The Sound Card: A Microchip Miracle? (page 3)

Synthesized Magic

Multimedia sound cards can draw on several different methods to create sounds. The first is true synthesis, where the card creates sounds from scratch. Often using a method called frequency modulation (FM), these inexpensive cards aren't very convincing when trying to simulate acoustic instruments. But for spacey, ethereal sounds and effects, they do very well.

Wavetable synthesis adds actual sound recordings (or samples) to the sound card's repertoire. Because these samples come from real instruments, wavetable sound cards achieve a much higher degree of realism. Disadvantages? They cost a bit more, primarily due to the memory required to store the samples.

Many multimedia cards offer a combination of both synthesis and sample-based sounds. These cards can generate FM sounds, sampled sounds, or mix the two together for the best of both worlds. Many sound cards allow users to attach a sample-based daughterboard, effectively upgrading a synthesis-only card to a sample-based model. Several pioneers of audio sampling (Kurzweil, Ensoniq, E-MU Systems) make such upgrade cards, and the improvement in sound quality is striking.

Another potential disadvantage of sample-based cards is that they're only as good as the sounds the manufacturer put on them to begin with. There's at least one notable exception to this, however--the Adobe Soundfonts system. Soundfonts allow you to download samples from the web or other source, storing them on the sound card. This makes the sound card somewhat obsolescence-proof, and insures that you're not locked in to the sounds your card originally came with.

Fade Out

Whether it's a multimedia Swiss-army knife or an audio-only model, a sound card packs a lot of audio power into a small package. These capabilities will only expand in the future, as sound cards deliver higher-fidelity audio, more-realistic sounds, better on-board processing and surround-sound recordings.

Learn the ins and outs of the sound card, and your videos may never sound the same aga…