vibe, cohesion, girth… you get the idea!
Today, we have access to an almost bewildering range of hardware and software gizmos that either emulate this aspect of specific analogue processors and media, or are designed from scratch to deliver an appealing saturation‑like complexity. Some equip the user with a huge degree of control, while others aim to deliver the perfect sound with only a knob or two. There isn’t really a ‘best’ tool to choose, or a ‘correct’ way in which to use it: the sort of character they can add to different sources is very much a matter of personal taste. But when choosing your tools, it’s worth considering just what it is that you want to achieve. With that in mind, let’s consider some helpful saturation strategies.
First, let’s look at how you can recreate in a software DAW the way saturation might come about when mixing on an analogue desk. Depending on an analogue desk’s architecture, a source might pass through several transformers, op‑amps or valves on its journey between the channel input and the speakers, and each can have an effect on the sound. On a vintage Neve or API desk, for example, an audio signal typically passes through several transformers and active gain stages, each of which adds a very subtle character. So too will any outboard processors or effects and, if you’re recording to it, analogue tape. This effect can be exaggerated by running the signals ‘hotter’ into any of the various stages. This is what people are referring to when they describe mixing ‘into’ a desk or making a desk ‘bend’.
Some software DAWs already have analogue emulation built in. For example, Pro Tools has its Dave Hill‑designed HEAT feature, Universal Audio’s LUNA offers Neve and API‑style summing, and Harrison’s MixBus 32C is designed to deliver some of the sound of their most famous console. But it’s fairly easy in any DAW to set up something similar using plug‑ins — and because there are so many suitable plug‑ins, this can give you a little more choice over the nature of the saturation character too.