DEPRECATED

See repository here for a Unity 2019 sample that includes Loopback and Microphone as well as a VFX Graph example:

https://github.com/hallidev/UnityWasapiAudio

UnityWASAPILoopbackAudio

A barebones example of WASAPI Loopback Audio in Unity using CSCore

Check out CSCore: https://github.com/filoe/cscore

Instructions:

1: Clone / download

2: Open in Unity

3: IMPORTANT! If you are going to be making a build using this, you need to go to Edit -> Project Settings -> Player -> Api Compatibility Level and set it to ".NET 4.x". Otherwise you will get a kernel exception upon trying to run Unity Player.

4: Play some music on your computer

5: Bang that "Play" button

That's it!

You won't see the bar analyzer until you hit Play - it's instantiated at runtime.