AetherDSP Settings¶
The AetherDSP Settings dialog (Settings > AetherDSP Settings...) controls the client-side noise-reduction engines built into AetherSDR: NR2, NR4, MNR, RN2, BNR, and DFNR. Open it at any time; a radio connection is not required to change these parameters. All values are saved automatically when you close the dialog. The six DSP modules are selectable via a toggle row at the top; clicking a toggle also activates or bypasses that engine.
The dialog uses a custom frameless title bar with window controls matching the chrome family of NetworkDiagnosticsDialog and AetherialAudioStrip. Dialog position and size are persisted automatically between sessions. Drag the title bar to move the dialog; double-click the title bar to toggle maximize/restore. Drag any edge or corner to resize (6 px resize hit zone around the inner content widget).
The dialog and all its controls are themed using the current AetherSDR theme. The dialog background uses the dialog/aetherDsp theme color set, and sliders use the applyPrimarySliderStyle() style function instead of a hard-coded dark stylesheet.
Before you start¶
- AetherSDR must be running.
- Decide which noise-reduction engine is active for your slice before tuning its parameters. Adjusting a disabled engine has no audible effect.
Opening the dialog¶
- Click
Settings > AetherDSP Settings.... - The AetherDSP Settings dialog opens. Select the tab for the engine you want to adjust.
NR2 tab¶
NR2 is the musical-noise-reduction engine. Click the NR2 tab to access its controls.
Controls¶
| Control | Kind | Default |
|---|---|---|
| Gain Method | Radio buttons | Gamma |
| NPE Method | Radio buttons | OSMS |
| AE Filter (artifact elimination) | Checkbox | Enabled |
| Reduction: | Slider | 1.50 |
| Smoothing: | Slider | 0.85 |
| Threshold: | Slider | 0.20 |
| Reset Defaults (↺ icon) | Button (flat icon) | — |
Control descriptions¶
Gain Method selects the gain-curve mapping NR2 uses. NR2GainMethod is stored as an integer: Linear = 0, Log = 1, Gamma = 2, Trained = 3. Gamma suits most voice modes.
NPE Method selects the noise power estimator. NR2NpeMethod is stored as an integer: OSMS = 0, MMSE = 1, NSTAT = 2.
AE Filter (artifact elimination) toggles the anti-artefact post-filter (NR2AeFilter). Leave this enabled unless you are specifically testing raw NR2 output.
Reduction: (NR2GainMax) sets the maximum reduction depth NR2 can apply. Higher values suppress more noise but can affect speech naturalness.
Smoothing: (NR2GainSmooth) controls how quickly the noise estimate tracks signal changes. Higher values produce smoother but slower tracking.
Threshold: (NR2Qspp) sets the speech-presence-probability threshold below which NR2 treats audio as noise. Raise this if speech is being suppressed; lower it if noise breaks through during pauses.
Reset Defaults (↺ icon) restores the NR2 tab to its factory values: Gain Method = Gamma, NPE Method = OSMS, AE Filter = enabled, Reduction = 1.50, Smoothing = 0.85, Threshold = 0.20.
Steps — adjust NR2 reduction depth¶
- Open
Settings > AetherDSP Settings.... - Click the NR2 tab.
- Drag the Reduction: slider to the desired value (default 1.50).
- Close the dialog. The value is saved automatically.
NR4 tab¶
NR4 uses the libspecbleach library. On Windows, NR4 requires LLVM (clang-cl) to compile; if LLVM is not installed, the NR4 toggle is dimmed with a tooltip instructing you to install LLVM from llvm.org and rebuild. Click the NR4 tab to access its controls.
Controls¶
| Control | Kind | Default |
|---|---|---|
| Noise Estimation: | Radio buttons | MMSE |
| Adaptive Noise Estimation | Checkbox | Enabled |
| Reduction (dB): | Slider | 10.0 |
| Smoothing (%): | Slider | 0 |
| Whitening (%): | Slider | 0 |
| Masking Depth: | Slider | 0.50 |
| Suppression: | Slider | 0.50 |
| Reset Defaults (↺ icon) | Button (flat icon) | — |
Control descriptions¶
Noise Estimation: selects the noise-floor estimator NR4 uses. NR4NoiseEstimationMethod is stored as an integer: MMSE = 0, Brandt = 1, Martin = 2.
Adaptive Noise Estimation (NR4AdaptiveNoise) enables continuous re-estimation of the noise floor. Enable this when the noise floor varies rapidly.
