It’s one of the most mysterious aspects of the music production process – so what is mastering?
When producing a record, there are often several stages to the process. Firstly, there’s the ‘demo’ stage, where songs or tracks are sketched out, arranged and recorded to a high, but not ‘highest’ quality.
Next, there is recording stage. Here, all of the component parts will be recorded as audio to the highest quality possible. From here, the engineer and producer, will mix it, taking all of the individual elements, and adjusting levels, EQ, FX and more to create a sense of dynamics, momentum, and artistic vision that befits the track.
Finally, the track (or album) is sent for mastering. This process, however, is somewhat shrouded in mystery.
Exactly what is mastering?
From ‘pretty good’ to commercial release…
Put very simply, mastering is the final, post-production process that takes a mixed track from sounding fairly good, to (hopefully) sounding like a killer, polished commercial track.
It can be used to fix any errant issues with recordings (though as always, it’s better to make sure that the mix is perfect to begin with…), and is often used to create a sense of uniformity, and coherence within an album or EP. So, the mastering engineer will ensure that track levels don’t jump, or drop in a jarring way, from one track to the next (unless that is the intention, of course)
Mastering engineers are hugely in-demand, however, so clearly, they’re doing more than adjusting levels…
Getting the best out of a mix
The ultimate aim of a mastering engineer, when working of a finished mix, is to make it sound as good as it possibly can, in the most transparent way possible. Unlike mixing, where you may want to give a track a particular sonic character or style, when mastering, the techniques applied should natural sounding, and fairly unnoticeable.
Common techniques include compression, EQ, stereo widening, arranging albums with fades, gaps, track markers and info, and preparing tracks for particular mediums.
Compression can be applied for several reasons. From a ‘quality’ perspective, it is often applied as a sort of sonic ‘glue’. When a mix is finished, the various parts can sound a bit, well, separated sometimes. Judicious use of compression can tie these parts together.
Secondly, compression can sometimes be used to fix any problem frequencies within a track. A multi-band compressor can be used to find these bands, and compress them individually.
Loudness (sadly) is also a factor in mastering, too, for which compression and limiting are the main tools. Essentially, record labels need their tracks to sound similar to other tracks within the appropriate genre. This includes perceived loudness- if your track is played on the radio, you don’t want it to be quieter than the tracks around it.
Striving for tracks to be ever louder has led to more and more compression and limiting, often to the detriment of the track. But, we won’t get drawn into the ‘loudness wars’ here…
Compression will also be used to maintain a consistency of perceived loudness throughout an album.
Finally, due to the differing limitations of the various recording mediums, compression will be used to ensure that the track will remain within the limits of the format’s dynamic range.
There are unique features of all mediums, meaning that masters often have to be produced in slightly different ways for different formats. For example, when mastering for vinyl, it must be ensured that low bass frequencies are mono, not stereo, as stereo bass frequencies can cause the stylus to skip when playing back.
More recently, ‘codec’ plug-ins have appeared, which mimic the effect of compressing to the various lossy formats (MP3, AAC etc.).
EQ is also used to achieve consistency across the course of an album or EP, and to fix minor frequency issues (though by this stage, EQ adjustments should be very minor)
This is the briefest of overviews to answer the question ‘what is mastering?’ It is a huge subject, however. There are reasons that artists are happy to pay sizeable sums to have a top mastering engineer put the finishing touches to their work, as it takes incredible hearing and huge amounts of experience to do well.
Most of the big DAW packages now come complete with suite of effects specifically for mastering (Sonar, Reason, Ableton…) With some patience and practice, you can achieve some excellent results at home, too.