5.1 Surround not working, only stereo

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Hello guys,

 

DayZ SA is not using my surround system, only left and right speakers. I only have stereo while i should have 5.1 surround.

I own a Logitech 5.1 Speaker system (NO headphones) and i am using it via onboard soundcard and Realtek drivers.Ususally it works just fine, cod, battlefield, even racing games are able to use its potential. No problems with other games. Ive read in forums that other people using this kind of setup do not have any problems.
What can i try to make it work? no "buy a soundcard"-b.s. please