At the end of every setup, before anything moves, record sixty seconds of the room with the same microphone in the same position and the same everything running, and slate it out loud.
Record room tone on set: the sixty-second routine
checked 2026-09-16rots yes — figures above moveresponsible Room Tone Register (a named register, not a person)
The routine
- Wait for the room to settle. Bodies moving, doors closing and the boom operator's feet are all part of the residual you are about to record.
- Say the slate out loud: scene, take, 'room tone', and the date. This is the only identification the file will carry.
- Record sixty seconds minimum, ideally ninety, with the same microphone, the same gain, the same position and the same equipment running as during the take.
- Do not talk, do not move, do not let anyone open a door. If someone does, stop and start again.
- Record a second pass with the air handling off if you can switch it off — that pair of takes is what makes the edit possible when the compressor cycles.
What must stay on
Everything that was on during the take. A room tone recorded with the noisy practical lamp switched off is not the room tone of the scene, and laying it under the dialogue creates an audible change in the residual at the seam — the exact artefact the tone exists to prevent.
The four things that ruin the take
| Ruin | Why it fails | Avoid by |
|---|---|---|
| Different gain | Residual does not match the take | Write the gain down; do not touch the dial |
| Different position | Residual has a different spectral balance | Leave the stand exactly where it was |
| Quiet room | Sounds like a drop-out when laid under dialogue | Keep the room as it was, including the fridge |
| Too short | Editor loops it and the loop becomes audible | Record ninety seconds, not twenty |
The residual does not need to be pleasant. It needs to match. A take with a refrigerator hum in it needs a room tone with the same refrigerator hum, or the cut will be obvious.
Source log
- 01Sound and the sonic environment, Sonic Studio Handbook (SFU)supports the practice of recording the residual of a location as a separate element
- 02Keyword index, Sonic Studio Handbook (SFU)supports the terminology used for the residual and for ambience in the field
- 03Late Reverberation, CCRMA (Stanford)supports the late-reverberation tail that a room tone has to match at a seam
Each line points at one specific document. No line is a home page.
Leave this page Close this page once the tone is recorded and slated. There is nothing further to decide on the day.