Tech Focus: Bodypack Transmitters, Part 1 — A Growing Role in Sports Sound
The devices are becoming smaller, tougher, and increasingly flexible
The wireless bodypack may be hitting some physical limits when it comes to size and power, but its capability for putting on-field audio on the air for sports broadcasts has never been more in demand.
Broadcasters have been collecting sounds from the fields and the courts for decades, mostly from the sidelines. For several years, the NFL had placed a lavalier microphone on the umpire’s cap, to pick up the offense’s cadence. When the league moved that official’s position from the middle of the defensive line to well behind the offense for safety reasons after 2010, it left more than a hole on the gridiron: fans at home had grown accustomed to hearing the scrimmage sound up close.
It took another four years of experimentation and bargaining, but the NFL now places lavs on either the center or the guards, adding a new dimension to the game’s sound. Meanwhile, companies like Quantum5X were developing player-worn transmitters well adapted to the physicality of sports, such as the lightweight bodypacks sewn into jerseys for NBA games. The robustness of their design has let them be placed even closer to the playing field, such as the transmitters buried in the ground in the outfield and around home plate and the pitcher’s mound during postseason MLB games in recent years. The bodypack has become the sixth man of broadcast-sports audio, able to go anywhere, anytime.
Size Still Matters
The trends around size and weight, generally dictated by battery dimensions, remain in place, according to Lectrosonics VP, Sales, Karl Winkler. He notes “increased emphasis on small and tough units; and lots of flexibility in the units, like variable power settings, wide tuning range, and infrared sync.” What’s new for this round of the company’s products is built-in recording functionality, “so that, in situations where a wireless might not be practical, the unit can be put into recording mode and high-quality audio can still be captured for use in postproduction,” he explains. “Rather than requiring [field engineers] to keep several units in the kit to accomplish these tasks, the SMWB/SMDWB [models] have all these features and functions built in.”
Paul Johnson, CEO of PlayerMic developer Quantum5X, sees growing demand for more remote control of bodypacks, including power management and frequency changes. The former is becoming more important as bodypacks move off the body and into other applications, such as being implanted into the ground on playing fields; Q5X’s AquaMic was used in that manner during several postseason MLB games, planted in the infield around bases, the pitcher’s mound, and home plate.
Remote control of frequency changes is becoming more critical in the wake of the recent spectrum repack, says Johnson, adding that, as these types of bodypack transmitters become part of a broadcast’s live sound, as they were during Mylan WTT matches this year, the ability for the A1 to quickly shift frequencies as the spectrum environment around them changes dynamically will grow in importance.
Q5X has also focused R&D attention on optimizing the performance of its remote-control units, which operate at 2.4 GHz, managing transmitters in the UHF range. “The 2.4 GHz noise floor is higher than ever as more mobile [devices] enter that spectrum,” Johnson explains. “The sound crew will do their setup in an empty venue, and there’s plenty of space, but, when it fills up with 30,000 fans with mobile phones, that changes everything. We have dramatically improved our 2.4 GHz performance to ensure reliable remote-control functionality in these noisy environments”
The future of bodypack design will likely hinge on developments in battery technology. Driven by the emergence of electric vehicles and other products, battery size could be greatly reduced in coming years. One such technology is Prieto Battery’s copper-foam–substrate battery. The copper foam is approximately 98% air, or void space; the anode and separator material are applied via electrodeposition. Then, the cathode material is applied as a liquid slurry. It’s a bit more complex than an Energizer 9-volt, but it could someday become as common. That could take bodypack technology into the nano realm.
CLICK HERE for Tech Focus: Bodypack Transmitters, Part 2 — A Look at the Leaders.