MicMixer Soundboard 🎵

Real-time soundboard with microphone mixing for macOS

MicMixer lets you play sound effects that mix seamlessly with your microphone input for Discord, Zoom, OBS, and other streaming/communication apps. Perfect for streamers, podcasters, and anyone who wants to add audio flair to their calls.

Features

• Real-time microphone mixing with sound effects
• Independent volume controls for mic and sounds
• Toggle sounds on/off by clicking (click to play, click again to stop)
• Simple MP3 file management (just drop files in the sounds/ folder)
• Clean, modern UI with visual feedback
• Low latency audio processing

🔧 Installation

1. Install Dependencies

npm install

2. Install BlackHole Audio Driver

BlackHole is a virtual audio driver that routes audio between applications.

brew install blackhole-2ch

Or download manually: BlackHole Releases

⚠️ Important: Reboot your Mac after installing BlackHole.

3. Configure Audio Routing

Create Multi-Output Device

1. Open Audio MIDI Setup (Spotlight → "Audio MIDI Setup")
2. Click the + button (bottom left) → Create Multi-Output Device
3. Check both:
   • Your speakers/headphones
   • BlackHole 2ch
4. Right-click the Multi-Output Device → Use This Device For Sound Output

Configure Your Communication App

In Discord, Zoom, OBS, or your streaming software:

• Set Input Device to BlackHole 2ch

Now your app will receive both your microphone and soundboard audio!

Usage

Start the App

npm start

Add Your Sounds

1. Place MP3 files in the sounds/ folder
2. Restart the app or it will auto-load them
3. Sound buttons will appear with the filename (without .mp3)

Using the Soundboard

1. Select your microphone from the dropdown
2. Adjust volumes using the sliders
3. Click a sound to play it
4. Click again to stop it
5. Your communication app will receive the mixed audio!

Controls

Control	Description
Microphone Select	Choose your physical microphone
Mic Volume	Adjust microphone input level (0-100%)
Sound Volume	Adjust soundboard output level (0-100%)
Sound Buttons	Click to play/stop sounds

🔊 How It Works

Your Mic ──┐
           ├──> MicMixer ──> Multi-Output ──┬──> Your Speakers
 Sounds ───┘                                  └──> BlackHole ──> Discord/Zoom/OBS

1. MicMixer captures your microphone and mixes it with sound effects
2. Multi-Output Device sends audio to both your speakers and BlackHole
3. BlackHole acts as a virtual input for other applications
4. Your apps receive the mixed audio stream

Development

Build

npm run build

This creates a distributable .dmg file in the dist/ folder.

Tech Stack

• Electron - Desktop app framework
• Web Audio API - Real-time audio processing
• Node.js - File system operations

Adding Custom Sounds

Simply drop .mp3 files into the sounds/ folder:

cp my-sound.mp3 sounds/

Restart the app and your sound will appear as a button.

⚠️ Troubleshooting

I don't hear any sound

• Make sure the Multi-Output Device is set as your system output
• Check that both your speakers and BlackHole are checked in the Multi-Output Device

I can't see BlackHole in Audio MIDI Setup

• Reboot your Mac after installing BlackHole
• Reinstall BlackHole: brew reinstall blackhole-2ch

My communication app doesn't receive audio

• Make sure the app's input is set to BlackHole 2ch
• Try restarting the communication app

I hear myself (echo)

• This is normal through your speakers
• Enable echo cancellation in your communication app
• Or use headphones

📄 License

MIT License - feel free to use, modify, and distribute.

🤝 Contributing

Contributions welcome! Feel free to open issues or submit pull requests.

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by Elioflex

Perfect for streamers, podcasters, and anyone who wants to spice up their audio.