Lichen

Multi-headphone audio router for Linux

Route audio to multiple headphones simultaneously and mix multiple microphones into a single virtual input. Perfect for pair programming, shared listening, or video calls with multiple participants.

Features

• Combined Output — Route system audio to multiple headphones/speakers at once
• Mixed Input — Combine multiple microphones into one virtual source
• Hot-Plug — Automatically detects devices when plugged in (headless mode)
• Simple Interface — Click to select devices, then create routes
• PipeWire/PulseAudio — Works with modern Linux audio stacks

Use Cases

• 🎧 Two people listening to the same audio with their own earbuds
• 🎤 Both users' mics mixed for remote calls
• 💻 Pair programming with shared audio
• 🎬 Shared movie watching with individual volume control

Installation

Requirements

• GTK 4.0, libadwaita 1.x, GJS
• PulseAudio or PipeWire (with PulseAudio compatibility)

# Arch
sudo pacman -S gtk4 libadwaita gjs

# Ubuntu/Debian
sudo apt install gjs libgtk-4-1 libadwaita-1-0 gir1.2-gtk-4.0 gir1.2-adw-1

# Fedora
sudo dnf install gtk4 libadwaita gjs

Usage

Desktop Mode (GUI)

./lichen.js

1. Select 2+ output devices → "Create Combined Output"
2. Select 2+ input devices → "Create Mixed Input"
3. App automatically sets combined devices as default

Headless Mode (Raspberry Pi)

For running on a headless Pi as a dedicated audio mixer:

make install    # Deploy to Pi
make setup      # Configure bridge adapter
make start      # Start service
make logs       # Stream logs (Ctrl+C to exit)

See RASPI-INSTALL.md for full Raspberry Pi setup.

How It Works

Lichen uses PulseAudio/PipeWire modules:

• Combined Sink (module-combine-sink) — Virtual output mirroring to multiple physical outputs
• Mixed Source (module-null-sink + module-loopback) — Virtual input combining multiple physical inputs

Keyboard Shortcuts

Shortcut	Action
Ctrl+R	Refresh device list
Ctrl+Q	Quit

License

MIT