Aetherial De-Esser overview¶
The Aetherial De-Esser is a TX-only client-side processor that reduces harsh sibilance ("S" and "T" sounds) in your transmitted audio. It works by monitoring a narrow frequency band and ducking it when the signal level in that band exceeds a set threshold.
Before you start¶
- The De-Esser is a TX-only stage. It has no effect on received audio.
- The applet is hidden until the De-Ess stage is enabled. Enable it via the CHAIN widget inside the Aetherial Audio (TXDSP) parent container.
- No radio connection is required to configure the de-esser.
How it works¶
The de-esser uses a sidechain design. A bandpass filter isolates the sibilance band defined by Freq and Q. When the level in that band exceeds the Thresh value, the de-esser attenuates the band by up to the Amount value. The rest of your audio passes through unaffected.
The applet displays two live indicators while you transmit:
- Sidechain response curve — shows the bandpass filter shape with a ball marker at the current centre frequency. As you adjust Freq and Q, the curve and ball update immediately.
- Gain-reduction bar — a horizontal soft-red strip that fills from the right to show how much attenuation is being applied at any moment. The scale runs from 0 to 24 dB; a tick marks the −6 dB point. The meter refreshes approximately 30 times per second.
When the de-esser stage is bypassed, the entire applet tile renders at reduced opacity (approximately 55%) to give a clear visual indication that the stage is inactive. This matches the dim behaviour used by the EQ curve. To bypass or re-enable the de-esser, use the single-click gesture on the DESS stage in the CHAIN widget. Editing is done through the Aetherial Audio Channel Strip.
What each control does¶
| Control | Default | Valid range | Persisted setting | Description |
|---|---|---|---|---|
| Freq | 6000 Hz | 1000 – 12000 Hz | ClientDeEssTxFrequencyHz |
Centre frequency of the sibilance band. Uses logarithmic scaling. Displays as "X.X kHz" at or above 1000 Hz. |
| Q | 2.00 | 0.5 – 5.0 | ClientDeEssTxQ |
Bandwidth of the sibilance band. Higher values produce a narrower band. Uses linear scaling. |
| Thresh | −30.0 dB | −60.0 to 0.0 dB | ClientDeEssTxThresholdDb |
Level above which the de-esser begins attenuating the band. Set this just below your loudest sibilant peaks. |
| Amount | −6.0 dB | −24.0 to 0.0 dB | ClientDeEssTxAmountDb |
Maximum attenuation applied when sibilance is at its peak. Negative values represent reduction; 0 dB means no attenuation. |
| Sidechain response curve | — | — | — | Live display of the bandpass filter shape. The ball marks the current centre frequency. |
| Gain-reduction bar | — | 0 – 24 dB GR | — | Live meter showing current attenuation. Soft-red fill; tick at −6 dB. |
Enabled state is persisted as ClientDeEssTxEnabled.
Tips¶
- Start with Freq at the default 6.0 kHz and sweep it slowly while speaking sibilant words. Watch the gain-reduction bar — maximum deflection indicates you have found the peak sibilance frequency.
- A Q of 2.00 is a reasonable starting point. Increase it to isolate a narrow problem band; decrease it if the sibilance is spread across a wider range.
- Set Thresh so the gain-reduction bar only moves on genuine "S" and "T" sounds, not on normal vowels or consonants.
- The −6 dB tick on the gain-reduction bar marks the default Amount value. Keeping reduction near that tick usually produces transparent results. Larger amounts are available but can make the effect audible as pumping or lisping.
- When the stage is bypassed, the applet tile dims noticeably. If the tile appears dim and you are not hearing de-essing, check that the DESS stage is not bypassed in the CHAIN widget.