Stem
A grouped submix bounced as its own file: dialogue on one, music on another, effects on a third.
See it
What it is
A stem is a group of tracks bounced together as one file: not a single channel, not the finished mix, but a layer of it. The film and TV standard set is D/M/E: dialogue, music, effects. Music people use the word for drums, bass, vocals, and everything else. Same idea, different grouping.
You need them the moment somebody else has to touch the audio. Localization swaps the dialogue stem for a dubbed language and keeps music and effects untouched. A trailer editor wants the music alone. A client wants the voiceover pulled up 2 dB without re-opening your session. Handing over stems means none of that comes back to you as a full remix.
Gotcha: stems sum back to the approved pre-master mix, not to the mastered one. Same start timecode, same length, same sample rate and bit depth, printed from the same session state with the master chain off. That is not fussiness: a limiter or glue compressor on the master bus is nonlinear, so it cannot be split three ways and re-added. Three separately limited stems will never total the master you signed off on. Deliver the mastered full mix alongside the stems, and if a spec demands printmaster split stems, follow that spec and write down which bus processing they share. Separate issue, same word: AI 'stem separation' tools pull approximate stems out of a finished mix, which is a rescue move, not a substitute for printing them properly.
Ask AI for it
Export this project as deliverable D/M/E stems: one dialogue stem, one music stem, one effects stem, all starting at the same timecode, identical length, 48 kHz 24-bit WAV, printed pre-master with no limiter or loudness processing on the individual stems. Verify that the three sum to the approved **pre-master** mix, not to the mastered one. Deliver the separately mastered full mix alongside them, plus a dialogue-free M and E version. Name them [project]_[DIA|MUS|FX]_v[n].wav. If the delivery spec calls for printmaster split stems instead, follow that spec and document which bus processing the stems share.