Set the level so that normal dialogue peaks about 20 dB below clipping, then verify that the noise floor lands at least 50 dB below the dialogue peaks; if it does not, fix the room rather than the gain.
Set a dialogue recording level from the room's noise floor
checked 2026-09-16rots yes — figures above moveresponsible Room Tone Register (a named register, not a person)
The arithmetic
Gain is a single number added to everything. Raising it raises the dialogue and the floor together, so the difference between them — the only thing that determines whether the floor is audible — does not change. This is the single most useful fact in location sound, and it is why 'just turn it up' never solves a noisy room.
| Floor − dialogue | What it sounds like after delivery | Verdict |
|---|---|---|
| −60 dB or better | Floor inaudible under dialogue | Excellent |
| −50 dB | Floor just perceptible in the gaps | Acceptable |
| −40 dB | Floor audible; noise reduction needed | Marginal |
| −30 dB | Floor competes with the voice | Unusable |
Setting the level
- Measure the room's floor first. Without it you cannot know what margin you are working with.
- Have the talent speak at the level they will use in the scene. Not a rehearsal whisper, not a projected line.
- Set the peaks about 20 dB below clipping. That is enough headroom for a laugh or a shout without touching the dial mid-take.
- Compute the floor-to-dialogue difference and read it off the table above.
- If the difference is worse than −40 dB, stop and treat the room or move. Nothing downstream will fix it.
Why the delivery target matters here
Delivery specifications for streaming and broadcast set a loudness target for the finished mix, and that target is measured over the whole programme with quiet passages excluded by a gate. A high floor defeats the gate: it stops the quiet passages from being excluded, so the measured loudness of the programme rises and the mix has to be pulled down, which in turn makes the dialogue quieter against the room. The failure compounds, and it starts with the floor.
Do not use a delivery target as a recording level. A delivery target is measured after the mix; using it as a recording aim produces a track with no headroom and no ability to absorb a loud take.
Source log
- 01ITU-R BS.1770: Algorithms to measure audio programme loudnesssupports the gated loudness measurement that a high noise floor defeats
- 02EBU R 128: Loudness normalisation and permitted maximum level (PDF)supports the broadcast loudness and true-peak limits referenced in the delivery discussion
- 03EBU R 128 publication page (European Broadcasting Union)supports the publication behind the loudness recommendation cited here
Each line points at one specific document. No line is a home page.
Leave this page Close this page once the level is set and the margin computed. A margin under 40 dB is a room problem, not a level problem.