When building your own dream PC, or even just one that you are able to afford, one item that sometimes gets overlooked is the sound card. We've become so accustomed to having our trusty SoundBlaster 16s and such that we don't always consider that better audio is available!
Times have changed, and just like graphics cards riding on the AGP bus, soundcards have become accustomed to riding the PCI bus. So what do you get when you upgrade to a PCI soundcard? Well, first, you get rid of the reliance on the ISA bus, which is horridly slow. Second, you are able to have more streams of audio going at once because of the newfound bandwidth. Third, and what comes close to my heart, you are able to achieve real 3D audio on your PC. So now you are saying, "Ok, so I am going to buy a new soundcard, what should I look for?" and that is where this guide steps in.
A few things have changed in the recent history of the soundcard that should be taken into account when you are shopping for a new one. Most notably, the PC9x specification or design guide. Two main hitters, Microsoft and Cirrus Logic, brought about this design guide for the audio realm so that hardware designers and manufacturers would have consistent standards to design to. Here are the actual specs that a manufacturer has to abide by to get the PC9x certification - and this is the Cirrus Logic paper describing the audio tests themselves.
Both are good reads if you are into the tech stuff, although some concepts might be a little more than you want to know - so here are some basic definitions to help you unravel all those figures on the spec sheet or box: