by RON SCHNEIDERMANN
FM stereo radio broadcasting is about to get its first major upgrade since the service was authorized in 1961--a system with significantly reduced noise and more than double the currently available reception area. Final specifications for the FMX Extended Range Stereo System, described by its developers as "every bit as weighty" as the Broadcast TV Sound Committee project that established stereo sound for television, are now completed. Broadcasters and receiver manufacturers would have to hustle to pull it off, but we could be hearing the first over-the-air FMX-based FM stereo by early 1988. At least one automobile maker has all but committed to rolling FMX-equipped 1989 models off the line in the fall of '88.
The system was first described in Audio last year ("FMX: Long Distance Stereo, Clean as Mono," May 1986), at a time when many of its technical details were still in limbo. A final spec seemed to be all that was needed to get broadcast equipment manufacturers and receiver makers to adopt the new system.
A joint invention of Emil Torick, formerly vice president of the CBS Technology Center, and Thomas Keller, senior vice president for science and technology of the National Association of Broadcasters, FMX overcomes the noise penalty inherent in stereo relative to monophonic reception; it reduces the noise and distortion due to multi path reception in moving vehicles, and it permits improved stereo separation in outlying reception areas. Recently, Torick says, 14-dB improvements in signal-to-noise ratio were measured, yielding the equivalent to mono S/Ns over most reception conditions.
Development of FMX was threatened when CBS closed down its Technology Center in Stamford, Conn. in September 1986. Field tests at nearby FM public radio station WPKT in Meriden, Conn. had already been completed, but a demonstration during the 1986 Summer Consumer Electronics Show at WFMT in Chicago was "extremely disappointing," according to Gordon Carter, the station's assistant chief engineer, who recalls that there were enough problems with the system that he questioned the design concept. Torick doesn't disagree with that assessment, but now calls it "old, old history," noting that the WFMT demo was conducted with "inadequate technology, in the throes of the closing of CBS Labs." Torick and his technical staff continued to tweak the system under CBS auspices while a suitable buyer was being sought.
The new FMX development group, Broadcast Technology Partners, which acquired all rights to the FMX technology, will license receiver and broadcast equipment manufacturers for a nominal fee and then reap royalties on hardware sold. The partnership includes CBS, the NAB, the inventors, and an investor group, FMX Associates, headquartered in Bloomfield Hills, Mich. FMX Associates, which has controlling interest, and FMX Inc., the managing partner, are led by broadcast consulting engineer John F. X. Brown. To help develop and promote FMX, the NAB in May created a for prof it subsidiary called NAB Technologies Inc.
Meanwhile, two semiconductor manufacturers-Sanyo Semiconductor Corp. and Sprague Electric Co.-have announced plans to make available later this year the integrated circuits required to equip FM receivers with the new FMX technology. Sanyo might beat Sprague to market with its FMX chip samples, but Sprague is equally high on the system. "We anticipate quick acceptance of FMX by FM broadcasters and the receiver manufacturing industry," says Robert F. Milewski, manager of Sprague's linear products operation.
So do others. Approximately 45 equipment producers have already signed non-disclosure agreements with BTP, and at least one automobile manufacturer has said (privately, to BTP) that it intends to begin selling FMX-based stereo receivers as standard equipment in its top-of-the-line 1989 models, which are scheduled for introduction in the fall of 1988. Torick got another indication of manufacturer interest while on a trip to Japan in late June to attend the Audio Engineering Society's regional convention: Sanyo Semiconductor arranged a half-day seminar for him to describe and promote FMX, and 26 receiver manufacturers attended.
The strong interest isn't surprising.
About 30 million FM stereo receivers are sold annually in the U.S., and all are considered candidates for FMX. Car stereo receivers account for about half that market. Given their obvious problems with FM stereo reception, the car stereo receiver manufacturers, in particular, are looking forward to adding FMX to their products.
Actually, the receiver people liked FMX the first time they heard it demonstrated, early last year. "We're all waiting," says Paul Foschino, national product manager for Technics. In fact, several car stereo makers are considering adding an FMX-enable switch and indicator light to their FMX stereo models, even though it isn't necessary (an FMX receiver will automatically switch to the noise-reduction mode when tuned to an FMX station). One manufacturer calls it a "salesman's switch." But the receiver makers insist that broadcast equipment manufacturers and broadcasters make the first move, and there is every indication that they will. Four manufacturers of broadcast generators-Aphex, Circuit Research Laboratories, Inovonics, and Orban Associates-have developed and tested prototype FMX equipment. "We're ready to go into production. We're just waiting for the final specifications from BTP," says Chuck Adams, systems engineer for CRL, which demonstrated a stereo generator with a blank space labelled "FMX Encoder" at the NAB's annual meeting earlier this year. Torick believes that a few, if not all, equipment producers will demonstrate FMX encoders at two trade shows, Radio '87 and the Society of Broadcast Engineers Conference, both scheduled for the fall. FMX's chances of success were enhanced further by a survey conducted early in 1987 by the NAB, revealing that nearly 45% of FM stations are prepared to adopt FMX to improve the clarity of their stereo signals in outlying areas.
Transmitter modification is fairly straightforward and can be accomplished by broadcasters for only a few thousand dollars. FMX requires no more base-band spectrum so there is no impact on FMX subcarriers, and no modifications are needed to the broadcast studio or audio processing equipment. Additionally, it requires almost no additional modulation of the main carrier.
Receiver makers like FMX because it gives obvious added value to the product for only a few additional dollars in manufacturing cost. Most of that will be in the new FMX ICs from Sprague and Sanyo, estimated to cost approximately $2 initially, but likely to quickly drop to about 50 cents each as production and sales ramp up. To date, only NAD Electronics has introduced an FMX home receiver, which they first demonstrated at the Winter Consumer Electronics Show last year, and they build it with discrete components. More than 1,000 of these FMX Model 4300s have been sold, including several to BTP for testing purposes.
Other receiver makers have heard NAD's FMX system and are admittedly impressed. "We are really enthusiastic from the standpoint of car stereo," says Technics' Foschino. "But we don't want to build any carts before they come up with the horses." Pressing the point, he says Technics "wouldn't have units available in January on the broadcasters' word that they'll be on the air with FMX by that time. We wouldn't push our manufacturing until a lot of radio stations were broadcasting in FMX." Others agree. "When there are enough (radio) stations with a vested interest, we would hope to have an FMX model, or incorporate it into the line," says Chuck Wendt, marketing manager of Blaupunkt. "I have very high expectations for it," adds Gary Weissberg, director of product development at Sanyo Electric. "I saw a demonstration at the Consumer Electronics Show and was very impressed, not only by the extended coverage, but by the performance. It's a much quieter signal. It's going to be very quickly perceived as a new and desirable feature by the consumer. Everyone is just kind of waiting for the broadcasters to make the first move."
(Source: Audio magazine, Oct 1987)
DEPT. OF AMPLIFICATION (Oct. 1987)
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