MSI 955X Platinum Series User Manual page 138

W hen you are playing the first audio source (for example: use W indows
Media Player to play DVD/VCD), the output will be played from the rear panel, which
is the default setting.
Then you must to select the Realtek HD Audio front output from the
scroll list first, and use a different program to play the second audio source (for
example: use W inamp to play MP3 files). You will find that the second audio source
(MP3 music) will come out from the Line-Out audio jack of Front Panel.
Introduction to Realtek ALC 882M
7-9