Things You'll Need
Instructions
Connect the digital audio output connector on the Advanced AV Pack, High Definition AV Pack or third-party AV pack to the AV port on the back of your Xbox console.
Connect one end of the optical digital audio cable to the digital audio output on the AV pack.
Connect the other end of the optical digital audio cable to your receiver's available optical digital input connection.
Turn on your Xbox, making sure there is not a disk in the drive.
From the Xbox Dashboard, select the "Settings" option.
Select "Audio." You will see an option to select "Dolby Digital."
Choose "Dolby Digital," answering "Yes" to the prompt asking whether your television supports Dolby Digital. The screen will then show that Dolby Digital is enabled. Your Xbox will now be enabled for surround sound.