in some cases, the simple windows troubleshooting system may partially fix some of the issues, but don't count on it. In conclusion, in most cases the OS is at fault directly for the major sound issues that are very hard to track/fix. Improvisations like disabling all effects will have bad consequences, like lower volume or even undistinguishable audio. Disabling specific things like Dolby, DTS or EAX may partially make things better. You could try updating the audio device driver. Use Peace Equalizer interface for Equalizer APO. Generally, sound is harder to tweak assuming it functions relatively correctly initially. A USB speaker is handy if you move around a lot but depending on your usage you may have something that will sound nice and just need a cable. Issues like auto-volume reduction are still unfixed practically. But there are way more functionality problems. In the newer 8.X and 10 versions, it's even a worse quality (but not that of a big decrease like from XP to Vista/7). Even good tweakers like SRS lost a lot of possibilities. If sound could be considered quite of good quality in XP, in Vista and 7 it lost a lot of quality due to the multiple OS layers interfering with the actual sound card functionality.
Overall sound quality and functionality decreased with each major windows version since XP.
