Using the Internal Microphone
Out of the box, you can use the internal microphone on your MacBook Pro to create the visuals. There are a few benefits to doing this:
- Slightly more efficient on the CPU
- Don’t have to deal with aggregate output device
- You can have fun with your friends screaming at the touch bar
The visuals using the internal microphone will be slightly less accurate than using the system audio, but it will still definitely get the job done.
Increasing Visual Height
If the visuals appear to be low using the microphone, you can go into System Preferences -> Sound -> Input: select the microphone and then increase the input level to the maximum.