someone31988

You have computer specific 5.1 speakers, so rather than using an optical cable, just use the triple 3.5 mm cable that came with the Z906 and connect it to your computer's onboard sound output. Match pink to pink (surround left and right), black to black (center and subwoofer), and green to green (front left and right). Your computer will then decode any 5.1 channel audio tracks regardless if it's DTS, Dolby Digital, 5.1 channel FLAC, Dolby TrueHD, DTS-HD Master Audio, etc. EDIT: I forgot to mention that you may need to specify in the Windows audio control panel that you are using a 5.1 configuration rather than stereo, though. However, I've noticed that the newer versions of Windows 10 seem to auto detect this, and I can't find those old built-in controls anymore. If you have the Realtek config manager installed or something similar, you can likely change this setting there, too.