# Routing and virtual devices

VxSound has four application mixer channels: Game, Music (Media), Chat and Aux. A mixer channel is not, by itself, a Windows audio device. Windows-visible endpoints must come from an installed audio driver.

## Current signal path

Each enabled input follows this path:

`App → assigned virtual playback endpoint → WASAPI loopback → format conversion / resampling → channel EQ / bass / treble / fullness → channel level / mute`

All channels then follow one common path:

`Stereo sum → personal L/R EQ for the selected output → master level / headroom → linked sample-peak limiter → physical stereo output`

Each channel also contains a peak limiter before summing. A master limiter after summing handles coincident peaks from multiple channels. The personal layer is not baked into game presets and is not applied repeatedly to the same signal.

VxSound supports output formats between 16 and 192 kHz when the selected device exposes a compatible stereo format. It uses the physical output's current Windows mix rate and explicitly resamples input rates to match. This is not a claim that a headset's hardware supports every rate in that range.

## Setup

1. Install virtual playback devices from a supported vendor, using its official instructions. For example, [VB-Audio's cable page](https://vb-audio.com/Cable/) documents its cable devices and additional independent cables. Follow the vendor's licensing and restart requirements. One cable provides one independent input; leave unused channels unassigned.
2. Leave any unrelated vendor mixer from routing the same virtual signal directly to the headset. Otherwise original and VxSound-processed audio may both be heard.
3. In VxSound, select the real headset/speakers as the physical output. Press Refresh devices after installing or reconnecting devices.
4. Assign one distinct virtual playback endpoint to each desired channel. Missing inputs may be left unassigned. Reusing an input or selecting the physical output as an input is rejected.
5. Play audio in the source application. Open **App Routing** or **Routing Board**, refresh sessions, and explicitly choose the channel (**Apply route** in the list). Alternatively select the same cable in the app or Windows Volume mixer. Apps with a fixed in-app output may need that setting changed or playback restarted.
6. Start the live mixer. Choose an independent profile, volume and mute state for each channel.

This build does not rename Windows devices. “Game”, “Music”, “Chat” and “Aux” in the interface are mixer-channel labels. The drop-down directly underneath each label identifies the actual Windows device to select in other apps.

## App Routing and Routing Board

Both views enumerate playback sessions from the interactive desktop user, across all active playback endpoints. They do not depend on the Windows service's session list. Applications appear after creating an audio session; a running process without an audio session is not enough.

The channel targets come directly from the cable selections in Sound Studio. Each column displays the actual playback device name, or the reason it is unavailable. Unassigned/disconnected cables, duplicate assignments, physical devices used as inputs, feedback routes and inputs with more than two channels are rejected. **Windows Default** remains available to clear a per-app playback preference.

Explicit choices are stored for the current user in `%LOCALAPPDATA%\VxSound\app-routing.json` and applied to Windows per-app preferences in that user's context. VxSound checks saved rules while running and reapplies them to returning audio sessions. Suggestions never change a Windows preference automatically. Windows may require the source app's playback to restart before it moves; the UI reports a saved preference rather than promising an already-moved stream.

The per-app Windows API is optional. If Windows rejects it, use **Windows Volume mixer** or the source application's own output setting. The service no longer writes desktop users' app preferences from its SYSTEM session. If the service mixer is enabled, its playback bindings also use the Sound Studio selections; starting the desktop live mixer stops service mixing first.

VxSound does not include or install a custom virtual audio driver. Install compatible cables separately from their publisher.

## Recovery

Audio errors stop the affected running engine and show the cause. The current version requires a manual refresh/restart after device changes; it does not silently reroute personal EQ to an unverified output.

If an app becomes silent after stopping the mixer, set that app's output back to your physical headset. VxSound changes per-app preferences only for explicit saved choices and does not automatically clear them when it exits. Choose Windows Default in App Routing to clear a saved choice while the app has an audio session. Avoid simultaneously enabling multiple software EQ/surround layers unless you intend their combined effect.