Hi, I know that there are a bunch of posts on this subject already. I have ready many of them and I still can't figure out what it is I need. I have tried several things with no success. There seems to be many variations so I thought I would post specifically what mine is. I have TurtleBeach X41 headset. If possible, I would like to use them for surround sound on my 2011 27" iMac. For games specifically. I have gotten surround sound for other things, but not games. Even more specific for Battlefield 3. I have the toslink adapter so i can run the optical out to my X41 headset. I can even "test" the 5.1 surround sound in windows and it works, but when i boot up Battlefield 3, I can only select stero options. I have read some things about Dolby Digital Live, AC3 Fitlers, but everyone had different configurations on there iMacs. Does anyone have any ideas/thoughts. Is it even possible what I am trying to do? I really appreciate the help. I can provide any other information as needed, just ask me. Thanks!