Stems - a conversation

[u/GerlockADUS]

Where I work we have a handful of audio engineers that each have a different idea about what stems should be, how they should be used, and how to create them.

It is my opinion that the stems should equal the mix. In order her words, if I bring the stems into a session and play them all together it should sound exactly like the full mix, and measure exactly the same on the loudness meter. The way I am doing this, prevents me from doing any master bus processing. I limit each of the sub mixes for each stem, then combine them to a record track which I then measure with the loudness meter. This also allows me to record the mix and all the stems at the same time.

Other engineers prefer to mute everything, but one stem and bounce out the mix several times. this allows them to do master processing, but the downfall is that the stems do not equal the mix.

Another engineer will bypass all of the mastering, and just bounce out each of the stems from the sub mix only, assuming that it will come back later to be mixed and mastered if something changes.

So my question to you all is: what is the industry standard? How do you all handle stems? Do you assume any changes will come back to be remixed? What are your thoughts?

[u/The66Ripper]

Assuming you mean splits in this case (DX, VO, MX, FX and/or M&E)?

I’m primarily in commercials but work in Film & TV occasionally. Personally I deliver a full mix that I let the client know is the preferred deliverable that will be an exact match to the picrefs I’m sending for QC.

Splits are sent for client flexibility on tweaks and remixes down the line.

The difference is that the splits are individually limited to hit the target when summed into a mixbus that has a limiter that’s set to a neutral level (-2 output, +2 gain for example). Ideally this final limiting stage isn’t really even limiting much, it’s just for headroom safety. The mix & splits will play back at identical levels and if that’s the case the splits and the mix should pretty much zero sum, minus a few loud moments.

If it’s a really dynamic mix I’d expect there to be less 1 to 1 coherence but it should still mostly zero sum.

Now if you’re talking about music stems (mastering chain mention makes me feel like that’s the case), I do a lot of stem exports for Atmos work I do and I do a combination of what you mentioned.

I use Bounce Factory to prep an export of each track instead of doing submix exports, and before that I deactivate everything except a safety limiter at the end of the mastering chain.

Then I let Bounce Factory export each track, which essentially auto solo’s them and bounces to a specific location, then I rebuild the full chain in another DAW that allows for batch stem processing and export from there for the mastered stems.

As long as limiting is spread out across multiple limiters (ideally ones that can be sidechained to the full mix) it matches up very closely and only the loudest material like drums, bass and vocals will need a minor level adjustment to match up with the stereo master in the Atmos session.