We've come a long way from the days when a basic sound card and a couple of cheap speakers were all your PC needed. With DVDs and games packing support for immersive, 360-degree audio, high-quality surround-sound support is more popular (and more necessary) than ever.

The newest computers often come with decent-quality multichannel sound hardware built into the motherboard. But if you want to get the best audio quality, you'll need to upgrade to either a high-quality internal sound card ($50 to $200) or one of the new generation of external sound processors ($100 to $150) that plug into your machine's USB port.

If you're serious about audio, figure on spending at least $150 to $400 for a top-quality set of surround speakers with subwoofer. Alternatively, you can plug the output of that new sound hardware into your existing home theater system. And if you work in an office or you don't want to disturb the household at night while you hold off alien invaders, consider investing in a good pair of headphones.

Sound systems are designated as 2.1, 4.1, 5.1, 6.1, and 7.1 (see the illustration for tips on setting them up). And games and DVD source material come with different types of surround support, with names such as Dolby Digital 5.1, DTS, and Dolby Digital EX. Most sound cards have the ability to convert standard stereo CDs or MP3 files to surround sound, letting you take advantage of your new speakers more often.

The Shopping List shows examples of products you might want to have in a first-rate PC audio setup.