Narrow or widen the sidechain band with Q¶

The Q knob controls how wide or narrow the sidechain bandpass filter is around the sibilance centre frequency. A higher Q focuses attenuation on a tighter slice of the spectrum; a lower Q affects a broader band. Adjust Q after locating the sibilance peak with Freq so the de-esser targets exactly the right content without dulling nearby consonants.

Before you start¶

The Aetherial De-Esser (DESS) stage must be enabled and visible. It appears as a sub-container inside the Aetherial Audio (TXDSP) parent container.
If the applet is not visible, open the Aetherial Audio Channel Strip, which hosts the de-esser controls directly. The floating StripDeEssPanel (accessible through the Channel Strip) includes the Slop button; the docked Aetherial De-Esser applet omits the Attack, Release, and Slope knobs/buttons.
To bypass the de-esser, single-click the DESS stage in the CHAIN widget. When bypassed, the entire applet tile dims to approximately 55 % opacity as a visual indicator.
Set the centre frequency with Freq before fine-tuning Q. See Sweep Freq to locate peak sibilance.
The de-esser is available in two side-specific instances: TX (for transmitted audio) and RX (for received audio). The TX version is labeled "Aetherial De-Esser" and the RX version "Aetherial De-Esser — RX". Both share identical controls and behaviour. The RX instance is reachable through the Aetherial Audio Channel Strip.

Steps¶

Open the Aetherial De-Esser applet inside the Aetherial Audio Channel Strip. Use showForTx() to access the TX instance or showForRx() to access the RX instance.
Locate the Q knob in the six-knob tuning row (Freq, Q, Thresh, Amount, Attack, Release). Note: In the docked ClientDeEssApplet, only Freq, Q, Thresh, and Amount are present; Attack and Release are omitted.
Rotate Q clockwise to increase the value and narrow the sidechain band, or counter-clockwise to decrease the value and widen it.
Watch the sidechain response curve — the bandpass peak broadens or sharpens as Q changes.
While transmitting or speaking a sibilant phrase, observe the gain-reduction bar to confirm the de-esser is still triggering at the adjusted bandwidth. See Watch live GR while reading a sibilant phrase.

What each control does¶

Control	Default	Valid range
Freq	6000 Hz	1000 to 12000 Hz
Q	2.00	0.5 to 5.0
Thresh	-30.0 dB	-60.0 to 0.0 dB
Amount	-6.0 dB	-24.0 to 0.0 dB
Attack	1.0 ms (present in the Channel Strip StripDeEssPanel RX and TX only; omitted from the docked ClientDeEssApplet)	0.1 to 30.0 ms
Release	100 ms (present in the Channel Strip StripDeEssPanel RX and TX only; omitted from the docked ClientDeEssApplet)	10.0 to 500.0 ms
Sidechain response curve	—	—
Gain-reduction bar	—	0 to 24 dB GR
Slope	24 dB/oct (2 stages). Cycles the sidechain bandpass cascade count. Each stage adds 12 dB/oct of rolloff outside the sibilant band. Higher slope = narrower effective notch, less mid-band collateral on Ess-heavy phrases.	12 / 24 / 36 / 48 dB/oct (1 to 4 stages). Present as a push button labeled "N dB/oct" in the floating StripDeEssPanel only, anchored below the Thresh knob. Present for both TX and RX paths. Persisted as ClientDeEssTxSlopeStages / ClientDeEssRxSlopeStages.

Value entry via inline text editor¶

All knobs in the Aetherial De-Esser support direct numeric entry through an inline text editor:

Activate the editor: Click any knob's current value text. The value area gains focus and a subtle dark inset with a cyan border appears, indicating edit mode.
Enter a value: Type the desired numeric value. The editor accepts locale-aware decimal formats (e.g., "12,5" in comma-decimal locales) and tolerates extra characters such as unit labels (e.g., "2.00" or "2.00 ms").
Commit the value: Press Enter or click anywhere outside the editor. The value is clamped to the knob's valid range and applied immediately.
Cancel: Press Escape to revert to the previous value without committing.

This feature provides precise, one-step adjustment without rotating the knob, especially useful for recalling saved settings or matching a known value.

Bypass dimming¶

When the DESS stage is bypassed via a single-click in the CHAIN widget, the entire applet tile renders at reduced opacity (approximately 55 %). This matches the dim behaviour used on the EQ curve and gives a clear at-a-glance indication that the stage is inactive. Click the DESS stage again in the CHAIN widget to re-enable it and restore full opacity.

Slope (notch filter steepness)¶

The Slope button controls how many cascaded bandpass biquad stages the sidechain uses. Each stage adds 12 dB/oct of rolloff outside the sibilant band. Click the button to cycle through the options: 12 → 24 → 36 → 48 dB/oct (1 to 4 stages). A higher slope narrows the effective notch, reducing collateral attenuation on mid speech band content during Ess-heavy phrases.

The Slope button appears in the floating StripDeEssPanel only, anchored at the bottom of the left knob column below the Thresh knob. It is not present in the docked Aetherial De-Esser applet. Slope is persisted independently for TX and RX with keys ClientDeEssTxSlopeStages and ClientDeEssRxSlopeStages.

Tips¶

Start at the default of 2.00 and increase Q only if attenuation is spilling onto vowels or other consonants adjacent to the sibilance band.
Very high Q values (above 4.0) can make the de-esser miss slightly off-centre sibilants. If GR stops triggering reliably, lower Q slightly or re-sweep Freq.
The response curve gives immediate visual feedback — use it to judge whether the bell is too broad or too sharp before committing to a setting.
Settings are saved independently for TX and RX instances via separate setting keys: ClientDeEssTxQ for TX and ClientDeEssRxQ for RX.
Use the inline value editor (click the current value) for precise numeric entry when you know the exact Q you need.
Combine a higher Slope (36 or 48 dB/oct) with moderate Q to concentrate the de-esser action only on pure sibilant frequencies, leaving adjacent consonants untouched.