Answer:STEP 1:
4 CH: Connect the front L/R channel to "Line Out", the rear L/R channel to "Line In".

6 CH: Connect the front L/R channel to "Line Out", the rear L/R channel to "Line In", and the Center/Subwoofer channel to "Mic In".



STEP 2:
After installation of C-Media Audio driver, you will find an icon "C-Media Audio configuration" on the taskbar.

STEP 3:
Click the icon, and the screen will show the current audio configuration.

Select "Output" to change your audio configuration. Select "Analog" for Output Type and choose "4 channels" / "6 channels" for your speaker configuration.

Then press "Apply" and press "Ok".