First you will need to create a new INPUT and OUTPUT

Open the Audio Midi Setup: Applications/Utilities/Audio Midi Setup

This will create the custom OUTPUT

Click on the PLUS sign and then choose Create Multi-Output Device

Check the box for Built-In Output

Then check the box for BlackHole 16ch

note: it is important that you first check the box for Built-in Output

before you check the box for BlackHole 16ch. Built-in Output should

be first in the list

Then check the box for Drift Correction for BlackHole 16ch

Double check your settings and make sure they look exactly like you

see them in the screenshot.

This will create the custom INPUT

Click on the PLUS sign and then choose Create Aggregate Device

Check the box for BlackHole 16ch

Then check the box for your Microphone

In this example the microphone is a Rode VideoMic NTG.

If you use an external microphone choose it. If you use a

laptop the microphone will be the Built-in Microphone. If you

use an external webcam the microphone on the webcam will

also be an option listed.

Check the box for Drift Correction for the microphone

Double check your settings and make sure they look exactly like you

see them in the screenshot

If you want, you can rename the default names (Multi-Output Device & Aggregate Device)

by clicking on the names.

In this example they were renamed as Built-in Output + BlackHole and BlackHole Input

And finally the last step is to choose this new INPUT and OUTPUT in the SOUND settings under SYSTEM PREFERENCES.

Under the OUTPUT tab → choose the newly created output

(in this example it is Built-In + BlackHole)

Under the INPUT tab → choose the newly created input

(in this example it is BlackHole Input)