The soundcard is the single-most critical component in the DAW system. To be effective it must be a full-duplex soundcard. Full-duplex means that you can record a track at the same time you listen to a previously recorded track. It is the same concept as sound-on-sound recording on an analog tape recorder. Many multi-media soundcards such as the Soundblaster Live, Monster, Turtle Beach, and other Soundblaster-compatible lines are capable of full-duplex recording. Soundcards dedicated to recording, such as the M Audio/Midiman Delta Series, the Echo line, Mark of the Unicorn and Yamaha are available but are significantly more expensive.
Any of the above soundcards are capable of recording very good quality audio, some better than others. It is important to realize that not all soundcards are created equal when it comes to digital recording. The degree to which the card is specialized for recording may have an impact on the quality of the recording. A critical element in achieving recording quality is how accurately a cards A/D and D/A converters record and playback audio. Another critical issue is how many tracks a soundcard can record and playback at once.
- For a quick overview of soundcard features, I have constructed a soundcard table that contains essential features and links back to the manufacturer's site.
One way to compare soundcards is to review the specifications published by the manufacturer. You should be cautious, some specifications are overstated as they are generated in a perfect lab environment. Moreover, specifications are not necessarily the best and final criteria you should use in making a purchase decision.
A couple of things are clear. You should get as quiet a soundcard as you can. The lower the noise floor is for your soundcard, the better. This is how quiet your card is itself, when nothing is being recorded. Therefore, you should strive to get a card with a high signal-to-noise ratio. Signal-to-noise ratios measure how effective the card is in capturing the music without introducing its own noise.
Consult with your music store expert, your friends, search the web for users forums, and lastly and most importantly, use your ears. You will find that soundcards with the exact same specifications sound different to you. You may find that a soundcard with technically inferior specifications actually sounds better to you. At some point, a cards technical superiority may not be discernible to the human ear. It is often a question of taste over specifications.