AetherDSP Settings¶
The AetherDSP Settings dialog provides advanced control over all six client-side noise-reduction engines in AetherSDR: NR2, NR4, DFNR, MNR, RN2, and BNR. Each engine is selectable via a toggle row at the top of the dialog; clicking a toggle also activates or bypasses that engine.
Opening AetherDSP Settings¶
- Open
Settings > AetherDSP Settings.... - The dialog opens with a frameless title bar by default.
- The dialog can be opened without a radio connection, but the effect is only audible during live reception.
Dialog layout and window controls¶
The AetherDSP Settings dialog uses custom chrome matching the NetworkDiagnosticsDialog and AetherialAudioStrip:
| Control | Description |
|---|---|
| Title bar | 18 px gradient title bar with grip glyph (⋮⋮) on the left and dialog title. Added in v0.9.8 (#2425 refit). |
| — (Minimize) | Minimizes the dialog. |
| □ (Maximize) | Maximizes or restores the dialog. Double-click the title bar also toggles maximize/restore. |
| × (Close) | Closes the dialog. |
| Drag-to-move | Click and drag the title bar to move the dialog. |
| 8-axis resize | Click and drag any edge or corner to resize. Cursor changes to indicate the resize direction. 6 px resize hit zone around the inner content widget. |
The dialog uses PersistentDialog with geometry stored in setting AetherDspDialogGeometry. The position and size are automatically restored when the dialog is reopened.
The dialog background, title bar colors, and slider styling use theme tokens from the active theme. Sliders now use applyPrimarySliderStyle() instead of hardcoded inline stylesheets, making them respect the user's chosen color scheme.
Selecting and activating noise-reduction engines¶
The six DSP toggles (NR2, NR4, MNR, DFNR, RN2, BNR) act as both exclusive tab selectors and engine enable/disable controls. Click a toggle to select its settings page; the same click also activates or bypasses that engine.
When NR2 is activated, AudioEngine enforces cascade exclusion, disabling DFNR and other mutually exclusive modules.
Tab: NR2 — Musical-noise reduction¶
The NR2 engine uses spectral subtraction with gain curve mapping and noise power estimation.
Gain Method¶
Selects the gain-curve mapping used by NR2.
| Option | Description |
|---|---|
| Linear | Linear gain curve |
| Log | Logarithmic gain curve |
| Gamma | Gamma-based gain curve (default) |
| Trained | Pre-trained gain curve |
Stored in setting NR2GainMethod as integer 0-3.
NPE Method¶
Selects the noise power estimator.
| Option | Description |
|---|---|
| OSMS | Optimal smoothing and minimum statistics (default) |
| MMSE | Minimum mean square error |
| NSTAT | Noise statistic-based estimation |
Stored in setting NR2NpeMethod as integer 0-2.
AE Filter (artifact elimination)¶
- Toggle the anti-artefact post-filter.
- Default: On (
True). - Stored in setting
NR2AeFilter.
Reduction:¶
- Sets the maximum NR2 reduction depth.
- Default: 1.50
- Valid range: 0.50–2.00
- Stored in setting
NR2GainMax(value * 100).
Smoothing:¶
- Controls how smoothly the noise estimate tracks changes.
- Default: 0.85
- Valid range: 0.50–0.98
- Stored in setting
NR2GainSmooth.
Threshold:¶
- Sets the speech-presence-probability threshold.
- Default: 0.20
- Valid range: 0.05–0.50
- Stored in setting
NR2Qspp.
Reset Defaults (↺ icon)¶
- Restores NR2 tab defaults: Gamma, OSMS, AE on, Reduction 1.50, Smoothing 0.85, Threshold 0.20.
- Rendered as a flat icon button with anticlockwise arrow (U+21BA).
Tab: NR4 — Libspecbleach noise reduction¶
The NR4 engine uses the libspecbleach library for spectral noise gating.
Noise Estimation:¶
Selects the noise-floor estimator used by NR4.
| Option | Description |
|---|---|
| MMSE | Minimum mean square error (default) |
| Brandt | Brandt noise estimator |
| Martin | Martin noise estimator |
Stored in setting NR4NoiseEstimationMethod as integer 0-2.
