Originally Posted by cadobhuk
Wait,so I should keep the software volume on max the whole time?
Yes, that's right. Changing the volume on the computer uses digital volume control, which degrades quality. If you take a 16 bit sound sample and drop the volume to 50%, it becomes a 15 bit sound sample. At 25% volume it becomes 14 bit and so on. For non-power-of-two volume drops, it gets even worse because you also get additional aliasing from errors in the maths.
Analogue volume controls, such as the controls built in to your amp, don't have these problems.
For ASIO/kernel streaming, volume should always be 100%. In fact, the Winamp KS plugin has an option to disable volume control built in. Even for DVDs, it's best to have the volume at 100% and use your amp controls.