I would like to override the media left and right volume setting separately as a whole.
It does not seem possible to set the left and right volume separately using AudioManager.setStreamVolume().
I noticed it is possible though to set it with MediaPlayer.setVolume() or SoundPool.play() but I would like to override the whole system media settings so the stereo balance would be kept among the different music players and applications.
I'm not really familiar with Android so I would welcome all advices, tips that could help me achieve this.
ps: I am working on Android 2.3.4. and I would not mind if this needs to go through root rights.
Left / right volume adjustment for system / user is not available in the public API. It's only only available on app level, using the methods you mentioned.
You can set the right and left volume with this 2nd and 3 parameter: SoundPool, developer.android.com
来源：https://stackoverflow.com/questions/10265933/set-media-left-right-volume-separately