Currents by John Eargle (Apr. 1992)

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RECEDING RECESSION


With the country in deep recession, it is paradoxical that the mood and tempo of the Winter Consumer Electronics Show were as upbeat as they were. Attendance was excellent, and the newly refurbished Las Vegas Convention Center was a welcome sight for all. I heard few people complain of business blues, and a number of new products were poised, albeit a bit cautiously, to make their big moves in 1992.

The chief new product is the Digital Compact Cassette, or DCC, which is targeted for both hardware and software introduction later this year. The release is contingent upon final Congressional action on a bill to set up a system of royalty payments to music copyright-holders based on unit sales of digital tape and recorders.

Because the encoding method used in DCC has been kept under wraps until recently, there has been considerable speculation on all aspects of data reduction as applied to music. Details of the Philips Precision Adaptive Sub band Coding (PASC) have recently been made known, and a number of DCC recorders are now in the field, allowing listening tests to be made.

(Editor's Note: See David L. Clark's feature article on the subject in this issue.) I had the pleasure of participating in non-rigorous listening tests in BASF's demonstration room at CES. BASF is a major supplier of blank tape for prerecorded cassettes, and their interest in DCC is a natural consequence of the fact that DCC can be phased into tape duplicators' normal production channels at a very competitive speed ratio of 64 to 1. In BASF's setup, a CD had been directly (digitally) copied onto a DCC tape. For the test, the CD and DCC tape were roughly synchronized, with careful attention given to level matching, and could be directly compared through switching. At all times you knew which was playing; the intent was simply to determine if there were any significant differences between the two.

Auditioning was made through the very high-resolution Sennheiser Orpheus headphone system, and I must state that I could not hear any differences between CD and DCC on a variety of music, including organ, orchestra, and piano. This certainly does not mean that there are no differences, only that they were not audible in normal listening. The various Dolby analog noise-reduction systems can all be "fooled" by certain signals, but for the most part the process is benign and beneficial. The same may logically apply to DCC. Many record labels have joined the DCC movement and stand ready to issue their catalogs in the new medium. The hardware alliance extends virtually across the board, and only Sony seems to be missing from the list. Sony has its own rival system, the Mini Disc, a recordable CD-type disc that itself makes use of data reduction. At least one company, Denon, intends to support both DCC and the Mini Disc. Presently, it looks as though the momentum of DCC, and its general endorsement by the recording industry, places it in a clear position of leadership.

Video truly dominates the scene at CES. Most of the pertinent displays were on the main floor of the Conven tion Center, with specialty displays in the Mirage Hotel. High-definition TV (HDTV) appears no closer to becoming a commercial reality than it did two or three years ago, and the costs involved clearly suggest that it might never be more than a specialized medium for industrial and technical displays. The greatest benefit of HDTV is its seamless picture, free of the raster lines which afflict normal TV. Today, the average home TV viewer watches the set at an included angle of perhaps no more than 10° to 15°. At that angle, the 525 horizontal lines on the screen may not be noticeable as such, but at wider viewing angles these raster lines become a nuisance. The technique of line doubling has helped to bridge the gap between normal TV and HDTV. A major innovator in this field is Yves C. Faroudja, whose Super NTSC system has offered a workable interim system between conventional TV and some ultimate form of HDTV. In its simplest form, line doubling merely interpolates an extra line between adjacent transmitted horizontal TV lines, effectively producing a field of more than 1,000 lines. When the TV scene is fairly stationary, this works very well. But when the scene is full of motion, other techniques must be invoked to handle the "jerkiness" which simple interpolation produces. Faroudja is clearly the leader in this field, but their line doubler, at nearly $15,000, is beyond the reach of most consumers. Line doubling is a video relative of audio data reduction used in DCC and MD, and I suspect that we will see intensive product development in this area during the next 18 months. It would not surprise me to see an effective line doubler for $2,500 in the next year or so.

Another relatively new area at CES is environmental audio/video. This includes piping sound around the house, often integrating it with inter corns and security systems, and generally includes hiding loudspeakers in walls. While it may be a boon to wives and interior designers, it has traditionally been considered low-fi. But things are changing for the better. Wall loudspeakers, subtly hidden by their grilles, now provide wideband response, and subwoofers can now be located in walls as well. Major suppliers of electrical contracting gear are now routinely supplying switching and routing equipment for multi-room systems. In advanced applications, computer systems can be used for overall control.

As we have seen in the last five years, car stereo is where most con sumers spend the bulk of their audio only budget. The dominant factors in car stereo are, increasingly, the integrity of center-channel imaging, extended bandwidth, and low distortion. And no stereo system is considered first-rate today unless it has a CD player (or changer in the rear trunk). The major manufacturers displayed "competition cars," which demonstrate the full range of what they offer, both in loudspeakers and signal processing.

Two years ago, digital signal processing (DSP) represented an opportunity for car stereo to expand from its traditional confined listening environment to something larger, via reverberation synthesis. As normally implemented, DSP provides a wide variety of reverberation or ambience programs that operate on the stereo program.

The ambience information is spread about the car's normal four loudspeaker channels, while the primary stereo information stays in front. The intent is to provide a more natural listening environment, which can be done if a subtle hand is on the controls. Unfortunately, this is rarely the case, and as things have developed DSP has so far not lived up to its initial promise. The manufacturers are responsible as well, since they have made it all too easy to dial in overdone effects.

As for high-end audio at CES, most manufacturers were again ensconced in the tacky old Sahara bi-level complex. The hotel has few really good demonstration rooms, and air handling and ambient noise are real problems.

There was also little new to observe, but this is not surprising considering the relative maturity of loudspeaker and amplifier technology, which are the mainstays of the high end. Something needs to be done to provide a more effective forum for this small but important segment of consumer electronics. It is also the most "American" segment of the show, which should count for something.

(adapted from Audio magazine, Dec. 1991)

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