Aggregate Device (In Depth)

# # What is an Aggregate Device?

An Aggregate Device is a virtual audio device in macOS that combines two or more audio devices into a single input. This allows applications that can normally select only one audio device to access multiple devices simultaneously.

# # Common Uses for Aggregate Devices

Aggregate Devices are useful in several scenarios, including:

• • • Recording your microphone and system audio at the same time.
• • • Combining multiple microphones into a single recording source.
• • • Using several audio interfaces simultaneously.
• • • Capturing audio from virtual devices such as BlackHole alongside physical audio hardware.
• • • Streaming or podcasting setups that require multiple audio sources to be available within a single application.
• • • DAWs or recording software that only allow one audio input device to be selected at a time.

# # Example Setup: Recording Your Microphone and System Audio into Audacity

In this example, we will record both:

• • • Your MacBook's built-in microphone
• • • Your system audio routed through BlackHole

These sources will be combined into a single Aggregate Device and recorded in Audacity.

## ## Easy Step-by-Step Instructions for Recording with an Aggregate Device

# # 1: Open Audio MIDI Setup.

Launch Audio MIDI Setup from Applications.