Sound Tunnel

Version 1.0.1

Route audio from any application to a virtual microphone for Discord, Zoom, and other voice chat apps.

Perfect for sharing soundboard audio with friends without them needing to hear your microphone.

Features

• Select any application playing audio (Chrome, Spotify, games, etc.)
• Route that audio to a virtual microphone (VB-Cable)
• Dark themed UI
• Volume control
• Optional microphone mixing (your voice + app audio)
• Clean shutdown - stops audio polling when closed

Prerequisites

1. VB-Cable (Required)

Download and install the free virtual audio cable: https://vb-audio.com/Cable/

This creates a virtual audio device that bridges your app audio to Discord.

2. .NET 8.0 Runtime

Download from: https://dotnet.microsoft.com/download/dotnet/8.0

Installation

Option A: Run from Source

git clone <repo-url>
cd SoundAppWin11
dotnet run --project SoundRouter

Option B: Run the Executable

Navigate to SoundRouter/bin/Release/net8.0-windows/ and run SoundTunnel.exe

Usage

1. Launch Sound Tunnel

2. Select Output Device: Choose "CABLE Input (VB-Audio Virtual Cable)"

3. Play Audio: Start playing audio in the app you want to share (e.g., Chrome with a soundboard)

4. Refresh & Select: Click "Refresh" to see apps playing audio, then select the one you want

5. Start Routing: Click "Start Routing" - the audio level bar should respond

6. Configure Discord:

   • Go to Settings > Voice & Video
   • Set Input Device to "CABLE Output (VB-Audio Virtual Cable)"

Your friends will now hear the app audio through your "microphone"!

How It Works

[Chrome/App] → [Default Speakers] → [Sound Tunnel captures] → [VB-Cable Input]
                     ↓                                              ↓
              [You hear audio]                              [VB-Cable Output]
                                                                   ↓
                                                           [Discord Mic Input]
                                                                   ↓
                                                           [Friends hear it]

Sound Tunnel uses WASAPI loopback to copy (not redirect) your system audio. You still hear everything normally while the audio is simultaneously sent to the virtual microphone.

Troubleshooting

No apps in the list

• Make sure an app is actively playing audio
• Click "Refresh" after starting audio playback

VB-Cable not showing

• Restart Sound Tunnel after installing VB-Cable
• Check Windows Sound Settings to verify VB-Cable is installed

Friends can't hear audio

1. Verify "CABLE Input" is selected in Sound Tunnel
2. Verify Discord input is set to "CABLE Output"
3. Check the audio level bar in Sound Tunnel - it should move when audio plays

Echo or feedback

• This shouldn't happen with normal setup
• Make sure you're not routing VB-Cable output back to VB-Cable input

Building from Source

# Clone the repository
git clone <repo-url>
cd SoundAppWin11

# Restore dependencies
dotnet restore

# Build
dotnet build

# Run
dotnet run --project SoundRouter

# Publish release build
dotnet publish -c Release

Tech Stack

• .NET 8.0 WPF
• NAudio for audio capture and routing
• Windows Core Audio API (WASAPI)

License

MIT License - see LICENSE file for details.

Version History

1.0.1

• Initial public release
• Dark theme UI
• Application audio capture via WASAPI loopback
• VB-Cable integration
• Volume control
• Optional microphone mixing
• Auto-detection of VB-Cable
• Filters out Sound Tunnel from app list