Aetherial Parametric EQ (TX / RX)¶
The Aetherial Parametric EQ is a client-side equalizer with two independent copies: Aetherial TX EQ and Aetherial RX EQ. Each docked tile (minimum 110 px tall) shows the summed EQ response with a live FFT analyzer overlay (including a peak-hold trace). All editing happens in the frameless ClientEqEditor floating window (titled "Aetherial Parametric EQ — TX" or "— RX").
Bypass the EQ stage from the chain¶
This section explains how to bypass the client-side parametric EQ for either the TX or RX audio path. Bypassing removes the EQ from the signal chain without deleting your band settings.
Before you start¶
- AetherSDR must be open. A radio connection is not required to bypass the EQ.
- The EQ stage must already be present in the CHAIN widget for the path you want to bypass (TX or RX).
Steps¶
- Locate the CHAIN widget for the path you want to bypass — either the TX chain or the RX chain.
- Single-click the EQ stage in the CHAIN widget for that path.
The EQ stage is now bypassed for that path. The ClientEqTxEnabled or ClientEqRxEnabled setting is updated immediately and persisted across restarts.
To re-engage the EQ, single-click the EQ stage in the CHAIN widget again.
What each control does¶
| Control | Path | Persisted key |
|---|---|---|
| EQ stage (TX chain) | TX | ClientEqTxEnabled |
| EQ stage (RX chain) | RX | ClientEqRxEnabled |
| Output Fader | Vertical combined fader + level meter on the right edge of the floating editor. Drag to set post-EQ master gain; scroll wheel adjusts in 0.5 dB steps; double-click resets to 0 dB. Click the dB readout at the bottom to edit the gain numerically: type a value and press Enter or click away to commit (clamped to -36 to +12 dB range). Press Escape to cancel editing. The level bar behind the handle shows the smoothed post-EQ peak in real time with the same green-amber-red gradient as the Tube level meter. | Persisted separately per path: ClientEqTxMasterGain / ClientEqRxMasterGain. Tooltip: 'Output gain (dB). Drag to set, wheel for fine step, double-click to reset to 0 dB, or click the readout to type a value.' Gain range is linear 0.0 to ~4.0; the scale labels run from -40 to 0 dB. Located in the floating editor only — not in the docked applet tile. |
| Peak Hold | Located in the floating editor header strip only. When checked, the per-bin peak-hold trace in the analyzer stops decaying — every frequency's highest observed level is held until the button is toggled off. Button background turns amber when checked. | None (not persisted). |
| Filter family | Located in the floating editor header strip. Selects the HP/LP cascade mathematics: Butterworth (maximally flat passband), Chebyshev (steeper rolloff with 1 dB passband ripple), Bessel (linear phase / gentler rolloff), or Elliptic (steepest transition with ripple in both bands). Applies only to HP and LP filter types; peak and shelf bands use their own fixed 2nd-order topology regardless. Default: Butterworth. | Persisted separately per path: ClientEqTxFilterFamily / ClientEqRxFilterFamily. |
| Reset | Located in the floating editor header strip. Resets all bands to the default 10-band template, restores the default band count, and resets the Filter family to Butterworth. Saves immediately. Tooltip: 'Reset all bands to default values'. | Affects ClientEqTxBands / ClientEqRxBands and ClientEqTxFilterFamily / ClientEqRxFilterFamily. |
| Smoothing | Applies fractional-octave power-averaging to the analyzer trace for display — does not affect EQ math. Lower fraction = smoother (⅓ is most smoothed; 1/96 is effectively off). Shared between TX and RX editors. Smoothing is applied after the peak-hold update each frame, so both the live analyzer trace and the peak-hold trace are smoothed for display while peak detection itself remains sample-accurate. | ClientEqSmoothingFraction. Tooltip: 'Fractional-octave smoothing applied to the analyzer trace. Lower fraction = smoother (⅓ = most, 1/96 = off). Affects display only — EQ math is unchanged.' Located in the editor header strip (floating editor only). |
| Filter-type icon row | A row of 8 custom-painted icons (one per band slot) at the top of the editor canvas area. Each icon draws the current filter shape (peak bell, shelf ramp, HP/LP slope) in its band's palette colour. Click an icon to cycle through the filter types for that band; clicking also selects the band, highlighting its handle on the canvas and its column in the parameter row. | Located in the floating editor only. Icons dim to 35 % opacity when the band is bypassed. Implemented by ClientEqIconRow. |
| Parameter text row | A row of 8 text columns (one per band slot) below the canvas showing each band's Freq, Gain, and Q values. Values update live during canvas drags. Clicking a column selects that band. Right-click a column to open an inline edit menu; committing a numeric value there saves the EQ settings immediately. Each column has a transparent background so it does not bleed a dark fill over the canvas's band-plan strip directly above it. | Located in the floating editor only. Implemented by ClientEqParamRow. |
| Filter cutoff guide lines (TX / RX) | Dashed yellow vertical lines overlaid on the canvas at the radio's current TX low/high filter cutoff (TX tile) or RX passband edges (RX tile). Hovering near a line changes the cursor to a horizontal-resize arrow. Dragging a line in the editor moves the radio's corresponding filter cutoff in real time. The docked applet tiles also display these guide lines: the TX tile receives cutoffs via setTxFilterCutoffs, and the RX tile receives them via setRxFilterCutoffs. |
Dragging the TX cutoff guides emits cutoffsDragRequested(Tx, lo, hi), which MainWindow forwards to TransmitModel. Dragging the RX guides writes to the active SliceModel. Pass 0 for an edge to suppress that guide. |
| Reference curve | Located in the floating editor header strip. Selects a visual reference overlay curve to guide EQ shaping. Options: Off, AT&T 1959, Heil DX, Astatic D-104, Shure 444, or Heil HC-5. Each curve is an amplitude-vs-frequency trace drawn in amber on the editor canvas, behind the user's band curves. The reference is for display only — it does not affect EQ math or audio processing. Default: Off. | Persisted separately per path: ClientEqTxReferenceCurve / ClientEqRxReferenceCurve. |
Band data is stored separately in ClientEqTxBands and ClientEqRxBands and is not affected by bypass.
