I listen to music using Rhythmbox. Meanwhile I browse web with Firefox. When a page is loading, I switch tabs or I scroll up-down a site (and sometimes randomly), terrible "cracks" are audible, and I am extremely irritated by them, as they totally mess up the music. Any solutions, or tips how to troubleshoot these sound artifacts?
Audigy 2 user here.
With PulseAudio, I have to lower the Wave volume from my mixer (alsamixer) to remove static / cracking noises. (This took me a stupidly long time to figure out.)
This disables sound from Flash videos and the like, but mpd, VLC, etc. still work as they should without any cracking or popping (they are configured to interface with PulseAudio). That said, when I have to play a Flash video, I turn the Wave volume back up.
mplayer may have the same problem because it tries to use OSS or ALSA instead of PulseAudio (you should be able to configure it differently).
Is this an old computer? I had a really weird problem with a desktop machine a few years ago, when I could hear the network traffic in my speakers (I'm not kidding). After a long research I found out that the problem was caused by the fact that the sound card and the network card shared the same IRQ.