Adaptive Noise Estimation¶
- Enables continuous re-estimation of the noise floor.
- Default: On (
True). - Stored in setting
NR4AdaptiveNoise.
Reduction (dB):¶
- Sets maximum NR4 noise reduction in dB.
- Default: 10.0
- Valid range: 0.0–40.0
- Stored in setting
NR4ReductionAmount(value * 10).
Smoothing (%):¶
- Time-domain smoothing of the NR4 noise estimate.
- Default: 0
- Valid range: 0–100
- Stored in setting
NR4SmoothingFactor.
Whitening (%):¶
- Flattens residual noise spectral shape.
- Default: 0
- Valid range: 0–100
- Stored in setting
NR4WhiteningFactor.
Masking Depth:¶
- Controls spectral-masking depth.
- Default: 0.50
- Valid range: 0.00–1.00
- Stored in setting
NR4MaskingDepth.
Suppression:¶
- Overall NR4 suppression strength.
- Default: 0.50
- Valid range: 0.00–1.00
- Stored in setting
NR4SuppressionStrength.
Reset Defaults (↺ icon)¶
- Restores NR4 defaults: MMSE, Adaptive on, 10 dB, 0, 0, 0.50, 0.50.
- Rendered as a flat icon button with anticlockwise arrow (U+21BA).
Tab: MNR — MMSE-Wiener noise reduction¶
The MNR engine provides MMSE-Wiener noise reduction with asymmetric gain smoothing. This tab is dimmed on Windows and Linux builds — the engine has no backend on those platforms.
Enable MNR (macOS only)¶
- Enables MMSE-Wiener noise reduction with asymmetric gain smoothing.
- Initial state is read live from the audio engine.
- Stored in setting
MnrEnabled.
Strength¶
- Adjusts MNR aggressiveness (0 mild, 100 max).
- Default: 100
- Valid range: 0–100
- Stored in setting
MnrStrength(normalized as 0.00–1.00).
Tab: RN2 — RNNoise¶
The RN2 (RNNoise) tab is purely informational — no adjustable parameters are available. The toggle activates or bypasses the RNNoise engine, but settings are managed elsewhere.
Tab: BNR — NVIDIA Broadcast¶
The BNR (NVIDIA) tab shows intensity controlled from the overlay menu. The BNR toggle is dimmed on builds without the NVIDIA Broadcast SDK.
Tab: DFNR — DeepFilterNet3¶
The DFNR tab provides controls for the DeepFilterNet3 noise reduction engine.
Attenuation Limit¶
- Sets maximum noise attenuation applied by DeepFilterNet3.
- Default: 100
- Valid range: 0–100 dB
- 0 = passthrough; 100 = maximum.
- Stored in setting
DfnrAttenLimit.
Post-Filter Beta¶
- Applies an additional post-filter for extra suppression beyond the attenuation limit.
- Default: 0.00
- Valid range: 0.00–0.30
- Stored in setting
DfnrPostFilterBeta(value * 100).
Tips¶
- Start with Post-Filter Beta at or below 0.10. Audible artefacts tend to appear before 0.30 is reached, especially on SSB voice signals.
- If you need stronger overall attenuation without touching the post-filter, increase Attenuation Limit first, then add Post-Filter Beta only for residual noise that remains.
- A value of 0.00 disables the post-filter entirely, leaving DeepFilterNet3's output unchanged.
- For NR2, start with default values and adjust Reduction upward gradually while checking for musical artefacts.
Troubleshooting¶
- Speech sounds hollow or phasey — Post-Filter Beta is set too high. Reduce it toward 0.00 in small increments until naturalness returns.
- No audible change when moving the slider — The selected engine may not be active on the current slice. Confirm the engine toggle is selected and that parameters are not at minimum.
- NR2 produces musical noise — Reduce Reduction or enable AE Filter to suppress artefacts.
- MNR or BNR tabs are dimmed — The required backend (macOS for MNR, NVIDIA Broadcast SDK for BNR) is not available on your platform.
- Colors appear mismatched with the rest of AetherSDR — The dialog now uses theme-aware styling. Try switching themes in
Settings > Appearanceif the colors are not to your liking.