Can anyone be a big help, at all? Just got my new pc with Windows 8.1, and have 5.1 speakers, and the front speakers all work, including the bass, but there's nothing coming out the rear ones. The jacks are obviously in the right place as the front wouldn't be right if they wasn't. Also, I noticed adjust the bass and treble properties doesn't have an effect neither. Any advice, no idea what to do? Thanks.