September 15, 2000

Cross breeds
Audio devices mate PC and hi-fi

Digital audio is advancing by leaps and bounds—out of the PC and into your living room. A number of companies have intriguing product concepts that merge computer and consumer-electronics technologies to bring digital audio streams into the living room. As you might guess, some make more sense than others.

Micronas Semiconductor has released a reference design called AudioBox, which aims to bridge the computer and consumer worlds. Based around the company's UAC 3552 USB Audio DAC, AudioBox is meant to give system companies a jumpstart in bringing a PC to living-room bridge product to market.

AudioBox-based products will connect to a PC via the USB port, and rely on the PC processor to handle music decoding tasks, thereby minimizing the cost of the music appliance. This reliance on the PC makes the AudioBox design inherently upgradeable. The design also leverages the PC hard disk for storage, again minimizing the cost of a stand-alone audio appliance based on the design.

The benefits of the AudioBox concept also include a user interface that allows consumers to select music and programming without dealing with sometimes-cumbersome PC software. Instead, the consumer experiences a consumer-electronics style interface consistent with other living-room gear. The AudioBox output can connect directly to speakers or to an AV receiver or bookshelf stereo.

The UAC 3552A controller integrates a DSP (digital signal processor), EEPROM (electrically erasable programmable read-only memory), a DAC (digital-to-analog converter), an amplifier, and a USB controller—basically eradicating the need for a sound card. The company claims the device can deliver music in MP3 and other formats at near-CD quality. In addition to handling most compressed file types, including MP3, AAC, WMA, and Real Audio, it can also play other streaming Internet content, such as live radio broadcasts.

Manufacturers can incorporate the technology into a standalone device like the Audiobox design, says Kai Scheffer, multimedia products specialist for Micronas. More ideally, the UAC 3552A controllers can be placed directly inside stereo equipment, dissolving the need for a separate box and jumbled wires. The technology uses approximately 8 to 16 Mbytes of your PC's memory to function, says Rainer Hoffmann, Micronas' general manager. According to Hoffman, one person can continue using the PC, without affecting the AudioBox operation.

Not so fast

Unfortunately, operating an AudioBox-like product may still not be simple enough for mainstream consumers. For starters, consumers will need a broadband DSL or cable modem connection to the Internet to access live audio. But they would need that anyway, Hoffmann argues, in order to stream content to their PCs.

However, even with a broadband connection in the picture, the consumer still must get digital tunes onto the PC in the first place, either via downloading them or "ripping" them from audio CDs.

The biggest impediment to the AudioBox concept, however, may be the reliance on USB. While USB is a low-cost way to leverage the horsepower on modern PCs, it comes with limitations as a convergence interface. In this music application, the USB cable length limit of 5 meters effectively means the PC must be in the living room in order to connect with an end-user's stereo system. This limitation exists regardless of whether the USB Audio DAC exists in a stand-alone appliance or is built into another audio product.

For now, it appears that other interfaces might provide a better way to link the PC and living room worlds. For example, Diamond's new Digital Audio Receiver and 3Com's Kerbango connect to the PC via a LAN link, which would allow the PC to be located in another room.

Another product, Sonicbox's iM Remote Tuner, uses wireless technology to connect the PC to living-room gear. Sonixbox allows end-users to control PC Internet radio, as well as MP3 or Windows Media playlists, as if they were using a radio tuner. The unit works in conjunction with iM Tuner software (downloadable for free from the company's site), and comes with a base-unit that connects to the PC via USB, a receiver that connects to the stereo, and a remote control. Audio is transmitted wirelessly at 900 MHz. The system is optimized for a broadband connection, but a 56-kbit/sec modem will do.

However, consumers will have to make sure that their PCs are first equipped with a current version of Windows, a soundcard with DirectSound, Internet Explorer, and current versions of either Windows Media Player or RealPlayer. After you purchase, download, and/or configure all of the latter, the Tuner is currently available for just under $100. Playback quality is "quite good," the company says. One thing to keep in mind is that the same obstructions (thick walls, concrete) that can interrupt the signal on a cordless phone will also affect the transmission of audio content. But if playback is decent, the iM Tuner is a tidy alternative to what could otherwise be a cluttered living room.

—Leah Jiorle