DAX Audio applet¶

The DAX Audio applet shows per-channel RX meters and gain sliders for DAX 1-4 plus a single TX meter, with a master Enable toggle that persists as AutoStartDAX. It also displays slice-assignment indicators so you can confirm at a glance which slice is routed where without leaving the main window.

Before you start¶

AetherSDR must be connected to the radio. The slice-assignment indicators require a live radio connection.
At least one slice must have a DAX channel assigned. If no slices are assigned, all indicators show —.
AetherSDR v26.5.2.1 or later renders slice letters with rich text formatting for improved visibility.

Platform-specific behavior¶

Windows¶

On Windows, AetherSDR does not include a built-in DAX audio bridge. The DAX Enable button, per-channel meters, gain sliders, and slice-assignment indicators are not functional because the necessary kernel-mode audio driver is only shipped on macOS and Linux. Instead, the applet shows only the notice:

No built-in DAX driver on Windows. Use TCI, or SmartSDR DAX.

To set up DAX on Windows, use FlexRadio's own SmartSDR DAX drivers. For guidance, see Help > Configuring Data Modes.

macOS and Linux¶

On macOS and Linux, the full DAX Audio applet is available. In v0.9.7 (Linux), DAX RX latency drops from approximately 400 ms to approximately 200 ms via a native PipeWire pw_stream source path, replacing the previous PulseAudio client.

Steps¶

Click the DAX tray button on the right sidebar to open the DAX Audio applet.
On macOS or Linux, to enable DAX audio routing:
Click DAX Enable. The button text changes from "Disabled" to "Enabled".
AetherSDR saves the setting as AutoStartDAX in application settings. The DAX audio bridge starts and emits daxToggled.
Look at the status label to the right of each channel label (DAX 1:, DAX 2:, DAX 3:, DAX 4:).
Read the indicator for each channel. It shows either — (no slice assigned) or Slice A through Slice H (the letter of the slice currently routed to that channel). In v26.5.2.1, the slice letter may be displayed using rich text formatting for better legibility.
To see which slice is driving the DAX TX stream, read the status label on the TX: row. It follows the same format: — or Slice A through Slice H.
To adjust RX gain on a DAX channel, drag the meter/slider for that channel. The gain value persists in application settings (DaxRxGain1 through DaxRxGain4).
To adjust TX gain on the DAX TX stream, drag the TX gain+meter slider. The gain value persists as DaxTxGain.
To disable DAX audio routing, click DAX Enable again. The button text changes from "Enabled" back to "Disabled".

What each control does¶

Control	Kind	Default	Range	Setting key	Behavior
DAX Enable	Toggle button	Off	—	`AutoStartDAX`	Starts or stops the DAX audio bridge. Button text shows "Enabled" or "Disabled" reflecting current state. Not functional on Windows.
DAX 1 gain+meter	Meter/slider	0.5	0.0–1.0	`DaxRxGain1`	Drag to set RX gain on DAX channel 1.
DAX 2 gain+meter	Meter/slider	0.5	0.0–1.0	`DaxRxGain2`	Drag to set RX gain on DAX channel 2.
DAX 3 gain+meter	Meter/slider	0.5	0.0–1.0	`DaxRxGain3`	Drag to set RX gain on DAX channel 3.
DAX 4 gain+meter	Meter/slider	0.5	0.0–1.0	`DaxRxGain4`	Drag to set RX gain on DAX channel 4.
TX gain+meter	Meter/slider	0.5	0.0–1.0	`DaxTxGain`	Drag to set TX gain on the DAX TX stream.

Indicator	Location	Possible values	Persisted setting
Slice-assignment status (per channel)	Right of DAX 1: – DAX 4: labels	`—` or `Slice A`–`Slice H`	None
TX assignment status	Right of TX: label	`—` or `Slice A`–`Slice H`	None

These indicators are read-only. They update automatically when a slice's DAX channel assignment changes. Slice-to-channel assignment is configured on the slice itself, not in this applet.

Tips¶

The indicators update in real time. If you change a slice's DAX channel assignment on the radio or in another part of the UI, the applet reflects the change immediately without requiring a manual refresh.
A channel showing — means no slice is currently assigned to it; audio will not flow on that channel.
Starting with v26.5.2.1, slice letters in the status indicators may use rich text formatting. This is an internal change; you do not need to adjust any settings to see the indicators correctly.
The DAX Audio applet uses theme styling (class applet/dax). If you customize your application theme, the applet's appearance may vary to match the rest of the UI.
Accessibility labels have been added: the DAX Enable button is labeled "DAX enable" with description "Enable or disable DAX digital audio routing", and the RX gain sliders are labeled "DAX RX 1 gain" through "DAX RX 4 gain" and the TX gain slider as "DAX TX gain" to improve compatibility with screen-reader software.