|Have you verified that the cord/adapter you are using actually "works" for both left and right? Since surround systems have varying input requirments, its possible to hookup a 5.1 system using a stereo jack/cord. It depends on the inputs on your sustem.|
I have a 5.1 sysem that outputs from my PC as left/right stereo, but the surround processing is more/less done by the software being used to play my media. Hope that helps.