While they’re both essential deliverables for many working audio engineers, stems and multi-tracks are not the same thing and the terms should not be used interchangeably. There’s a big disconnect though, and it happens at all levels of the music industry.
People ask for stems when they really mean multi-tracks. Others might ask for the session as a whole, or the “raw” files. Often I find myself clarifying exactly what I need to make sure I can do my job and getting the same clarification from others to make sure there’s no gray area.
While it’s probably not the most glamorous part of the recording process, knowing the correct terminology and where/when it’s appropriate to use these terms can make you an in-demand individual to those that value working with people who understand what they’re doing in the pro audio realm.
Multi-tracks are exactly what their name implies – multiple tracks from the recording session. The terminology has been used in studios for decades; as far back as multi-track tape recorders existed. Engineers have continued to use this terminology in the digital world today.
The hand-off from recording engineer to mixer should always include multi-tracks of the session. If there’s an editor doing cleanup between the two, they should be receiving the “raw” multi-tracks from the recording engineer and providing cleaned and comped multi-tracks to the mixer when they’re done.
A mixer needs the multi-tracks to do their job correctly. Providing them anything less means fewer options when mixing and less control they have when balancing the mix.
Usually, multi-tracks will not include much processing other than what exists in the recording signal chain. This would traditionally mean any EQ or compression on the way in would be fine, but with more and more engineers using low-latency monitoring and in-the-box processors, it may include some plugins that have been printed to the track as well.
Time-based effects should not be printed to the source audio track, but may be helpful for reference if they’re printed to their own. A great example of this would be a singer’s reverb during recording. Your mixer will likely want to have the control and option to use reverb and delay as they see fit, but giving them a reference of what was used in tracking can give them insight into what the recording engineer envisioned for the voice.
Stems are stereo tracks printed down at the end of a mix that should sound nearly identical to the final mix when played back at unity gain (0 dB on all faders). The only difference would be mix bus processing, as it isn’t usually applied to the stems. They’re usually printed in stereo groups, which can vary from session to session. The most common stems include: Drums, Guitars, Vocals, Bass & Synths/Production Sounds. A good rule of thumb is to print anything that’s got bus compression gluing the group together.
The idea of a stem is to give remixers flexibility to use parts of the mix in their final form, but with the isolation that comes from having separate tracks. For this reason, many mixers prefer to print their effects directly to the stems as well – keeping their vocals, guitars, etc. sounding exactly as intended.
Stems can also be used to create alternate mixes quickly and easily. If a band you’re working with gets a song licensed for a car commercial and need the instrumental version, they don’t need you to go back to your original mix session to get it. Instead, your stems can be loaded into any DAW and printed with the vocals muted. The same goes for other common mix requests: vocals up, vocals down, production only (backing tracks), a capellas, and more.
Think of all the time you can save by not having to create all of these mix variations yourself!
You Own The Session
Bear in mind that regardless of your role in a song, you’re not required to hand over a full session to anyone unless it’s been agreed upon in a contract. The session itself is your work, just like the master tapes of older analog recordings. The band or label is usually paying you for the audio – the multi-tracks or printed stems within the session. The secret sauce behind it that you’re applying in the DAW is completely yours.
If you’re ever concerned about whether or not you need to give someone the session as part of a contract, please consult a lawyer to make sure you’re protecting your interests.
Developing Your Secret Sauce
Over time, every producer and engineer develops their own workflow and plugin preferences for various parts of a session. It’s what makes their sound unique. Whether those preferences are made to imprint their stamp of approval on a mix or are made to keep them sounding as transparent as possible is up to each of them.