MSI MS 7005 - 651M-L Motherboard - Micro ATX User Manual page 76

Using 4- or 6-Channel Audio Function
4. While you are testing the speakers in 6-Channel Mode, if the sound com-
ing from the center speaker and subwoofer is swapped, you should select
Swap Center/Subwoofer Output to readjust these two channels.
Select this function
A-9