January 16, 2023
MacOS comes with a handy free audio utility to mix the audio of multiple microphones into a single audio device that you can use in other applications. In just a few simple steps you can set up a minimal production studio with two USB microphones and start recording your podcast, without having to invest in advanced devices like the RodeCaster Pro or other audio mixers.
Connect your microphones
Connect two or more microphones to your Mac. If you’re running out of ports, you can use a high-speed USB-c hub to connect multiple microphones to a single USB port on your Mac. Because most USB microphones draw power over the USB port, you’ll probably need a powered USB hub for a reliable connection.
Using two microphones as one device
Your Mac comes with a free app “Audio MIDI Setup”. You’ll find this app in Utilities in the Applications folder. Open the app from your Applications folder or search for Audio MIDI Setup in Spotlight.
All audio devices that are connected to your Mac are listed in the side panel, including input and output devices. Some applications also create “virtual audio devices”, which are software devices that can input or output audio. We're going to create a virtual device that combines two or more audio devices and makes them available as a single input device that you can use in Detail to record or stream.
Open the app “Audio MIDI Setup” on macOS.
Hit the plus ➕and select “Create Aggregate Device” (bottom left).
Select the microphones you want to combine with a checkmark for “Use”.
Enable “Drift Correction” for the microphones that are not set as “Clock Source”.
Record a video podcast with two USB microphones
After you’ve created an Aggregate Audio Device to combine both microphones into a single device, you can select the device in other applications on your Mac. If you select the Aggregate Audio Device as your microphone in Detail, we’ll automatically record all microphones as separate audio channels for your video podcast, and mix down the output when you export your video or clips.
Software for Røde, Elgato, or Blue microphones
USB Microphones like the Elgato WAVE 3 and Rode NT-USB or NT-USB Mini come with software to install on macOS, which gives you control over the microphone settings and creates a virtual audio device with the mixed output of your microphones. If your microphone doesn’t have any software mixer available or if you want to mix different brands of microphones, Audio Midi Setup on macOS covers the basics to start recording.