MSI 845PE Neo Series Manual page 84

Speaker Test
You can use this tab to test each connected speaker to ensure if 4- or 6-
channel audio operation works properly. If any speaker fails to make sound,
then check whether the cable is inserted firmly to the connector or replace the
bad speakers with good ones.
Front Left
Rear Left
Select this function
Select the speaker by clicking it to test its functionality. The one you
select will light up and make testing sound.
Using 2-, 4- or 6-Channel Audio Function
Center
Front Right
Rear Right
Subwoofer
A-9