Stability in the face of interference is not the only characteristic of a solid wireless system. The quality of the microphone, preamp and converters are all vitally important for delivering clean, reliable audio wirelessly. Image courtesy of Sennheiser and Flatirons Church, Lafayette, CO.
When church techs get together, their stories often have an almost folkloric resolve. They inevitably turn to tales of services gone wrong, equipment failures, and other AV-related disasters ranging from hilarious to truly frightening. Yes, we smile and nod our heads in agreement but know all too well that it’s only a matter of time before we too will endure a similar nightmare of epic proportions. The common thread often comes down to one culprit: wireless systems.
From the occasional dropout to continual RF interference, even the smallest disruptions in audio quality are not only frustrating for the audio engineer but distracting, even maddening for the listening audience, speakers and performers. While unforeseen circumstances crop up despite our best efforts, those should be seen as a rarity, not commonplace. The excuse of “Well, it was working earlier,” simply does not hold merit any longer.
Learn more about how Lafayette, Colorado-based Flatirons Church gets consistent, high quality sound across all of their campuses from Audio Director, Bryce Boynton.
As the popularity of wireless equipment has grown exponentially throughout the years, so too has the landscape of frequency coordination within a shrinking frequency spectrum. Not only have manufacturers been forced to innovate solutions to alleviate the strain on bandwidth and performance, but end users must now have 1) a greater knowledge when purchasing new systems, 2) have greater expertise in operating multiple wireless systems, and 3) exercise much greater care in deploying additional wireless systems that inevitably get added as part of Christmas services.
Fortunately, new innovations across all parts of wireless systems–from transmitter, to receiver, to antenna, system monitoring, and internal components–have helped ease the pain and help end users build a rock solid wireless system. And when we understand the foundations of reliable wireless deployment, our shared stories will be those of triumph rather than frustration.
Playing the Game vs. Fighting the System
Houses of worship constitute one of, if not the largest group of customers for wireless equipment. What was once reserved for the speaking pastor or worship leader has now been expanded to vocalists, instrumentalists, and full worship teams running in-ear monitor systems. This trend is the result of higher quality systems being introduced to the marketplace, ease of operation and affordability too. However, recent developments in the available wireless spectrum have caused churches to take a second look at their existing wireless systems and pay more attention when they add new wireless systems.
In recent years, the FCC took a bold step regarding the 600 MHz frequency spectrum–a frequency split that was widely used among existing wireless microphone systems found in churches. This spectrum was recently auctioned off and reallocated to telecom giants for cellular use and digital TV broadcast. And as cellular use skyrockets among both users and available devices (IoT – the Internet of things), existing wireless users in the 600 MHz spectrum are left with a serious dilemma: move to a different band, risk major problems with interference or potentially find themselves breaking the law.
David Missall, manager of customer development and application engineer for Sennheiser, says this reallocation of bandwidth, both with the 600 MHz spectrum and beyond, changed the game for system deployment. “With traditional analog wireless systems, you generally need more bandwidth to operate the same number of channels in a given spectrum than digital wireless systems,” he says. This likely means that, unless your church currently operates digital wireless systems, your existing systems require a wide swath of spectrum to deliver clean audio. As available spectrum shrinks, the system that operated flawlessly last year may not deliver the same performance this year. Missall adds, “So in turn, the margin for error in how many [analog] systems can be safely stacked in a given bandwidth is much smaller than for high quality digital wireless systems like the Digital 6000.”
As we’ve established, since the available UHF spectrum has shrunk and become significantly more crowded, many church wireless systems are operating on shaky ground. For many, this means taking a chance, with church sound techs simply guessing that the wireless systems are working properly. Yet when it comes to wireless stability, speculating about something you cannot see–in this case wireless congestion and RF environment–is a recipe for disaster. So rather than fighting the system, we need to learn how to play the game, because this problem is not going away anytime soon.
Components of Solid Frequency Coordination
One of the critical aspects of any wireless system involves the number of compatible systems being used simultaneously. For a smaller church with minimal needs, a wireless system might involve only one or two wireless channels. In a situation like that, the options are plentiful. If problems occur, one option may be to move to a digital system that operates within the 900 MHz and 2.4 GHz spectrums. However, because these are unlicensed bands, the potential for interference from other digital devices such as WiFi routers and Bluetooth devices can affect performance. However, digital wireless systems are extremely viable for the right application.
For a larger church using a much higher number of wireless systems, the UHF band from 470-608 MHz still remains one of the best options due to tighter control from the FCC. However, it’s important to note that many of the television channels that used to reside in the 600 MHz band will be migrated to the lower UHF frequencies, leaving less open spectrum in many populated areas.
However, digital wireless systems, which operate in the UHF band, offer enhanced sound quality and a significant increase in the number of channels that can be packed in side by side.
So how does a church audio engineer safely deploy new wireless systems, or diagnose problems with wireless systems that may have recently been operating reliably? Bryce Boynton, audio director at Flatirons Church in Lafayette, Colo., located near Denver says, “We use a software-based Wireless Systems Manager from Sennheiser to manage all of our channels and systems. It’s been crucial in making sure we know exactly what’s going on with the RF environment rather than taking a guess.” Boynton recently deployed a new Sennheiser Digital 6000 two-channel wireless system for the church’s teaching pastors. “Since we broadcast to other campuses and stream online, it’s critical that our wireless system for the pastor is rock solid every service,” Boynton adds.
Sennheiser’s Missall advises churches who are making purchasing decisions by saying, “While there are entry-level wireless units all the way up to cutting edge professional systems, I always recommend churches buy the best they can afford. Especially in a large-format environment where a large number of wireless channels are going to be used. And have an RF analysis done of your space, so that you can have an idea of the RF environment, and what you’re up against.”
Understanding your church’s unique environment, prioritizing your wireless systems, purchasing the best you can afford, and making informed decisions rather than guessing on frequency choices will pay off for you in the long run. All churches, from small gatherings to the largest venues, can employ these foundations and be assured of solid wireless performance and peace of mind.
