What Is Mixing? The Anatomy Of A Mix
Mixing seems to mean different things to different people. We asked Grammy wining mixer, and founder of The Mix Consultancy, Dom Morley, to unpack the subject of mixing and explain the anatomy of a mix.
What Is Mixing?
Although we can define mixing as simply “combining recorded sound from a multi-track recording into a single audio file (be it mono, stereo or surround)”, the act of “combining” in a way that actually sounds good to us can be pretty complicated.
To make it simpler, let’s break down the art of mixing into four basic processes – balance, EQ, compression, and effects. An overview of these should give us a better understanding of what mixing actually is, and like all aspects of sound engineering, they are best approached from both a technical and creative standpoint. You’ll see what I mean…
Balance
This is the foundation upon which all mixing is built and is simply setting the volume of every instrument in your track. It starts with a static balance – all the faders on the mixer are at a level that you are happy with and you can pretty much hear everything as you play through the track. This is your technical job done as you’ve established a decent balance. However, your mix is nowhere near finished! Now we get into the creative part of mixing, which is where a good mix becomes a great one.
Automating the faders is how you make your mix come alive. As a mixer, you should be getting a feel for the dynamic of the track – how it ebbs and flows, where the natural quiet and loud sections are. Your job is to accentuate that natural dynamic and make sure the listener really feels it at every step. You should also be directing the listener’s attention – via your subtle (or not so subtle) volume changes – to the specific elements of the mix that you think they should be listening to at every second - every beat - of the track. This requires quite a lot of movement as you are building a constantly shifting, fluid balance. It’s also worth pointing out that this process often means that your mix will sound worse before it sounds better. As you move the volume of a few elements around, you lose the static balance that you started with, and that needs to be re-gained and improved upon for the particular part of the song that you’re in. To give an example of the importance of this, when I was an assistant engineer in a big studio complex, we would often have big-name mix engineers work there. When this happened, all of us assistants would sneak into their studio after they had gone home to find out what they were doing and if they had any tricks up their sleeve that we didn’t know. They never had. But if you played back their mixes you did notice one thing – the motor-driven moving faders on the desk were all moving, all the time. The detail of volume automation was the only thing that I could see that set these guys apart. Obviously, they had good enough ears to hear where the moves were required, but they were subtly shifting all the elements around all the time so that the balance was exactly as the mixer wanted for every second of the track.
That’s what turns a good mix into a great one.
EQ
This is short for ‘equalisation’, which gives you a clue to it’s use. EQ allows you to reduce or increase the volume of frequencies within a sound. So, if you have an instrument that is too prominent in a particular frequency, you can use your EQ to reduce this frequency and ‘equalise’ it against the rest of the instrument. This control allows you to really sculpt the sounds within your mix, as well as the mix itself. The great sculptor Michelangelo was once asked how he managed to turn a formless block of marble into the masterpiece that is his statue ‘David’. His reply (or so the story goes) was that it was easy - all he had to do was chip off everything that wasn’t David (I know – ask a stupid question, get a stupid answer). That said, this is what we are trying to do when we EQ a sound – we filter off and reduce those frequencies that we don’t want, and boost those that we do. This allows us to do two things. The creative side of EQ is what you probably do already – making things sound better. Whether you are simply brightening up some cymbals or adding 50Hz to make your kick drum thump, or drastically re-shaping a vocal so it sounds like you are singing through a megaphone, creative use of EQ is probably something you’ve been doing since you first started recording music.
The technical aspect of EQ is where good mixes come together. It is the structuring of layers across the frequency spectrum. Whenever you bring a new element into your mix, listen out for any frequency that suddenly feels like it’s a bit clogged and muddy. This is an area that is prominent in your new element, and also in something that is already in your mix. You use EQ to make space in one or more of those elements to allow the new sound to sit comfortably. Do that for every instrument and you will have clarity and space in your mix.
