AetherDSP Settings

The AetherDSP Settings dialog tunes the advanced parameters of AetherSDR's client-side noise-reduction engines (NR2, NR4, MNR, DFNR, RN2, BNR), letting operators dial in the tradeoff between noise suppression and speech fidelity. The six DSP modules are selectable via a toggle row at the top; clicking a toggle also activates or bypasses that engine.

Before you start

• AetherSDR must be running. A radio connection is not required to change this setting.
• The DSP engine must be active on a receiver for changes to take audible effect immediately.

Opening the dialog

1. Click Settings > AetherDSP Settings....

The dialog appears as a frameless window with a gradient title bar. It remembers its size and position across sessions.

Dialog controls overview

Control	Description
Title bar	Frameless 18 px gradient title bar with a grip glyph (⋮⋮) on the left and the dialog title.
— (Minimize)	Minimizes the dialog.
□ (Maximize)	Maximizes or restores the dialog.
× (Close)	Closes the dialog.
Drag-to-move	Click and drag the title bar to move the dialog. Double-click to toggle maximize/restore.
8-axis resize	Click and drag any edge or corner of the dialog to resize. Cursor changes to indicate the resize direction. 6 px resize hit zone around the inner content widget.

NR2 tab

The NR2 tab controls the musical-noise-reduction engine.

Controls

Control	Kind	Default	Setting key	Behavior
NR2 (tab)	Tab	—	—	Selects the NR2 page. Clicking the NR2 toggle button also activates or bypasses the NR2 engine.
Gain Method	Radio button (Linear, Log, Gamma, Trained)	Gamma	NR2GainMethod	Selects gain-curve mapping used by NR2. Stored as integer 0-3.
NPE Method	Radio button (OSMS, MMSE, NSTAT)	OSMS	NR2NpeMethod	Selects noise power estimator. Stored as integer 0-2.
AE Filter (artifact elimination)	Checkbox	True	NR2AeFilter	Toggles the anti-artefact post-filter.
Reduction:	Slider, 0.50–2.00	1.50	NR2GainMax	Sets maximum NR2 reduction depth. Slider stores value*100 internally.
Gain Floor:	Slider, 0.00–1.00	0.00	NR2GainFloor	Sets the minimum gain floor applied by NR2. Higher values preserve more ambient noise. Added in v26.7.4.
Smoothing:	Slider, 0.50–0.98	0.85	NR2GainSmooth	Controls how smoothly the noise estimate tracks changes.
Threshold:	Slider, 0.05–0.50	0.20	NR2Qspp	Sets speech-presence-probability threshold.
Use Original Geometry	Checkbox	False	NR2UseOriginalGeometry	When enabled, NR2 uses the original spectral geometry (pre-v26.7.4) for noise estimation. Disabled uses the revised geometry for improved musical-noise suppression.
Reset Defaults (↺ icon)	Push button	—	—	Restores NR2 tab defaults (Gamma/OSMS/AE on, 1.50/0.00/0.85/0.20, Use Original Geometry off).

Changing the NPE method

1. Click the NR2 tab.
2. In the NPE Method group, select one of the three radio buttons: OSMS, MMSE, or NSTAT.

The setting takes effect immediately and is saved automatically to NR2NpeMethod.

Adjusting the Gain Floor

The Gain Floor slider (0.00–1.00, default 0.00) sets the minimum gain applied by the NR2 engine. A value of 0.00 allows the engine to fully attenuate noise when the speech-presence probability is low. Higher values preserve more ambient noise, which can reduce the "starved" or "underwater" sound that some operators experience with aggressive noise reduction.

1. Click the NR2 tab.
2. Drag the Gain Floor: slider to the desired level.

The setting takes effect immediately and is saved automatically to NR2GainFloor.

Using the original spectral geometry

The Use Original Geometry checkbox (default: off) controls whether NR2 uses the revised spectral geometry introduced in v26.7.4 (off) or the original pre-v26.7.4 geometry (on). The revised geometry improves suppression of musical-noise artifacts. If you prefer the older behavior, enable this option.

1. Click the NR2 tab.
2. Check or uncheck Use Original Geometry.

The setting takes effect immediately and is saved automatically to NR2UseOriginalGeometry.

NR4 tab

The NR4 tab controls the libspecbleach noise-reduction engine.