Reduction (dB): (NR4ReductionAmount) sets the maximum noise reduction NR4 applies in decibels. At 0.0 dB NR4 applies no attenuation; at 40.0 dB it applies the maximum available suppression. The default of 10.0 dB suits most SSB conditions.
Smoothing (%): (NR4SmoothingFactor) applies time-domain smoothing to the NR4 noise estimate. If raising NR4ReductionAmount causes musical noise, try increasing this first.
Whitening (%): (NR4WhiteningFactor) flattens the spectral shape of residual noise after suppression.
Masking Depth: (NR4MaskingDepth) controls the spectral-masking depth.
Suppression: (NR4SuppressionStrength) sets overall NR4 suppression strength.
Reset Defaults (↺ icon) restores the NR4 tab to its factory values: Noise Estimation = MMSE, Adaptive Noise Estimation = enabled, Reduction = 10.0 dB, Smoothing = 0, Whitening = 0, Masking Depth = 0.50, Suppression = 0.50.
Steps — adjust NR4 reduction amount¶
- Open
Settings > AetherDSP Settings.... - Click the NR4 tab.
- Drag the Reduction (dB): slider left to decrease suppression or right to increase it. The current value is shown to the right of the slider.
- Close the dialog. The value is saved automatically.
Tips¶
- Start near the default of 10.0 dB and increase in small steps while monitoring audio quality. Values above 25–30 dB can introduce processing artifacts on weaker signals.
- Smoothing (%): and Suppression: interact with the reduction amount. If raising
NR4ReductionAmountcauses musical noise, try increasing smoothing first. - Enable Adaptive Noise Estimation when the noise floor varies rapidly so NR4 re-estimates the floor continuously.
MNR tab¶
MNR is the MMSE-Wiener noise-reduction engine with asymmetric gain smoothing. It is available on macOS only. On Windows and Linux builds the MNR toggle is dimmed — the engine has no backend on those platforms. Click the MNR tab to access its controls.
Controls¶
| Control | Kind | Default |
|---|---|---|
| Enable MNR (macOS only) | Checkbox | Read from audio engine |
| Strength | Slider | 100 |
Control descriptions¶
Enable MNR (macOS only) (MnrEnabled) enables the MMSE-Wiener noise reduction engine with asymmetric gain smoothing. The initial state of the checkbox reflects the current state of the audio engine at the time the dialog opens.
Strength (MnrStrength) adjusts MNR aggressiveness. 0 is mild suppression; 100 is maximum suppression. The value is persisted internally as a normalized 0.00–1.00 range.
RN2 tab¶
The RN2 tab displays information about the RNNoise engine. There are no adjustable parameters on this tab.
BNR tab¶
The BNR tab displays information about the NVIDIA noise-reduction engine. BNR intensity is controlled from the overlay menu, not from this dialog. On builds without the NVIDIA Broadcast SDK the BNR toggle is dimmed.
DFNR tab¶
DFNR uses the DeepFilterNet3 neural network for noise reduction. Click the DFNR tab to access its controls.
Controls¶
| Control | Kind | Default |
|---|---|---|
| Attenuation Limit | Slider | 100 |
| Post-Filter Beta | Slider | 0.00 |
Control descriptions¶
Attenuation Limit (DfnrAttenLimit) sets the maximum noise attenuation DeepFilterNet3 may apply. At 0 the output is passed through unchanged; at 100 the maximum attenuation is applied.
Post-Filter Beta (DfnrPostFilterBeta) applies an additional post-filter for extra suppression beyond what DeepFilterNet3 provides on its own. At 0.00 the post-filter is inactive. The value is stored internally multiplied by 100.
Troubleshooting¶
- Slider has no audible effect — confirm that the engine whose tab you are adjusting is the active noise-reduction engine for your slice. Enabling another engine simultaneously may mask its contribution.
- Speech sounds hollow or distorted at high NR4 reduction values — lower Reduction (dB): and enable Adaptive Noise Estimation so the noise floor estimate stays accurate.
- MNR controls are grayed out — MNR is available on macOS only. On Linux and Windows the MNR tab is informational.
- NR4 toggle is grayed out on Windows — NR4 requires LLVM (clang-cl) to compile. Install LLVM from llvm.org and rebuild AetherSDR to enable NR4.
- Changes appear to reset — each tab has a Reset Defaults button. Verify you have not accidentally clicked it.
- Slider appearance does not match screenshots — the dialog now uses themed slider styling via
applyPrimarySliderStyle(). The slider colors follow the current theme rather than a hard-coded color scheme. To change slider appearance, change your active theme in AetherSDR's theme settings.