While it may not be the societal monkey wrench that is expected from the Y2K situation, those whose livelihood depends on reliable wireless microphones are beginning to experience a more hostile working environment. The introduction of digital television, combined with the proliferation of low-cost UHF and VHF wireless systems and the reallocation of some UHF frequencies for two-way radio for fire and safety communications, are combining to make life more difficult for professional users of wireless microphone systems.
In bygone days, when the VHF band became overly cluttered, higher-end wireless microphone users simply migrated to the UHF spectrum, where acres of unoccupied bandwidth existed. Pro users then had a near-exclusive world in which to operate. In time, the effects of VHF clutter prompted some manufacturers to begin building lower-cost UHF systems for the masses, and wireless soon became a victim of its own success. Sales of single-channel VHF systems nearly became the exception rather than the bread and butter of music stores and sound contractors. "Frequency agile," or multi-channel UHF systems, became the rage and, according to some, the UHF band is now more cluttered than the VHF band was just a few years ago.
For the professional touring act, theatre production, or high-end corporate event, it has become like trying to run the Indy 500 in rush-hour traffic. Sound technicians on Broadway were appalled to find that "common" users were now threatening their Camelot. Le Miz was now in competition with the local karaoke parlor.
But it is not just the clutter caused by other wireless microphone users that is making life difficult. On November 1 of last year, the first digital television stations in the United States fired up their signals. Currently, about 40 stations nationwide are broadcasting digital signals, mostly in major markets like New York, Chicago, and Los Angeles. But the FCC has mandated that more than 1,600 stations convert to digital television in virtually every TV market nationwide. Although there are only 40 digital stations now on the air, the balance of the remaining 1,600 stations will use additional bandwidth within the existing VHF and UHF spectrums. Stations will broadcast both their existing analog signals plus the new digital signals--essentially doubling the amount of occupied bandwidth and severely curtailing available spectrum for wireless microphone operation. Although professional wireless users in the major markets are beginning to feel the effects of digital television, in each and every case, the c lutter is going to get worse. New York City, for example, currently has four television stations broadcasting digital signals. When it is fully built out, the area will have more than 20. Markets like Buffalo, Nashville, and Salt Lake City are the next to be affected. And, within three years, markets the size of Savannah, GA, Eugene, OR, and Bakersfield, CA, will be more difficult areas for wireless microphone users.
In addition to the invasion of DTV signals, radio stations are likely to begin broadcasting digital signals. And, the FCC has recently moved to reassign certain portions of the upper UHF band for two-way radio communications devoted to emergency, fire, and safety services.
In short, more signals than ever are being required to squeeze into less available bandwidth.
Yet, in reality, some professional wireless microphone users--those who thought the UHF TV band was their little fiefdom--are space invaders themselves. According to the FCC, the VHF and UHF TV bands are legally allocated and licensed to broadcasters. Use of wireless microphones for theatre, theme parks, touring productions, etc, are barely mentioned in the FCC's frequency allocation mandates, and they are not required to have a license. So there is little political clout or legal precedent from which to mount a fight.
So what is in store for the future? "Wireless users and dealers will have to become more savvy, and they will have to learn more about frequency coordination," says Bruce Jones, vice president of marketing at Lectrosonics, manufacturer of wireless microphones and audio processing equipment based in Rio Rancho, NM. "Over the next few years, it may require some innovation on the parts of users." Jones notes that the advantages of close miking using wireless systems have improved the audio quality in nearly every area including theatre, ENG (electronic news gathering), and live and prerecorded television. "Today, many audio problems can be solved by simply throwing some more channels of wireless at them. That may not be the case in the near future," Jones says.
"While the price of wireless units keeps going down, the environment keeps getting harsher," adds Gary Stanfill, president of Vega, a wireless systems manufacturer based in El Monte, CA. "The quality of equipment that it's going to be necessary to survive is going to have to be higher. So the customers are going to have to adjust their expectations."
