9 March 2026 | 5 min read
Mono vs stereo recording: why dialogue stays mono
One microphone, one channel. The rule is simple, and the exceptions are where the interesting work happens.
New location recordists often assume stereo is a quality upgrade. It is not a quality setting, it is a spatial one, and using it in the wrong place makes dialogue harder to edit rather than better.
Dialogue is mono, always
A boom is one microphone. A lav is one microphone. Each produces one channel of audio, and that channel should be recorded and delivered as mono. A dialogue editor needs to place voices in the mix deliberately, usually centre, and a mono source gives them full control.
Recording a single microphone as a dual mono stereo file wastes space and creates confusion downstream, where somebody has to work out whether the two identical channels are meaningful.
Where stereo belongs
- Atmospheres and ambiences, which need width to sit under a scene.
- Live music and performance capture.
- Crowd, traffic and location wild tracks intended to place the audience somewhere.
- Sound effects recorded for a library, where spatial information adds value.
The phase trap
Combining two microphones on the same source, for example boom and lav, is not stereo. They are two mono perspectives of one sound arriving at slightly different times. Summed carelessly, they comb filter and the voice goes thin and hollow.
Keep them on separate mono tracks, let the editor choose one per line or align them deliberately, and never pre-mix them into a stereo pair on set.
Delivering mixed material
A typical shoot day produces mono dialogue stems, a stereo mix track from the recorder, and possibly stereo ambiences. Post wants those clearly separated and clearly named.
If your recorder writes everything as one poly file, split it so the mono tracks arrive as mono and the mix pair arrives as a proper stereo pair. Our channel mapper handles exactly that: pick which channels become mono files, which pair becomes stereo, and rename everything before export.
When you need to go the other way
Sometimes you receive separate mono files that belong together as one interleaved deliverable. Merging mono tracks back into a single multichannel WAV, with per track gain and names, is the mirror image of splitting, and just as common in a delivery pipeline.