This post was originally published on Resoundsound.
Saturation is a wonderful tool for mixing. This is especially true for computer-based DAWs, which allow us to go from transparent clean digital sound through to smeared murky smashed sound. And everywhere in between. The variety of available plugins and different approaches give producers and engineers a huge toolkit and capability to choose the right saturation for each track.
I use saturation in a variety of ways in each mix. While each sound and each mix is different, my approach to saturation usually falls into one of three broad groups: Invisible saturation, noticeable saturation, and overdrive.
This is the least noticeable. I wouldn’t even call it ‘colour’. When I use this approach, my goal is for the saturation to be unnoticeable for casual listening. I wouldn’t even call it subtle – it’s less than subtle. The saturated audio should still sound clean.
So what’s the point? I use this approach when I’m pretty happy with the sound of a track, but it’s just sounding a bit digital/boring. So I add some saturation just to inject a bit of energy and vibe. I often use this approach for tracks – such as lead vocals – that need a bit of vibe while still sounding clean.
If you want to take this approach, you’ll need to listen carefully to what your tools do before they start to break up the audio. Less sophisticated tools will be too transparent until they start to break up. More sophisticated tools will subtly adjust the dynamic behaviour or crest factor of the audio. They might also change the tone a little. Each tool is different. Many dedicated saturation plugins have a variety of modes, with different behaviour for each mode.
This is where saturation starts to be noticeable. When I take this approach, the character of the sound is definitely changed. I’d still call it subtle, though, because sound is still recognisable and maintains the same role in the mix. I just give it a bit of hair.
This is an approach I usually take when I need to give an instrument a lot more energy and punch. Typically, I use this approach for synths and drums that aren’t strong enough. Sometimes bass too, depending on the mix.
If you want to take this approach, you’ll need to pay close attention to the tonal change your tools are introducing. Less sophisticated tools will just add a harsh crunch or fizz to the sound (which might be heat you need). More sophisticated tools will sound alive while still retaining a lot of the the clarity and character of the sound. Be careful though – it’s easy to add too much. What might sound good in solo will sometimes turn to mush in the mix. A little bit goes a long way.
This is where things start to get irresponsible. While the level of saturation here wouldn’t be as much as what guitarists would call overdrive, this saturation is quite noticeable. It sounds like an effect.
I only use this approach rarely – and when I do it’s only once or twice in a mix. Most commonly, I use it as a spot effect on vocals, and sometimes on guitars to blur the line between an acoustic and an electric. Percussion can sometimes take well to overdrive, but it’s highly dependent on the source sound and the saturation tool. Membrane percussion (such as tablas, bongos and djembes) can have their decay emphasised and can end up sounding very tonal. Bright percussion (such as shakers and tambourines) can sound very trashy when pushed too hard.
If you want to take this approach, you’ll need to think carefully about what part of the song (not just the mix!) would benefit from this kind of emphasis. Treat it as a special effect.
Reading this, it might sound obvious. But – like any other mix tool – it’s useful to approach saturation in a rational and deliberate way. That way you can be more focused and productive in your mixing and avoid blindly trying different tools and approaches to see if they work.