Use BlackHole as a Virtual Microphone
BlackHole can be used as a virtual audio input for applications that accept microphone or audio input devices. This allows you to send audio from your Mac to applications such as Discord, Zoom, OBS, and other audio software.
Make sure BlackHole is installed on your Mac.
For this guide, we'll use BlackHole 2ch as the example.
Click here for the complete guide on how to create a Multi-Output Device.
After setting it up, your Multi-Output Device now sends audio to both BlackHole and your physical playback device.
Set the Multi-Output Device as the output device for the audio you want to route.
For example, you can select it as the output device in your DAW or set it as your Mac's system output.
Audio will now be sent to both destinations:
flowchart LR
A[Audio Source] --> B[Multi-Output Device]
B --> C[BlackHole 2ch]
B --> D[Speakers / Headphones]
This allows the receiving application to access the audio through BlackHole while you continue listening normally.
Open the application where you want to receive the audio.
Look for its Microphone, Input Device, or Audio Input settings and select:
BlackHole 2ch
For example, in OBS, you can add an Audio Input Capture source and select BlackHole 2ch.
The application will now receive the audio being sent through BlackHole.
Suppose you want to send audio from Logic Pro to Discord while still hearing Logic through your headphones.
Your setup would be:
flowchart LR
A[Logic Pro] --> B[Multi-Output Device]
B --> C[BlackHole 2ch]
B --> D[Headphones]
C --> E[Discord]
Logic Pro sends its output to the Multi-Output Device. The Multi-Output Device duplicates that output to both BlackHole and your headphones.
Discord then uses BlackHole as its input and receives the audio from Logic.
The same setup can be used to route your Mac's system audio.
Set the Multi-Output Device as your Mac's sound output. Your system audio will then be sent to both your normal playback device and BlackHole.
You can select BlackHole as the input device in the application receiving the audio.
This can be useful for sending:
- Music or streaming audio
- Web browser audio
- Videos
- System sounds
- Audio from other applications
A Multi-Output Device only handles outputs. It does not combine your physical microphone with BlackHole.
If you need to send both your microphone and BlackHole audio to the same application, you can create an Aggregate Device containing your microphone and BlackHole.
Note: This is not necessary when your microphone is already being recorded through your DAW. In that case, the DAW can send both the microphone and other audio through the Multi-Output Device and into BlackHole.
For example:
flowchart TD
A[Microphone] --> C[Aggregate Device]
B[BlackHole] --> C
C --> D[Receiving Application]
See Aggregate Device (In Depth) for more information.
Make sure:
- Your Multi-Output Device contains BlackHole 2ch.
- The source application is using the Multi-Output Device as its output.
- The receiving application is using BlackHole 2ch as its input.
- Audio is playing through the source application.
Check that your speakers or headphones are included in the Multi-Output Device alongside BlackHole.
BlackHole does not provide physical audio playback by itself. The purpose of the Multi-Output Device is to send the audio to both BlackHole and your chosen playback device.
Make sure BlackHole is installed correctly and restart the receiving application.
You can also verify that BlackHole appears in Audio MIDI Setup.
When using multiple audio devices, differences in their clocks can cause synchronization issues. Check your Multi-Output Device configuration and make sure the appropriate device is selected as the primary device.