Stanfill believes that, for the professional user, newer equipment will be only one part of the equation. He believes that a more sophisticated "systems approach" will be required, where multichannel wireless systems will need expert installation, maintenance, and, possibly, operation.
He draws parallels to the early days of audio system design. "It used to be that you would go buy some amps, a mixing console, and some speakers, hang them up, and they sort of worked," Stanfill contends. "But then things began getting more sophisticated. The public became more aware, and suddenly sound system design and acoustic design became technically challenging."
It also became big business. Another trend in the making? Maybe so. Stanfill says he is aware of several companies that are entirely dedicated to setup and maintenance of wireless microphone systems. And they are turning down work. "Users will have to 'hire, train, or contract out' this function in order to implement reliable multichannel systems. So the costs of the gear, the system design, and the maintenance is going to go up," concludes Stanfill.
Another possible alternative is already on the market. X-Wire, a Sacramento, CA-based company, has come out with a digital wireless microphone system that operates in the ISM (Industrial, Scientific, and Medical) band. Digital wireless systems produce a uniquely encoded data stream. Guy Coker, X-Wire's vice president of operations, says the encoding "locks out everything except your actual data stream." He maintains that digital wireless systems also produce superior dynamic range and frequency response. "We're passing 10Hz on the bottom end, and at least 20kHz on top. I don't know of any analog systems that can do that," he says.
So why aren't all manufacturers jumping on the digital bandwagon? "Theoretically, [digital] is the solution. But the solution is by no means cost-effective yet." says Uwe Sattler, technical director at Sennheiser, a manufacturer of microphones, headphones, and wireless systems based in Wedemark, Germany. (Sennheiser's US operations are based in Old Lyme, CT.) "There are a lot of problems to be worked out with digital technology and the available hardware." One problem with digital wireless systems is the limited number of channels that can be operated simultaneously in the available bandwidth. Sattler says the average theatre production currently uses between 24 and 40 wireless microphones. But 20-bit audio, the minimum acceptable for professional use, takes up exponentially more bandwidth than the closest comparable analog wireless signals. Therefore, he says, it is only possible to operate four to six digital systems channels simultaneously in the 915MHz ISM band. The fact that X-Wire's digital wireless m icrophones systems are multichannel systems with just five available channels seems to verify this assertion. "That is not sufficient for most of today's professional productions," Sattler says.
Sattler and other critics go on to say that the ISM band is a "dumping ground" and a "free-for-all" band hosting everything from garage door openers to wireless automatic door locks for automobiles.
The 915MHz ISM range is the bandwidth that other wireless manufacturers are exploring because of its unlicensed available spectrum. But this range is relatively crowded with all kinds of things, including the majority of home-style wireless telephones that are sold today.
Sattler notes, "The 2.4GHz ISM band is another possibility that is being looked at" for digital wireless systems. But he says that bandwidth is not the only catch to designing and manufacturing digital wireless microphone systems. While there are lots of digital wireless telephone systems available, "the quality of that audio is severely limited." Sattler continues, "You can design equipment relatively easily with telephone-bandwidth audio, and do it fairly inexpensively because the economies of scale apply to the available hardware. But you cannot simply scale this up from a six- or eight-bit to a 20-bit system for professional use. In attempting to do this, you may have to go to custom chips, if you want to do it right." The only way to recoup development cost is to go to large-scale integration, he says. And the numbers simply aren't there in wireless microphones. "Our industry has had their tongues hanging out for the hardware to become available," Sattler adds.
Yet, while most agree that digital wireless is the wave of the future, it seems ironic that the solution to the clutter problem caused by digital technology is likely to be digital technology. So, while manufacturers research and develop their own solutions, a ray of hope exists for those heavily invested, or heavily committed, to their current analog systems. Beginning in the year 2006, analog television broadcasts will be phased out, and stations must return their licenses for these frequencies to the FCC. While demand for these newly vacated channels may develop, there will, if even for a short time, be a reduction in the number of high-power VHF and UHF television signals, providing some relaxation on the stranglehold that is only now beginning to tighten.