Does it sound like sound tearing? Like there's static? There's a few things that can cause that, if the pc is turned down to, for example, 20% volume, and whatever powers your speakers (I.e dvd player, stereo receiver) is turned up to 100%, that will cause what I call sound tearing. Basically you need to turn the pc up higher and the dvd player/stereo receiver lower, typically I leave the PC at 100% and the receiver at whatever I want to listen to. Whatever is directly feeding power to the speakers should determine how loud it is, not whatever is giving the audio.
The other option is that you're blowing your speakers out from having them turn't up too often (lots of loud music constantly).
I am using a digital optical cable so that is giving the sound ?? EDIT: that sounded stupid but I don't think it is getting enough power??? I guess....,
As long as your speakers are properly externally powered, there shouldn't be a problem, make sure your audio drivers are up to date or maybe try a different output method. (such as a the more traditional 3.5mm aux cable).
I have the same problem but my speakers only cut out when i go beyond 70 volume (that's way too loud so it's fine)
I beleive it's because i have too many speakers laced to other wires lel, there's a wattage light flashing on my hub so it's prolly gonna explode.