get creative with ambisonic surround sound
How to listen on an AV receiver
The 'AV receiver' stream is intended to be streamed digitally to an AV receiver. This allows the AV receiver to act as a digital to analog converter which can provide superior audio quality.
Unfortunately (at the time of writing) this wont work out of the box. To get this to work on OSX, you can follow the instructions here, or here.
Getting 'digital pass-through' working on Windows will depend on the sound card you are equipped with. Typically, however, Windows machines will be equipped with 5.1 sound cards which will avert the need to use an AV receiver.