Many production music libraries – especially exclusives – will ask you to provide Stems of your tracks.
What is a Stem?
Stems (‘stereo masters’, also referred to as sub-mixes, subgroups, or bus exports) are a collection of tracks in the same instrument family grouped together for processing, before they reach the main output in your DAW.
For example, for an orchestral track you could provide the following stems in addition to the main track and edits:
Why do Production Libraries need Stems?
Video editors like to work with stems as they allow them much finer control over the music mix in their project.
They can add and remove elements at will, such as deciding to mix the percussion lower, or remove the strings section completely.
There are no hard and fast rules around which stems to provide, and some libraries will let you know their requirements once they’ve heard the original track.
Configuring your Project to use Stems
To begin with, create bus/groups for every stem you’ll need. Using the example above, they would be; Choirs, Winds, Brass, Strings and Percussion.
Instruments within a particular instrument section are then routed to the appropriate group/bus:
- Trumpets, Horns, Trombones and Tubas > Brass Stem
- Violins 1, Violins 2, Violas, Celli, Bass > Strings Stem
You probably already use a this method to mix instruments in the same family together – such as using a group/bus track to apply compression to your drum tracks or to apply the same reverb to a brass section.
Taking it further, if you’ve written a hybrid orchestral track, you may find you also need to include the following additional stems:
- Synth Pads
- Synth Bass
- Hybrid Percussion High
- Hybrid Percussion Low
Differences in the Mixing Workflow
Mixing a track that includes stems involves a different workflow.
Instead of applying mastering plugins to the main output, you need to mix each stem individually as well as making sure the track still sounds cohesive when all stems are played together.
So you will need to apply your usual master processing plugins, such as EQ, limiters and compressors, to each stem, rather than to the master output.
Dealing with Send FX
If you use sends for reverb or other effects, you also need to make sure each stem has its own individual FX track/bus so that all effects are included when exported.
DAW’s handle the exporting of stems in different ways, but I strongly recommend setting up a master template with all of your stem routing already set up.