Hey there! I wanted to talk a bit about Stem Mixing; a method of mixing I use in practically every mix!
Stem Mixing (or sub-mixing) is the process of grouping audio tracks and setting the output to auxiliary tracks called ‘stems‘. Eg sending all the drum tracks to a ‘drums’ auxiliary, sending all the vocal tracks to a ‘vocals’ auxilary track, and so on! This enables greater control over levels of each instrument, being able to quickly and easily change the levels of, say, all the guitar tracks at once. Going even further, you can group different instruments together as aspects of the track, like Dave Pensado’s method:
- All Drums
- Music (Keyboards and Guitars)
- All Vocals
- All Effects
- Hi-End (Cymbals)
In this video, Dave shows how stems can give you greater control over different aspects of the track. Changing the levels of these aspects can greatly affect the overall feel of the track. Here’s some examples:
- Too much Bass can make the kick sound weaker, and give the track a more ‘urban‘ sound, whereas too little can leave it sounding empty.
- Too little guitars can leave the voice and drums exposed, and make the track lose it’s power – sounding more ‘pop’ than ‘raw’, whereas too much can over-power the vocals and leave them sounding weak.
- Too little high-end can leave the track sounding dull, whereas too much can over-power the brightness of other instruments and get too ‘washy‘.
It is important to realise, however, every genre suits a different mix of levels. Hip-hop and urban music suits more low end, rock suits more guitars, acoustic suits lots of vocals. Remember though! There is no right and wrong! Everything is subjective, and every mix is different!
Pro tip: When mixing, use other tracks in the same genre or style as the one you are working on as a reference. It is easy to get lost in your mix and lose perspective!
I find stem mixing makes the mixing process much easier, especially in the latter stages of mixing where you’re trying to polish everything off having got individual tracks sounding and interacting how you want them. It also helps in mixes with a large number of tracks, breaking the mix down into more manageable chunks!
Here’s an example of how I have broken a track down:
This mix had 38 audio tracks, which was almost un-workable in terms of mixing everything one by one. After getting each individual track sounding good (EQ, comp, etc) and interacting how I wanted them, I grouped them into categories to simplify the mix into a more manageable chunk. From there, I could add plug-ins to the stems and effect multiple tracks at once.
Every engineer would have done this differently! I chose to break things down this far and no more because I still wanted control over some details like the cello solo and double bass levels. Always organise a mix so you are comfortable with it, not just because some blog told you to do it some way! You are likely to get better results when you are happy!
Another use of stem mixing is in world of video games, as seen in the Amon Tobin ‘Infamous’ soundtrack. In this video, the audio is broken down into stem form and then organised into low, medium, and high intensity elements. These elements are brought in and faded out during game play depending on where the player is, and what he is doing at any specific time. During calmer periods, only low intensity elements would be present. As something is encountered by the player, medium intensity elements would be faded in. Finally, at high octane moments of gameplay, the intense elements would be brought in to heighten the players sense of involvement during intense periods. This adds excitement to fights and chases, while adding atmosphere and anticipation to less dynamic periods in the game.
This is a really cool way of thinking about stems. They don’t just need to group all the drums, or all the music; they can group any category of tracks together for ease of mixing!