How to Create a Multi-Output Device on Mac

Essential answer

You create a macOS multi-output device in Audio MIDI Setup. This combines two or more output devices into one selectable audio destination, so sound can play to them at the same time. A common reason is sending computer audio to both wired speakers and another output, but the multi-output device is specifically for audio output, not for selecting a webcam or microphone input.

Before you start

Connect and turn on the physical output devices you want to include, such as speakers, headphones, an HDMI display, or a USB audio interface. A device that is not connected to the Mac will not be available to add.

Create a multi-output device

• Open Audio MIDI Setup, which is in the Utilities folder inside Applications.
• If the Audio Devices window is not already visible, choose Show Audio Devices from the Window menu.
• Click the add button at the bottom-left of the Audio Devices window, then choose Create Multi-Output Device.
• In the device list, select the new Multi-Output Device.
• In the right-hand panel, tick Use for each output device you want to include.
• Optionally choose a primary device for timing from the Master Device menu.
• Rename the multi-output device by double-clicking its name if you want an easier label to recognise.

Check that it is ready

After creating it, go to System Settings and choose Sound, or open an app that supports choosing an output. The new multi-output device should appear in the audio output list. Select it, then play audio to confirm that all included devices are producing sound.

What this does not control

A multi-output device manages audio output only. It does not select a webcam for video capture, choose a microphone input, grant microphone or camera permission, or combine multiple microphones into a single input. For a microphone, use the input list in your app or in System Settings under Sound and Input instead.