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Digital Recorders: Technical Marvel, or Audiophile’s Disaster? With AM-Japan-Digital

July 26, 1992

Digital Recorders: Technical Marvel, or Audiophile’s Disaster? With AM-Japan-Digital Compression Box

TOKYO (AP) _ For decades, the goal of hi-fi equipment designers has been to recreate live music as perfectly as possible by reproducing every sound with a minimum of distortion.

Now, a new generation of stereo equipment due out later this year is throwing that approach out the window - along with at least three-quarters of the music data.

The new products, Philips’ digital compact cassette and Sony’s mini disc, represent a turning point in sound recording techniques that’s causing some audio purists to nervously twist their speaker cords.

″I’m worried about how they will sound,″ says Noboru Azuma, a manager at Dynamic Audio, a Tokyo hi-fi store. ″It’s quite likely that they won’t sound as good as compact discs.″

With slipping sales of conventional analog audio cassette tapes, the most popular home recording medium, companies are trying to boost the market by offering new products that record digitally - the crystal-clear method popularized by compact discs.

The digital compact cassette machine uses tapes about the same size as today’s analog cassettes, and can even play these tapes. Mini discs are about half the size of CDs and are enclosed in protective plastic cases, like computer diskettes.

What worries audiophiles is a technology called digital compression that squeezes sound onto the slow-moving digital compact cassette or the tiny discs.

Based on studies of how humans hear, digital compression is used to eliminate sounds that designers say are inaudible under most conditions - either because they’re too soft or are masked by louder sounds.

The digital compact cassettes eliminate three-quarters of the original sound information, while mini discs discard an even more astonishing four- fifths of the sound data so they can hold the same amount of music as a full-size CD.

″Only that information which is important for human hearing is recorded,″ says Wim A. Wielens, managing director of Philips Consumer Electronics’ audio business group.

That’s a significant shift from the traditional hi-fi goal of reproducing every sound.

″In the past, engineers tried to get as close to reproducing live music as possible,″ says Shizuki Matsubara, manager for digital compact cassette promotion at Matsushita Electric Industrial Co., Japan’s leading consumer electronics company, which is co-developing DCC with Philips, a Dutch company.

″But we’ve come to realize that live music inevitably sounds different from recorded music. Human ears are smart, and can always tell the difference,″ Matsubara says.

As a result, designers of the new cassette have focused on creating a system that sounds good as a recorded music source, and for most people is indistinguishable from a CD, he says.

″There are some conditions under which it’s possible for some people to tell the difference,″ Matsubara says. ″But in most cases it’s very hard to do so.″

In many listening situations - a car, a noisy house or while jogging - it’s unlikely that most people could hear any difference. The new products share the clarity and lack of background noise that make CDs so appealing.

What they lack, according to some listeners at comparison tests, is much less apparent - shades of musical detail and complexity that can only be heard under close-to-ideal conditions.

″For the portable applications that we’re targeting, like cars and jogging, it’s really not going to be that critical,″ says Sony Corp.’s David Kawakami.

Matsushita compares the process to photographs in which the main subject is sharply focused but the unimportant background is slightly blurred.

Digital compression was not the only option available for digital home recording. Digital audio tape, a separate digital tape-recording system that doesn’t use compression, already exists. Newly developed lasers also may make it feasible to put a CD’s worth of uncompressed sound on the smaller mini disc.

However, record companies that resisted DAT because of its ability to make perfect copies of CDs are likely to feel more comfortable with the new products because of the changes that result from digital compression.

For home hi-fi use, Sony says CDs will continue to be the reference standard.

The new products will be available as blanks for home recording or with pre-recorded music. The price of a mini disc will be about the same as that of a top-quality blank analog cassette.

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