We all deal with wireless issues. I’ve had my share over the years, and I have written about some of them in this column. We have an annual PGA golf tournament right down the road that steps all over our frequencies, but otherwise, we have relatively pain-free RF the rest of the year. I attribute that mainly to planning and the fact that we are in a fixed indoor environment. I pity the touring crews that carry 50 channels or more all over the world.
Have a Plan — and Stick to It!
One of the most important aspects of a successful wireless deployment is having a plan and sticking to it. We have 46 channels of wireless across our campus, which includes two worship venues and all of the ancillary spaces such as the youth and choir practice rooms. Each of these spaces must be coordinated to form a fully functional wireless plan.
We started by purchasing different frequency bands for different parts of the campus. For example, our main sanctuary is in the Sennheiser A1 Band (470 – 516 MHz). Our contemporary worship space is in Sennheiser’s A Band (516 – 558 MHz) and our ancillary spaces are spread across those two bands, depending on where they are located on campus.
Each channel’s frequency is coordinated and documented, and I’ve assigned priorities to each channel. Pastor wireless channels and IEM systems have an “A” priority, and these channels get the cleanest frequencies with the best intermodulation rating. Vocal microphones get a “B” priority, and drama mics and spares get a “C” priority.
I’ve also got pre-coordinated spare frequencies available and documented so I can switch to them at a moment’s notice. All of this pre-planning keeps my head wrapped around our wireless systems and minimize issues from week to week.
Remote Monitoring
Remote monitoring software is available to virtually anyone these days, and you should take advantage of it. It can help you solve a host of common day-to-day wireless issues. Software packages such as Shure Wireless Workbench, Sennheiser Wireless Systems Manager or Lectrosonics Wireless Designer are free, cross platform and relatively easy to use. The only prerequisite for using them is that your transmitters and receivers need to be networked together and the network needs to be accessible from your remote monitoring computer. An inexpensive Ethernet switch and some Cat-5e cable should be all you need to get this up and running.
Opening and reviewing our remote monitoring software is one of my first chores every Sunday morning. Most weekends, everything looks normal and I go on with my business. We are located just outside of Orlando, FL, so we have a relatively quiet RF environment, and being indoors, our RF noise floor is low, but nonetheless visible on the RF meters in our software. Recently, I encountered two situations where remotely monitoring our wireless saved us from a much larger problem. Both issues were self-inflicted, stupid mistakes that could have become much bigger issues had I not caught them early with our wireless software.
A few months ago, I was doing my usual checks around 5:30 a.m. on Sunday morning. I turned on all the gear and fired up Wireless Systems Manager. I noticed that I wasn’t seeing any RF noise floor on a single channel. That was unusual, so something must be wrong. All of the individual receivers showed up properly, so it wasn’t a networking issue. A quick look backstage revealed that one of our five antenna distribution units hadn’t turned on properly. This happens to be the main distribution — the one that feeds all of the other units. A quick reboot, and everything looked normal again.
Then, a few weeks ago we mistakenly forgot to change out the rechargeable batteries in our wireless handhelds. This one is rare, as we have a pretty good battery management system in place, but this time it slipped through the cracks. Fortunately, our monitoring software at FOH indicated the batteries were low, and I was able to get all of the batteries swapped out before anyone was the wiser.
Gain Structuring
Gain structure is an oft-overlooked yet critically important part of successfully operating a wireless system. A unique problem I’ve run up against occurs when an artist’s personal monitoring system is feeding an IEM transmitter. Wireless gain structure managed by a skilled audio engineer should be a simple matter. But when an IEM transmitter’s gain structure is handled by a musician, the scenario goes like this: The praise band has personal monitoring system controllers on stage (Aviom, Roland M48, Pivitec, Klang, etc.). The outputs of their personal mixers feed a wireless IEM transmitter and their mix is then received by their wireless bodypack receiver.
Here, the problem is two-fold. First, musicians don’t always know how to properly gain structure a wireless system. Second, even if they did, they don’t have the ability to meter or monitor their gain structure. As the audio engineer, you may be able to see that they are clipping their transmitter from your monitoring software, but by then it could be too late. The trick here is to have them set the level of their bodypack receiver high enough that they won’t ever want to clip the transmitter (because it would be too loud!).
On our system, we’ve found that if the band starts with their bodypack level at roughly 75 percent and uses their personal monitoring controller to make any level adjustments, the gain structure will stay reasonably in check. This requires a weekly reminder to “start with your wireless pack at 75 percent,” and even then, I’ll still find them clipping their transmitter from time to time.
One thing that I’ve been meaning to try but haven’t gotten around to would be to loop the output of the personal monitor mixers back into our audio console, apply some limiting there that I could manage during rehearsals and services, and then send that back out to their wireless transmitters. I’ll get around to that one of these days.
There are many little details that go into proper wireless operation, and these are just a few I’ve encountered recently. Proper planning and coordination is the key to keeping wireless headaches to a minimum and making sure that your praise band and pastoral staff are confident in your wireless system.
Vince Lepore is the technical director at St. Luke’s United Methodist Church in Orlando and teaches live production at Full Sail University
