I have five speakers and one subwoofer connected to a Samsung HT-Z310 DVD-player, and then connect that to my MacBook using AUX 2.
(I have no idea what AUX 2 is, but that's what the tiny display on the DVD-player says.)
The problem is that the Mac only plays stereo on them.
When I open Realtek HD Audio Manager, in the "Speakers" tab, and the "Speaker Configuration" subtab, "Speaker Configuration" is set to "Stereo" by default. And it's grayed out, so I can't change it.
Further than that, I only have two options: "Full-range Speakers" - "Front left and right" and "Headphone Virtualization".
I have also tried "Control Panel", "Hardware and Sound", "Sound", marking the speakers and clicking "Configure", but the only option displayed in the list is "Stereo".
I have no idea what's wrong. The rear speakers work, but play the same sound as the front speakers.