BranchOut Audio Documentation
Play audio on multiple speakers simultaneously. Multi-room audio without the expensive hardware.
Free & Open Source
BranchOut is completely free under the MIT License. No trials, no subscriptions, no limits.
Quick Start
- Download and run - No installation required, just run the .exe
- Select speakers - Check the speakers you want to use
- Click Start Branching - Audio plays on all selected speakers
Audio Modes
Basic Mode
- Works immediately - No extra hardware needed
- ~200ms delay - On secondary speakers (not noticeable in different rooms)
- Captures all audio - Windows sounds, music, everything
- Perfect for - Speakers in different rooms
Sync Mode (Zero Latency)
- Perfect sync - All speakers play in perfect synchronization
- Requires - A "silent" USB audio device (any $5 USB adapter works)
- Selective capture - Only captures from the silent device, Windows sounds stay separate
- Perfect for - Speakers in the same room
How to Set Up Sync Mode
- Get any USB audio adapter (cheap $5 ones work fine)
- Open BranchOut and click "Switch to Sync Mode"
- Select the USB adapter as your "Branch Source"
- In your music app (Spotify, etc.), set output to the USB adapter
- Click "Start Branching" - all speakers play in perfect sync
Key Features
- Multi-speaker output - Play audio on 2, 3, 4+ speakers simultaneously
- Per-speaker volume - Individual volume sliders for each speaker
- Global hotkeys - Mute and volume control from anywhere
- Zero configuration - Works out of the box, no drivers needed
- Modern UI - Clean Windows 11 interface
- Low resource usage - ~1-2% CPU during playback
Global Hotkeys
| Hotkey | Action |
|---|---|
| Ctrl+Shift+M | Toggle mute on branched audio |
| Ctrl+Shift+Volume Up | Increase branch volume (+5%) |
| Ctrl+Shift+Volume Down | Decrease branch volume (-5%) |
Troubleshooting
No sound on secondary speakers?
- • Verify speakers appear in Windows Sound settings
- • Click the refresh button in BranchOut
- • Check speaker power and connections
Audio crackling?
- • USB speakers are more stable than Bluetooth
- • Close other audio-heavy applications
- • Try Sync Mode for better quality
Audio delayed or echoing?
- • Different rooms: Use Basic Mode - 200ms delay isn't noticeable
- • Same room: Use Sync Mode for zero latency
- • Mute the main speaker and only use branched speakers
BranchOut doesn't see my speakers?
- • Check they appear in Windows Sound settings
- • Disconnect and reconnect the USB speaker
- • Try a different USB port
- • Restart BranchOut
System Requirements
- OS: Windows 10 (1903+) or Windows 11 (64-bit)
- Runtime: .NET 10 Runtime (or use standalone build)
- RAM: ~50-80 MB
- Audio: Multiple audio devices (USB speakers, Bluetooth, HDMI, etc.)
Configuration
Settings are stored in:
%LocalAppData%\BranchOut\config.jsonNeed Help?
Report issues on GitHub.