De-esser

The de-esser tames sibilance, the hard “s”, “sh” and “t” sounds a close microphone exaggerates. It listens to the sound above its frequency and turns only that band down while it’s over the threshold, so the rest of the voice keeps its level.

Where: Clip tab ▸ Sound ▸ De-esser
Agent tools: set_audio

Reduce sibilance

Select a clip with sound, and open the De-esser section of the Sound tab.
Tick Reduce sibilance. It starts at 6,000 Hz, a threshold of 0 dB and a range of 6 dB.
Play a part with hard “s” sounds. If they’re still sharp, lower Threshold or raise Range.
If the voice sounds dull or lisped, raise Threshold or lower Range. Move Frequency to where the sibilance sits in this voice.

The other controls are greyed out until Reduce sibilance is ticked. Reset in the section’s header turns the de-esser off.

The controls

Control	What it does	Range	Default	Quick picks
Frequency	Where the sibilant band starts.	2,000 to 12,000 Hz	6,000 Hz	4,000, 5,000, 6,000, 8,000
Threshold	How loud the band must get, relative to the clip’s loudness, before it’s turned down.	−30 to +20 dB	0 dB	−6, −3, 0, 3
Range	The most the band is turned down.	1 to 24 dB	6 dB	3, 6, 10

The de-esser never makes any frequency louder. Right at Frequency it takes less than half the range, about 2.5 dB of the default 6 dB, and about 5.5 dB an octave above.

It reacts in 1 ms and lets go over 60 ms. You can’t change those times.

Read Status and Loudness

Threshold follows the clip’s own loudness, the way the Gate’s does, so a trim, a pan change or a different channel choice moves it. Two readouts show what it means for this clip. With several clips selected, Loudness reads “—”. Status does too, unless the de-esser is off on the first of them, when it reads “off”.

Loudness is the level the threshold is measured from, for example “−41.7 LUFS”. It reads “measuring…” until the clip has been measured.

Status says where the de-esser acts, or why it isn’t working:

Status	What it means
off	Reduce sibilance isn’t ticked.
Acts above −41.7 dBFS	The clip’s loudness plus the Threshold.
Waits for its loudness	The clip hasn’t been measured yet.
Not de-essing: too short	The clip plays for under 0.4 s, too short to measure.
Not de-essing: too quiet	The clip is too quiet to measure.
Not de-essing: no sound	The clip plays no sound in this timeline, or it’s a nest clip.

Until the clip’s loudness is measured it plays without the de-esser, and an export waits. See Before the clip’s loudness is measured.

Good to know

The de-esser runs after the gate and the leveller, and before the compressor. See How audio works.
With an action selected, these controls set where the action ends. The numbers glide across the action, and turning the de-esser on or off changes at the action’s end.
The de-esser does nothing on a nest clip. Open the nest with ⌘↓ and set it on the clips inside.

With an agent

set_audio sets the same controls through de_esser, with frequency, threshold_db and range_db. An empty de_esser turns it on at the defaults and null turns it off. See Tools: clip sound.