The Sound Card: A Microchip Miracle?

Sound like just another inflated sales pitch? Not this time. Though perhaps not deserving of the word "miracle," the average computer sound card is an amazingly versatile product. And unless you're planning to carve out your niche in silent videos, a sound card is a must-have for PC-based videographers. It comes as a surprise to many that the majority of nonlinear editing cards, especially those in the under-$1000 price range, do not have sound support built in.

Sound cards are not only for nonlinear editing--even folks with the simplest "two-finger" editing system can use a sound card to aid in their productions. With an inexpensive sound editor (often included with the sound card), you can do almost unlimited drag-and-drop editing of sounds. The sound card's built-in synthesizer means you can create your own music or sound effects, running the card's output to a mixer or record deck. Most sound cards include a MIDI interface; with this, you can enjoy the improved sound quality of a MIDI keyboard or synthesizer for your music. With the sound card's built-in mixer, you can combine two or more external sound sources during editing.

In the next few pages, we'll explore what a sound card is, how it works, and how to pick the best type of card for your needs. We'll concentrate on those features that allow a sound card to record, play back or generate sound and music.

It's worth noting that you may not need to buy a sound card at all. If your computer is a "multimedia" model, you probably already have the ability to record and play back sound. And most Macintosh computers will also handle sound right out of the box. But that doesn't mean you can't upgrade your multimedia PC or Macintosh's sound capabilities for better performance or flexibility.

There are two main styles of audio card that PC owners will run across. General-purpose multimedia cards offer good sound quality with a wealth of features. Higher-quality audio-only cards are designed exclusively for audio recording.

Multimedia sound cards record and play back audio, but also allow you to play games, attach a joystick or control a musical-instrument digital-interface (MIDI) synthesizer. These cards are well-suited for video production, and you may find good use for their other features as well. The main drawback with many of the general-purpose cards is the limited flexibility of their audio inputs and outputs.

These cards will work as a simple audio mixer. Most offer both line and microphone inputs, the latter having a preamp to boost the level of the mike signal. With the audio mixer software provided with the card, you can blend these two inputs and send the completed mix to the card's stereo output. Most sound cards will allow you to blend in music or speech from the on-board synthesizer as well. Sound cards usually lack the inputs to do serious audio mixing, but being able to blend a few inputs may be just the ticket for some videos.

Cards designed specifically for audio recording offer excellent sound quality with few bells and whistles. The primary advantage of these cards lies in how they connect with other audio equipment. Many audio-only cards offer four or even eight individual outputs. These can make controlling your audio easier with a dedicated mixer. Some cards offer dedicated signal processing (DSP) right on the board. This allows you to alter the tone or dynamic range of your sounds. Some DSP-equipped cards allow you to add real-time effects like reverb or delay.

Regardless of what style of card you end up with, your linear- or nonlinear-editing package will most likely control it through standard software drivers. This makes it easy to integrate almost any type of sound card into your system.