Free Digital Audio Recording on Mac: Capture System Sound Using the BlackHole Virtual Driver

Introduction

Sometimes a game has beautiful in-game music, or you have a video with a great soundtrack. There are many reasons why you might want to record the sound playing on your Mac directly as an audio file. Here we'll show you how to do it easily and for free – and with the "Maximum" quality setting in QuickTime, even without any loss of quality.

Alternative: Hardware Cable Recording

Before we get to the elegant solution, here's a quick look at the "old school" method: you can actually run a cable from the headphone output to the microphone input. This works, but it has some disadvantages:

• Quality loss due to double conversion (Digital → Analog → Digital)
• Possible interference from the cable
• You can't hear anything during recording
• Newer Macs no longer have a separate line-in port, so you'd need a USB audio interface

Install the BlackHole Audio Driver

BlackHole is a virtual audio driver that lets you route audio between different apps on your Mac. It's free and open source, and it works perfectly for our purpose. You can download BlackHole from GitHub here.

After installing it, set the output and input to "BlackHole 2ch" in System Settings → Sound.

Recording with QuickTime Player

Open QuickTime Player and go to "File" → "New Audio Recording".

In the recording window, click the arrow next to the red record button and select "BlackHole 2ch" as the source.

When you now start recording, QuickTime records the Mac's internal audio. When you stop, you can save the recording as a file.

Monitor Audio While Recording (Optional)

So you're not "deaf" during recording, you can create a "multi-output device". This sends the audio simultaneously to BlackHole and to your speakers or headphones.

1. Open the "Audio MIDI Setup" app (in Applications → Utilities).
2. Click the plus icon at the bottom left and select "Create Multi-Output Device".
3. In the list, select your normal speakers/headphones and "BlackHole 2ch". Enable "Drift Correction" for "BlackHole 2ch".
4. Right-click the new multi-output device and select "Use This Device For Sound Output".