Usually your soundcard control panel is the place to adjust those settings. The control panel for a soundcard will override settings in Windows. If your soundcard does not have a control panel (like some older soundcards or AC97), then just select Quadraphonic or 4 speaker. There is no option for 4.1, because there are no 4 speaker systems with a seperate LFE (Low frequency Effects) connector, bass is directed via the speaker systems crossover.
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