Bodypack Transmitters: The Digital Category Expands

Imagine expecting a piece of technology to get smaller, add more complex features, and be able to withstand the equivalent of a train wreck 25 times an hour. These are the kinds of performance parameters routinely demanded of electronic systems for NASA and the Pentagon. Oh, yeah, and the NFL.

As viewers have shown an appetite for more-intimate audio from sports broadcasts, the bodypack transmitter has become a must-have piece of equipment on the field, the court, and, particularly, the gridiron, where, for two years, the NFL has been experimenting with on-field microphone placement as it seeks to bolster its on-field audio. Key to that initiative is the bodypack transmitter, which has to be small, robust, and reliable in sports’ most demanding environment.

A Digital Future
The transmitter also has to be discreet, as in circumspect, a trick that until recently has been hard to perform. Only a single manufacturer, Zaxcom, has had a fully digital and encryptable wireless system, its TRX900, on the market for any significant length of time.

In the past year, however, two more such systems have come to market: Shure introduced its ULX-D digital, encryptable wireless system capable of 24-bit audio and single-, dual-, and quad-channel receivers in January, and competitor Sennheiser debuted its SK 9000, a lightweight, encryptable transmitter that uses infrared synchronization and exchangeable lithium-ion battery packs, at the AES Show in October.

Zaxcom, a relatively small manufacturer in an industry sector dominated by large international companies, had its digital solution in place at a propitious moment, as the NFL sought a way to replace sound from the mic previously worn by the umpire, who in 2011 was moved out of harm’s way, farther back from the line of scrimmage. The NFL has been deploying Zaxcom’s TRX900 LAS version, which uses two lavaliere microphones to create a stereo signal with a single transmitter. The mono version is also used by NBA coaches.

However, the arrival of larger systems from Shure and Sennheiser, offering high-resolution audio and larger frame sizes to accommodate more channels, will put this nascent category into play.

Neither Shure’s nor Sennheiser’s new digital systems have been used by any major-league teams yet. Sennheiser’s became available after the start of the NFL and NBA seasons this year, and hockey is a non-starter this year. According to Shure Category Director for Wireless Products Erik Vaveris, that company’s system only recently was expanded to a full rack in September, a configuration that will make it more desirable at the major-league level.

“We’ve made a lot of progress in regards issues like power management: the ULX-D has outstanding battery life and can run on alkaline AA batteries or rechargeable,” he says. “Digital wireless has tremendous potential, and it will be exciting to see how it evolves.”

Joe Ciaudelli, director of advanced projects engineering at Sennheiser, says the SK 9000, which took the better part of a decade to develop and offers very low latency and both compressed or uncompressed audio, has been demonstrated to ESPN and other broadcasters since it was introduced. He expects it to be evaluated by the NFL and other leagues in the near future. “We think this is now the benchmark for bodypack transmitters.”

However, new and larger digital systems come with higher price tags. According to Colleen Goodsir, who directs Zaxcom’s marketing, the TRZ900’s basic system costs about $2,000, a fraction of the cost of one of the larger-frame systems. What the company doesn’t have, she acknowledges, is the marketing clout of its larger competitors, and it will have to work to leverage its early successes in the rapidly expanding category. Sennheiser’s Ciaudelli tips his hat to Zaxcom, calling the manufacturer “nimble,” but adds, “This is going to be a more competitive [category] now.”

Analog Dog, New Tricks
This won’t put the kibosh on analog systems, however. Several key performance features make analog bodypacks valuable for sports in general and football in particular: they can be very small, thanks to being able to be sufficiently powered by a single AA battery; analog’s more efficient power management also lets them handle heat dissipation better; and analog has inherently low transmission latency. For instance, Quantum5X Systems’ Player Mic has been used extensively by various baseball, basketball, and football teams, including the NFL’s St. Louis Rams for the team’s self-produced television programming.

Quantum5X CEO Paul Johnson notes that the design has evolved over several years based on feedback from players and teams, producing a very small and flexible — the outer casing is made from rubber — transmitter that is designed to not injure players when they fall on them but still performs in a rough environment and offers battery life that lasts into overtime.

And the analog transmitter has been learning some new tricks. A relatively recent development has been more remote parameter control, such as the ability to vary signal strength remotely, allowing those who manage the wireless RF to lower signal intensity to conserve battery power in the course of a game that’s beginning to run long.

Also, says Karl Winkler, director of business development at Lectrosonics, whose dual-battery SMQV analog bodypack transmitters are being used by the NFL, “Analog offers better spectrum efficiency, because it’s better able to concentrate the energy into a narrower range of spectrum than digital can.” He adds further that analog also enables higher channel counts and longer range than most digital systems can, while also being able to withstand the pummeling of an NFL scrimmage. “Digital systems can be very good — wideband digital offers a good-quality signal — but they can’t compete with analog when it comes to channel count.”

Bodypack technology has reached a turning point now that more encryptable digital systems have come to market. Pro sports leagues, teams, and broadcasters tend to be cautious when it comes to implementing new technologies, and there’s no reason to think that they’ll behave any differently when it comes to embracing fully digital bodypack transmitters. But it’s also fair to say that, as far as these new products go, it’s now game on.