How to Control Mac Audio Per App with External Monitor (3 Working Solutions)

The External Monitor Audio Problem

When you connect an external monitor to your Mac, you suddenly have multiple audio outputs: your Mac's built-in speakers, your headphones, and possibly audio through the monitor itself. But macOS treats audio as all-or-nothing — change the system output and every app follows along.

This creates frustrating scenarios: you want your music playing through your nice speakers while video calls go to your headset, or you want system sounds on your Mac while your external monitor handles media audio. Unfortunately, macOS doesn't include a built-in volume mixer like Windows has had since 2007.

Why macOS Audio Control Is Limited

macOS was designed with simplicity in mind. Apple assumes most users want all audio going to one output device. When you change your audio output in System Settings, every app immediately switches over.

This approach works fine for basic setups, but falls apart when you're juggling multiple audio sources with an external monitor setup. You end up constantly switching the system audio output or adjusting app volumes that affect everything at once.

Solution 1: Use Audio MIDI Setup (Built-in, Limited)

macOS includes Audio MIDI Setup for basic audio routing, though it's not particularly user-friendly.

Steps:

1. Open Applications > Utilities > Audio MIDI Setup
2. Click the + button and select Create Multi-Output Device
3. Check the audio devices you want to combine
4. Set this as your system output in System Settings > Sound

This creates a combined output that sends audio to multiple destinations simultaneously. However, you still can't control individual apps — everything goes everywhere.

Limitations: No per-app control, no volume adjustment per output, can cause audio sync issues.

Solution 2: Use Third-Party Per-App Audio Control

The most effective solution is dedicated per-app audio software that gives you the granular control macOS lacks.

What you get:

• Route individual apps to different outputs (Spotify to speakers, Zoom to headset)
• Adjust volume per app from 0-200%
• Mute specific apps without affecting others
• Save audio profiles for different setups

Apps like Soundish provide this functionality at a fraction of the cost of professional audio tools. You can set your music app to always use your good speakers while routing communication apps to your headset, regardless of what your system audio output is set to.

How it works:

1. Install the per-app audio controller
2. Grant the required audio permissions
3. Set individual apps to use specific outputs
4. Adjust volumes independently
5. Save the configuration as a profile

Solution 3: Smart Use of Built-in App Settings

Some apps have their own audio output settings that bypass the system default.

Apps with built-in audio routing:

• VLC Media Player: Preferences > Audio > Output module
• Zoom: Settings > Audio > Speaker
• Discord: Settings > Voice & Video > Output Device
• Spotify: Settings > Playback > Audio Quality (limited options)

Steps:

1. Check each app's audio/preferences settings
2. Look for "Audio Device," "Output," or "Playback Device" options
3. Set different apps to different outputs manually
4. Test the configuration

Limitations: Only works for apps that include these settings, requires manual setup per app, settings can reset after updates.

Best Setup for External Monitor Audio

For the most reliable external monitor audio setup:

Hardware connection:

• Use USB-C/Thunderbolt for digital audio when possible
• HDMI audio works but can have compatibility issues with some monitors
• Keep a good USB headset as your "communication" device

Software configuration:

1. Set your system default to your most-used output (probably speakers)
2. Use per-app audio control for exceptions
3. Create profiles for "Work" (calls to headset) and "Media" (entertainment to speakers)
4. Test the setup with your most-used apps

Why This Matters for Productivity

Proper audio routing isn't just about convenience — it's about maintaining focus. When you're deep in work and a notification blasts through your good speakers instead of your headset, it breaks concentration. When your music cuts out because you joined a video call, your workflow suffers.

Having granular control over where each app's audio goes means you can create an audio environment that supports your work instead of disrupting it.

The Bottom Line

While macOS doesn't include a proper volume mixer, you're not stuck with all-or-nothing audio control. Whether you use the built-in Audio MIDI Setup for basic needs, configure individual apps manually, or invest in dedicated per-app audio software, you can achieve the granular control that makes external monitor setups actually productive.

The key is finding the approach that matches your technical comfort level and how much control you actually need. For most people juggling work calls and media with an external monitor, dedicated per-app audio control is worth the small investment in time and money.