Indicator elements¶
| Indicator | States | Meaning |
|---|---|---|
| Summed EQ response | flat (cyan 0 dB line), shaped (cyan curve) | Cumulative frequency response of all enabled bands for this tile's path. Dims to grey when the EQ stage is bypassed. |
| Live analyzer overlay | idle (no fill), running (cyan gradient fill) | Real-time FFT of audio passing through this tile's path, filled from 0 dB (top, cyan) fading to transparent at the bottom. Refreshed at 25 Hz (40 ms timer). |
| Peak-hold trace | decaying (off-white line moving down ~10 dB/sec), frozen (stationary at max level when Peak Hold is checked) | Per-frequency maximum energy seen since the last reset, helping identify resonances and harsh peaks while tuning. Tracks raw bins even when display smoothing is enabled. |
| Filter cutoff guide lines | absent (cutoff = 0 or not set), dashed yellow vertical line | Marks the radio's current TX low/high filter cutoff (TX tile) or RX passband edges (RX tile) directly on the EQ canvas so you can see where the radio is rolling off the signal. |
| Audio band-plan strip | always visible at bottom of canvas | 14 px strip at the bottom of the EQ canvas showing E-SSB / SSB / AM-FM modulation regions as a reference; cursor interaction in this area is excluded from band-handle hit-testing. |
| Reference curve overlay | off (hidden), active (amber semi-transparent curve) | Visual target curve displayed behind the user's band curves on the editor canvas. Preset curves include AT&T 1959, Heil DX, Astatic D-104, Shure 444, and Heil HC-5. Display only — no effect on EQ math. |
Reference curve presets¶
The reference curve overlay helps you shape your EQ toward a known target response. Each preset is a digitised amplitude-vs-frequency trace derived from a classic microphone or telecommunications standard.
| Preset name | Description |
|---|---|
| Off | No reference overlay shown. |
| AT&T 1959 | AT&T's 1959 "optimum transmission frequency response for speech" — a canonical Bell Labs presence-peak target. Peak +5 dB at 2.5 kHz, rolls off below 300 Hz and above 3.4 kHz. |
| Heil DX | Bob Heil's published recommendation for maximum talk power in pile-ups. Sharper +6 dB peak at 2.7 kHz, more aggressive low-cut than AT&T 1959. |
| Astatic D-104 | The classic "lollipop" crystal microphone response — extremely peaky presence around 3 kHz (+10 dB) with deep low-end rolloff. |
| Shure 444 | Classic broadcast-style desk microphone response — broader response with gentler presence boost (+4 dB around 3 kHz). |
| Heil HC-5 | Modern dynamic SSB mic element response — mid-presence boost peaks around 3 kHz at +5 dB. |
Tips¶
- The bypass state is per-path. Bypassing the TX EQ does not affect the RX EQ, and vice versa.
- The "Aetherial TX EQ" and "Aetherial RX EQ" applet tiles are hidden when their matching EQ stage is not enabled. If a tile disappears after bypassing, this is expected behavior.
- The floating editor ("Aetherial Parametric EQ — TX" or "— RX") can still be opened via double-click on the CHAIN widget stage even when bypassed, so you can continue editing bands without re-engaging the EQ.
- The peak-hold trace in the analyzer decays at approximately 10 dB/sec during normal operation. Peak detection always operates on raw, unsmoothed bins so it is sample-accurate; smoothing is applied separately for display purposes only. Enable Peak Hold in the floating editor to freeze the trace at its highest observed level per frequency bin — useful for identifying resonances while tuning bands.
- The parameter text row columns use a transparent background. This prevents the dark application stylesheet fill from overlapping the band-plan strip at the bottom of the EQ canvas above the row.
- Clicking Reset in the floating editor is permanent and takes effect immediately. There is no undo. The reset also sets the Filter family back to Butterworth for that path.
- To set the Output Fader gain numerically, click the dB readout at the bottom of the fader. The display switches to a bare number (e.g. "0.0"). Type a value and press Enter to commit (clamped to the -36 to +12 dB range). Press Escape to cancel and restore the previous value. The inline edit behaves identically to the ClientCompKnob numeric entry.
- Reference curves are visual guides only. They do not affect EQ math or audio processing. Select a curve to use as a shaping target, then adjust your parametric bands to match.