Connecting Multiple USB Microphones on a Mac (probably for Podcasting)

This was surprisingly hard to find, but the answer was straightforward in the end. I’m using Adobe Audition for this example, but the same solution works for GarageBand or any other audio editing app (at least, it should).

The Problem

If you’ve ever used an audio interface before then you’re used to being able to select multiple inputs from the interface, which is necessary for multitrack recording. That’s because the audio interface is providing the system clock to be the digital sample rate driver. Connecting multiple microphones to a USB hub will only allow you select one of those microphones to be the master clock, which causes a problem. So no matter how many USB mics you connect, you can only use one in your multitrack software. Bummer.

The Solution

Apple already has a built-in solution for this. In your Applications/Utilities folder is an app called Audio Midi Setup, and it’s got a cool little feature in it.

I’ve never needed this software ever, up until this multiple USB mic thing

In the bottom left of the Audio Midi Setup app is a little plus icon: click it and select “Create Aggregate Device”.

Click that one. You’re going to aggregate your USB mics into one device.

In my case, I had three USB Blue Yeti microphones I wanted to work with. Here, you can see I’ve selected both channels from each microphone.

This is where the magic happens. Now all my mics are grouped into one device.

In Adobe Audition (or equivalent), select your default input to be the “Aggregate Device” now showing up as one of your inputs.

Now you can select the stereo (or mono) inputs for each of your tracks. You’re done!

That’s it! It’s so simple (if you know where to start).