Intel gave integrated audio a bad name with the Audio Codec '97 (AC97) implementation it installed in its chipsets, starting with the i810. NVIDIA's nForce2 audio processor is now light years ahead of AC97--and, in a few respects, ahead of the latest Sound Blasters, too. But, this isn't a story about integrated audio. We're here to discuss external soundboards.

            External sound adapters are products that, at the very least, move all of your audio ports to an external box that cables back to the PC. In addition, most include embedded circuitry designed to take over work normally done inside the computer, even including some functions the PC may not handle, such as 5.1 surround sound decoding.

            Why would you want an external adapter? For starters, it's the only way you're going to get respectable audio performance out of a notebook. Even if your portable has output jacks for front and rear channels, it isn't able to handle the center/subwoofer. Does its audio chip even support 5.1 decoding? Probably not.

            If you've ever been down on your hands and knees under your desk, you know that fumbling through the dark and dust in search of the right speaker or microphone jack on the back of your PC is a drag. An external audio breakout box puts nearly every audio port and jack at your fingertips, right there on the desk next to your monitor or by your elbow.

            Because most external audio adapters are USB-based, you will not only have a much easier setup than installing an internal card, but you also save a motherboard slot and most likely have both PC and Mac compatibility. If you have more than one PC, including a laptop, just move the box and plug it into the new machine. Ten seconds and you've installed high-performance surround sound support on your new computer.

Performance Issues

Not everything is perfect with external audio, though. According to Micah Stroud, NVIDIA's senior product manager for audio, external audio is inherently more expensive because of higher materials cost, not the least of which is memory. More critical than price, however, is the problem of latency that results from having to send raw audio data out over the USB bus for external processing.

            This isn't to say that external sound doesn't have its own counter-arguments. From a sonic fidelity perspective, having sound processed outside of the PC frees the audio channel from much of the electromagnetic interference that drives, power supplies, and other PC components typically inject into the audio stream, interference that a good set of speakers will output as noise. Of course, interference can still creep into the wires running between the sound adapter and the speakers, but using a digital connection between these two helps mitigate the noise risks.

            Then there is the greater diversity of ports and features, more than you could possibly cram into any internal sound card, even with a dongle or two. External adapters feature everything from conventional phone jacks to RCA, optical, MIDI, and knobs for volume and input levels--a vast improvement on digging through onscreen software for the same controls. Moreover, with external RCA inputs, you can plug in your old LP player or tape deck for easy analog-to-digital ripping without the need for costly and inconvenient adapter cords.

            The sound processing that happens inside the external audio box is processing that isn't being shouldered by the system CPU. NVIDIA's nForce family of chipsets has dedicated digital signal processors (DSPs) designed to handle this processing, but most integrated audio solutions do not. Especially in older, slower systems, or even current system bogged down with a heavy multitasking load, having an external location where effects, decoding, and other audio functions are handled can offer a slight improvement to overall system performance and a huge boost to delivering a flawless audio stream.