Turtle beach PX5 optical out
Trying to get my turtle beach PX5 headphones to work with my MacBook Pro via the optical out port so I can use them for gaming and films with surround sound but I don't seem to be able to get the headphones to pick up anything. I have them connected as such PX5 -> reciever -> optical cable -> spidf headphone jack style adaptor -> MBP.
They work over bluetooth and I have used the optical port in the past and can see the red light so presume it is working ok and I can use the headphones over optical with my ps3. Does the MBP use a strange optical output or codec that the headphones can't pick up?
Tried everything I can think of such as manually selecting the headset in sys prefs and in Audio MIDI setup, which only shows 2 speakers as stereo despite the PX5 being capable of 5.1 and am now very confused.
Please help!
Thanks
MacBook Pro, OS X Mountain Lion (10.8.1)