Here’s what I have posted before for 5.1 troubleshooting:
First, ensure all speakers in your 5.1 setup are connected.
The settings in BRINK inherit exactly from the settings in your Control Panel. Other games use a different API to set up the sound, so will behave independent of your Control Panel settings.
To set up your audio in BRINK, please read the following steps:
For Windows XP / Windows Vista
[ol]
[li]Quit Brink
[/li][li]Go to Control Panel -> Sound -> Playback
[/li][li]Set your preferred playback device as the default
[/li][li]Click Configure and choose your speaker configuration
[/li][li]Click Test and verify that the device you intend to work with Brink is working as expected
[/li][li]If it doesn’t work as expected in the Control Panel, it won’t work as expected in Brink
[/li][li]Once your devices are working as intended, boot Brink
[/li][/ol]
Brink should mimic exactly the settings in Control Panel
For Windows 7
[ol]
[li]Quit Brink
[/li][li]Go to Control Panel -> Sound -> Playback
[/li][li]Set your preferred playback device as the default
[/li][li]Click Configure and choose your speaker configuration
[/li][li]Click Test and verify that the device you intend to work with Brink is working as expected
[/li][li]If it doesn’t work as expected in the Control Panel, it won’t work as expected in Brink
[/li][li]Go to Control Panel -> Sound -> Playback
[/li][li]Set your preferred communications device as the default
[/li][li]Click Configure and choose your speaker configuration
[/li][li]Click Test and verify that the device you intend to work with Brink is working as expected
[/li][li]If it doesn’t work as expected in the Control Panel, it won’t work as expected in Brink.
[/li][li]Once your devices are working as intended, boot Brink
[/li][/ol]
Brink should mimic exactly the settings in Control Panel
Everything else can be done from the in-game menus.
I’m sorry I can’t help more but right now my focus is on investigating reports where users can’t play the game, etc.