Compression
Compression (and it’s more extreme cousin, limiting) is used to control dynamics. This can be across a whole track, or within an individual note. Again, we can define these as technical or creative. The technical application of compressors is the thing that they were originally designed to do – turn down the loud bits and turn up the quiet bits. To that end, early compressors had two controls – peak reduction (turn down the loud bits) and gain (turn up the quiet bits). If you stick a compressor over a particularly dynamic instrument then it will be more compressed when it’s loud (and so it’s loudness is reduced) and the compressor won’t be doing much, if anything, when the instrument is quiet. But (I hope you’re thinking) isn’t that ‘levelling out’ what we do with our volume automation? Well yes, it is, but in the grand arc of recorded music, volume automation arrived fairly late - the first compressors were invented in the 1930’s, while automated faders didn’t arrive on mixing desks until the mid 1970’s. Even then it was pretty basic, so compression was still important for controlling levels. Fast-forward to today and you can automate literally every parameter of the mix in your DAW, so you can really concentrate on using your compressors for their more creative function, and that’s shaping the dynamic (sometimes called the envelope) of individual sounds. Modern compressors give you control over attack time, release time, threshold, ratio – everything you need to squeeze punch and power out of previously flat and ordinary sounds. This is where compression, and mixing, starts to sound really exciting.
Effects
Sometimes abbreviated to ‘FX’ this is an umbrella term for a whole host of different things - reverbs and delays, chorus and phasers, saturation and distortion (and so on). Although often seen as the really creative tools that a mixer has at his or her disposal, they do have a technical function as well. With no reverb or delay (‘delay’ is also known as ‘echo’) a mix will sound two dimensional and flat. A mixer thinks about placement of the instruments not only in terms of the stereo field (I’ll assume mixing in stereo here as that’s what most of us are doing) but also in the depth of the sound stage. Using reverb or delay to move elements far away from, or close to, the listener’s ear is a powerful tool (in combination with panning) to give space and clarity to a mix.
But let’s not forget the creative aspect. There are the obvious effects like making something sound noisy with distortion, or warm with a wide chorus, but you can use effects to manipulate emotions too. A dry vocal will sound more intimate and grab the listener’s attention, and a reverbed-soaked voice in an empty mix can sound lost and alone. Effects are like lighting on a film set – they can be subtle or bold, warm or harsh, and anywhere in between, and as with all the tools we’ve discussed so far, they are used to get the best out of the recorded material
Now we have a clearer idea of what mixing is, let’s quickly talk about what mixing isn’t. Sometimes there’s confusion here, but hopefully this will clear it up.
Comping
This is the compiling of master takes from all the recordings that have been done. For example, in the recording session the singer might have recorded the lead vocal ten times. All those takes need to be compiled (‘comped’ for short) into one master take which features all the best bits of those 10 performances. Choosing the best parts for a comp is one of the most important roles of a producer as it can completely change the feel of the song. If the track in question is being mixed by someone other than the producer, then those decisions should definitely not be left to the mixer. And if the producer and mixer is the same person, then separating the tasks of mixing and comping (both of which require a huge amount of concentration to do well) will allow the right amount of focus on each job.
Tuning
The tuning of vocals is a feature of modern production, whether it’s something you are a fan of or not. But the fact is, it’s a feature of production and not mixing. Just like comping, it’s something that can greatly affect the feel of the track and so the producer should be the one to call the shots on this one – and have it all done before the mixing process begins.
Want to check out some tuning software, here’s some of the most popular;
Mastering
This is a separate process that happens after mixing and is much better done by someone other than the mixer. I won’t get into what mastering entails here as there is a whole other article that does exactly that, but despite the fact that mixing and mastering can sometimes be mentioned in the same breath, they should definitely be treated as separate and distinct processes.
If you want to find out more about mastering, then visit our mastering tips and tricks section.
Summary
As you can see, although you can just combine all the instruments in your DAW and the resulting mono, stereo or surround file will be (technically speaking) a mix, this probably won’t result in something that you actually want to listen to. Careful and creative use of the techniques above is how you turn a collection of sounds into a finished track.
Photo by cottonbro