DAX Audio Applet¶
Windows note¶
On Windows, AetherSDR does not include a built-in DAX audio driver. The DAX applet displays only the following informational message, and no controls are available:
No built-in DAX driver on Windows. Use TCI, or SmartSDR DAX.
DAX audio routing on Windows is supported through FlexRadio's own SmartSDR DAX drivers or through TCI. See Help > Configuring Data Modes for setup instructions.
On macOS and Linux, the full DAX applet is available as described below.
DAX channels and radio slice capacity¶
The DAX applet shows RX gain/meter rows for DAX channels 1 through 8. Rows above the connected radio's slice capacity are hidden, so a radio with fewer slices does not show dead gain sliders that route nowhere. For example:
- FLEX-6300 / FLEX-6400 (2 slices): DAX 1-2 are shown, DAX 3-8 are hidden.
- FLEX-6600 / FLEX-8600 (4 slices): DAX 1-4 are shown, DAX 5-8 are hidden.
- FLEX-6700 (8 slices): all DAX 1-8 rows are shown.
The hidden rows are not destroyed — they are only hidden, and their gain values are still persisted so they are restored when you connect to a larger radio.
Autostart DAX on Launch¶
Enable the AutoStartDAX setting so that the DAX audio bridge starts automatically every time AetherSDR opens, without requiring a manual click of Enable each session.
Before you start¶
- AetherSDR must be connected to a FLEX-8600 radio. The DAX applet requires an active radio connection.
- The DAX applet must be visible. If it is not, click the DAX tray button on the right sidebar to show it.
Steps¶
- Open the DAX applet by clicking the DAX tray button on the right sidebar if it is not already visible.
- Click Settings > Autostart DAX with AetherSDR to place a check mark next to the item. This persists
AutoStartDAXasTrue. - Confirm the Enable button in the DAX applet shows Enabled (lit green). If it shows Disabled, click it to start the bridge for the current session.
On the next launch, AetherSDR will read AutoStartDAX and activate the bridge automatically, reflecting the enabled state on the Enable button (showing Enabled).
To turn autostart off, click Settings > Autostart DAX with AetherSDR again to remove the check mark.
What each control does¶
| Control | What it does | Default |
|---|---|---|
| Enable button in the DAX applet | Master toggle. Starts or stops the DAX audio bridge for the current session and persists the state. Shows Enabled when active, Disabled when inactive. | Disabled |
| Settings > Autostart DAX with AetherSDR | Checkable menu item. When checked, AetherSDR starts the DAX bridge on every launch. | Off (unchecked) |
| DAX 1 gain+meter | Combined level meter and gain slider for DAX RX channel 1. Drag to adjust. Accessible name: "DAX RX 1 gain". | 0.5 |
| DAX 2 gain+meter | Combined level meter and gain slider for DAX RX channel 2. Drag to adjust. Accessible name: "DAX RX 2 gain". | 0.5 |
| DAX 3 gain+meter | Combined level meter and gain slider for DAX RX channel 3. Drag to adjust. Accessible name: "DAX RX 3 gain". | 0.5 |
| DAX 4 gain+meter | Combined level meter and gain slider for DAX RX channel 4. Drag to adjust. Accessible name: "DAX RX 4 gain". | 0.5 |
| DAX 5 gain+meter | Combined meter/slider; drag to set RX gain on DAX channel 5. | Visible only when the connected radio supports at least 5 slices. |
| DAX 6 gain+meter | Combined meter/slider; drag to set RX gain on DAX channel 6. | Visible only when the connected radio supports at least 6 slices. |
| DAX 7 gain+meter | Combined meter/slider; drag to set RX gain on DAX channel 7. | Visible only when the connected radio supports at least 7 slices. |
| DAX 8 gain+meter | Combined meter/slider; drag to set RX gain on DAX channel 8. | Visible only on an 8-slice-capable radio. |
| TX gain+meter | Combined level meter and gain slider for the DAX TX stream. Drag to adjust. Accessible name: "DAX TX gain". | 0.5 |
| Windows note | On Windows builds the applet shows only the note 'No built-in DAX driver on Windows. Use TCI, or SmartSDR DAX.' (#4112). | Windows has no built-in DAX bridge (no kernel-mode audio driver); all other controls are omitted and their setters are null-guarded. |
Indicator meanings¶
| Indicator | States | Meaning |
|---|---|---|
| DAX 1..8 assignment | — or Slice A..H | The slice (if any) currently assigned to this DAX channel. Displays the slice letter in the active radio model's color. |
| TX assignment | — or Slice A..H | The slice currently holding TX privileges (drives DAX TX). Displays the slice letter in the active radio model's color. |
Tips¶
- The Enable button and Settings > Autostart DAX with AetherSDR both write the same
AutoStartDAXkey. Clicking either one updates the shared setting. - Gain values for all RX channels and the TX channel are saved independently. Adjusting them before enabling autostart means they will be restored at the same levels on the next launch.
- Slice assignment indicators display the slice letter in the active radio model's color (rich text format) for improved visibility. This affects both DAX RX channel assignments and TX assignment indicators.
- On Linux, DAX audio uses PipeWire native streams (
pw_stream) for lower latency, reducing RX latency from approximately 400 ms to approximately 200 ms. This applies to all DAX RX channels. - Each gain slider has an accessible name set for screen reader compatibility: "DAX RX N gain" for channels 1-8 and "DAX TX gain" for the transmit channel.
- The Enable button now dynamically updates its text to show Enabled or Disabled based on the current state, providing clearer visual feedback.
- RX meter levels are exponentially smoothed with fast attack and slow decay for stable, readable metering.
Troubleshooting¶
- The DAX applet is not visible — Click the DAX tray button on the right sidebar to show it.
- Enable is checked but the bridge does not start on the next launch — Verify that Settings > Autostart DAX with AetherSDR has a check mark. Clicking Enable in the applet alone sets the bridge state for the current session and persists
AutoStartDAX, but confirming the menu item is checked ensures the autostart path runs at launch. - The Enable button shows Disabled after launch despite autostart being on — This can occur if AetherSDR launches before a radio connection is established. The DAX applet requires a connected radio. Connect to the radio and click Enable manually, or allow AetherSDR to connect before checking the bridge state.
- Some DAX gain sliders are missing — This is expected when the connected radio supports fewer slices than 8. For example, a FLEX-6600 shows only DAX 1-4. The gain sliders reappear when you connect to a radio with more slice capacity.
- On Windows, the DAX applet shows only a note — This is expected. AetherSDR does not include a built-in DAX audio driver on Windows. Use FlexRadio's SmartSDR DAX drivers or TCI instead. See Help > Configuring Data Modes for details.