Controls

Control	Kind	Default	Setting key	Behavior
NR4 (tab)	Tab	—	—	Selects the NR4 page.
Noise Estimation:	Radio button (MMSE, Brandt, Martin)	MMSE	NR4NoiseEstimationMethod	Selects noise-floor estimator. Stored as integer 0-2.
Adaptive Noise Estimation	Checkbox	True	NR4AdaptiveNoise	Enables continuous re-estimation of the noise floor.
Reduction (dB):	Slider, 0.0–40.0	10.0	NR4ReductionAmount	Sets maximum reduction in dB. Slider stores value*10.
Smoothing (%):	Slider, 0–100	0	NR4SmoothingFactor	Time-domain smoothing of noise estimate.
Whitening (%):	Slider, 0–100	0	NR4WhiteningFactor	Flattens residual noise spectral shape.
Masking Depth:	Slider, 0.00–1.00	0.50	NR4MaskingDepth	Controls spectral-masking depth.
Suppression:	Slider, 0.00–1.00	0.50	NR4SuppressionStrength	Overall suppression strength.
Reset Defaults (↺ icon)	Push button	—	—	Restores NR4 defaults (MMSE/adaptive on, 10 dB, 0, 0, 0.50, 0.50).

MNR tab (macOS only)

The MNR tab controls the macOS MMSE-Wiener noise-reduction engine. The MNR toggle is dimmed on Windows/Linux builds — the engine has no backend on those platforms.

Controls

Control	Kind	Default	Setting key	Behavior
MNR (tab)	Tab	—	—	Selects the MNR page.
Enable MNR (macOS only)	Checkbox	Read live from AudioEngine	MnrEnabled	Enables MMSE-Wiener noise reduction with asymmetric gain smoothing.
Strength	Slider, 0–100	100	MnrStrength	Adjusts MNR aggressiveness (0 mild, 100 max). Persisted as normalized 0.00-1.00.

RN2 tab (informational)

The RN2 tab displays the RNNoise page. It is purely informational with no adjustable parameters. The RN2 engine is enabled via the toggle button at the top of the dialog.

BNR tab (NVIDIA)

The BNR tab controls the NVIDIA Broadcast noise-reduction engine. Intensity is controlled from the overlay menu. The BNR toggle is dimmed on builds without the NVIDIA Broadcast SDK.

DFNR tab

The DFNR tab controls the DeepFilterNet3 noise-reduction engine. The DFNR toggle is dimmed on builds without DeepFilterNet support.

Controls

Control	Kind	Default	Setting key	Behavior
DFNR (tab)	Tab	—	—	Selects the DeepFilterNet3 page.
Attenuation Limit	Slider, 0–100 dB	100	DfnrAttenLimit	Sets maximum noise attenuation. 0 = passthrough; 100 = maximum.
Post-Filter Beta	Slider, 0.00–0.30	0.00	DfnrPostFilterBeta	Applies an additional post-filter for extra suppression. Slider stores value*100 internally.

Notes

• The six DSP toggles (NR2, NR4, MNR, DFNR, RN2, BNR) act as exclusive selectors and engine enable/disable controls. When NR2 is activated, AudioEngine cascades exclusion, disabling DFNR and other mutually exclusive modules.
• The dialog uses PersistentDialog, which automatically saves and restores its geometry across sessions. The dialog position and size are persisted using the AetherDspDialogGeometry setting key.
• All sliders in this dialog use the themable primary slider style, adapting to the current color theme.
• The last active client-side noise-reduction method is remembered across sessions via the LastClientNr setting. If DFNR was last active but DeepFilterNet is unavailable, the preference is cleared automatically.

Tips

• NR2: OSMS works well for steady background noise such as atmospheric hiss or white noise. NSTAT is better for rapidly changing noise floors.
• NR2: If changing the NPE method introduces more musical noise artifacts, enable AE Filter (artifact elimination).
• NR2: If noise reduction sounds too aggressive or "starved," increase Gain Floor: slightly (e.g., 0.05–0.10) to retain some ambient noise.
• NR2: Disable Use Original Geometry (the default) unless you specifically need the pre-v26.7.4 behavior.
• NR4: Adaptive noise estimation helps track changing noise conditions. Disable it if the noise floor is stable.
• DFNR: Post-Filter Beta adds extra suppression but may introduce artifacts at higher values.
• Click the Reset Defaults button (↺) on any tab to return all parameters on that tab to their factory defaults.

Troubleshooting

• Changing parameters produces no audible difference — Confirm the DSP engine is enabled on the receiver. The AetherDSP Settings dialog adjusts parameters but does not itself activate the engine; the engine must be switched on from the receiver controls.
• MNR tab is dimmed or unavailable — MNR is only available on macOS. Windows and Linux builds do not include the MNR backend.
• BNR tab is dimmed — The NVIDIA Broadcast SDK is not installed on this system.
• DFNR tab is dimmed — DeepFilterNet is not available on this build. Rebuild AetherSDR with DeepFilterNet support to enable DFNR.
• Gain Floor slider does not appear — You are running a version older than v26.7.4. Update to the latest release.

Related

• Choosing the right noise reduction: NR2, NR4, DFNR, MNR
• Tune NR2 reduction depth and voice threshold
• Switch NR2 gain method between Linear, Log, Gamma and Trained
• Reset NR2 or NR4 parameters to defaults