Finally resolved the audio problem with KM Player

I always got fustrated by KMPlayer's audio as the 5.1 source of some of the videos doesn't work well with my stereo speaking. Today I found out the answer.

You either follow the instructions in here, or you can do the following:

• In KMPlayer, select preference.
• Select the node: Filter Control - Decoder Usage - External Audio Decoder.
• Select the button [C] next to the AC3 audio. The AC3 audio window will pop up.
• In [Main] tab, select "2/0 - stereo" as Output format.
  

That's all.