Stem mastering – what, how, why?

By | April 4, 2021

Common to almost all types of mastering, however, is the focus on frequency balance, ie the music should sound as good as possible in as many different sound systems as possible – without losing the sense of origin. One of many methods is called stem mastering, which means a slightly different way of mastering.

Mastery passes usually of more parts than just focusing on the sound, such as song order, insertions and sweeps, volume adjustment, overall feel, adaptation to streaming services, distribution and so on – something that today’s article does not go into.

A classic example of what stem mastering can look like, where all channels are treated individually if necessary, and then exported to a finished master.

Stem mastering (voice mastering) can be seen as a kind of a mixture between mix and master and in short means that the master works with instrument groups instead of a single stereo track.

A stem mastering can look like this:

  1. Drums

  2. Base

  3. Guitars

  4. Keyboard and strings

  5. Singing

When these files are played together, the remixes should be the final mix exactly as it is meant to sound. These channels / stems are treated individually like a regular mixing session, and then culminate in a finished stereo master. The advantage of mastering stems, instead of a single stereo track, is that it is easier to influence individual instruments both in terms of volume and frequency, instead of wrestling with the entire soundscape at once. Most important electrical elements in the mix are thus available separately, albeit to a lesser extent than traditional mixing.

A classic example is a mix with too much or too little bass or with problematic singing. If you work with a stereo file, ie the traditional way of mastering, the whole mix is ​​affected if you raise or lower, for example, 80 Hz. This does not have to be a disadvantage, but can mean that the bass suddenly becomes too strong, or that the song feels cloudy. We continue to play with the idea that this must be compensated by lowering 40-60 Hz and digging out 200-300 Hz, which in turn makes the guitars suddenly more prominent and before you know it you have painted yourself into a corner and knows neither out nor in. This is of course an example of horror, but a not too unusual one, especially if the mix is ​​drawn with problems from the beginning. Then it is better to go back to the mix stage, or if there is the opportunity to work with stems where you can individually play with both volume and equalizer.

Even in stem mastering, there is reason to treat the master channel where all the group tracks meet for a final joint refinement. Every little helps…

In the best of worlds, stem mastering would not exist. At the same time, mastering would not really be needed at all if everyone could mix “perfectly”. But that is not the reality and then it is lucky that there are alternatives. One danger with stem mastering is that the original vision and feeling can be lost, especially if it’s a band mixed together. Here it is important to have a clear dialogue regarding advantages and disadvantages before any decisions are made. There can definitely be a point in tuning your own music, not least to give the mix a new perspective, both visually and acoustically – something that is often directly necessary if you produce yourself.

When is it relevant to use stem mastering?

  • If the mixer does not have the opportunity to adjust the mix on his own according to the master’s technician’s wishes. This may be due to incorrect listening, lack of experience or hearing problems.

  • If the mixer hears the problem but does not have the right equipment to correct it. It can be about compressing the bass correctly or using the right amount and the right kind of de-esses on the song.

  • When the mixer prefers stem mastering because he wants the mastering technician to put his own stamp on the mix and improve it as far as possible.

Stem mastering means a world of possibilities, for better or worse. It gives the master more control and sometimes that is exactly what is needed, other times the problem is solved better in the mixing stage. It is a much more time consuming process than traditional mastering and costs were also sold thereafter. In the end, it is the music that decides. In any case, it is clear that stem mastering is an excellent alternative to regular mastering, regardless of whether you master yourself or hand over the job to someone else.

Good luck!

Feel free to ask questions or comment on the article in the comment field below, and we will spin the topic together. Or if you prefer to discuss mixing in the “Mixing and mastering” section of the Studios forum here!

Fredagstipset is a recurring series where Studio writer Jon Rinneby shares tips every Friday in, among other things, recording and mixing. Here you will find all Friday tips.