Photo courtesy of Rock Harbor Church, Meridian, ID
Cutting the cable with wireless can make many sound reinforcement situations more comfortable for the presenters--and less visually obvious. This is especially true when combined with the latest generation of miniature headsets and lavalier microphones. Wireless mics grant increased freedom of movement to the pastor, the ability to easily carry a mic out into the pews, and the means to unobtrusively capture voices during the Christmas service and other presentations.
However, even though the technology has become much easier to manage, using wireless microphones--especially with multiple channels--is not foolproof.
CPM takes a look at everything from battery management to frequency coordination, to ensure that your upcoming events go more smoothly.
Battery life
We’ll begin simply. Transmitters run on batteries, typically a pair of AA alkalines or sometimes rechargeables. Make sure as you go into a service or event that all transmitters have battery life to spare, so that a dead transmitter doesn’t interrupt the sermon. Many of the newer and higher-quality wireless systems have fairly accurate indicators of remaining battery life. Note the remaining time and act accordingly. If you have back-to-back morning services, take the total time into account.
Now that the norm for most transmitters is eight or more hours of use with fresh batteries, you don’t necessarily need to change them before each use--although you will want to consider this for important events. And make sure to turn off the transmitters when you’re done.
Locking controls
Wireless microphone designers spend a good bit of time selecting and placing transmitter switches and other controls in locations where they will not be accidentally activated. These may be recessed so that they require a fingernail to move, or placed near an antenna port or connector so they’re less likely to be pressed. In addition, many systems allow the sound engineer to temporarily lock (disable) certain controls like the on/off switch, so that an unknowing move or an attempt to mute the transmitter won’t turn it off in mid-performance.
... make a point of checking that the transmitter settings are correct, and then lock those switches during the service or event. Perform any necessary muting at the mixing console.
In most cases, the microphone users don’t need to adjust their transmitters, leaving the sound engineer in charge of making those decisions. So make a point of checking that the transmitter settings are correct, and then lock those switches during the service or event. Perform any necessary muting at the mixing console. Also, some systems have a two-way communications path between the receiver (or wireless control software) and the transmitter, so adjustments can be made.
Antenna placement
If the antennas are directly connected to each receiver, make sure that the units are placed at or near line-of-sight with the location where the transmitters are being used--and avoid placing them behind architectural blocking elements like walls whenever possible. If you are using remote antennas and a multicoupler to feed multiple receivers, they can be moved closer to the action. Make sure you’re using low-loss antenna cables, and that the cable runs are not overly long.
How many channels?
Generally, the more channels of wireless you’re running, the more complex the task of frequency coordination becomes. The potential for interaction among the various wireless frequencies, and between those frequencies and other RF signals in the environment, rises quickly. And the consideration includes not only the wireless mics, but wireless in-ear monitors, intercoms, AV control systems, WiFi networks (when using 2.4 GHz wireless mic systems), and even in the relatively near future the 600 MHz smartphones that may be scattered in the pews.
If you’re running only a handful of simultaneous channels, such as a pastor headset and a couple of handheld vocal mics for the praise band, just selecting from the pre-coordinated groups of a frequency-agile wireless system should be relatively reliable. But let’s say you’re running a production with half a dozen or more bodypacks, the worship team are wireless, as are several members of the band, with an additional channel or two for input from the congregation. You may run into some problems unless you spend some time sorting out the RF environment. And this is not the place for $100-per-channel wireless.
Wireless systems with scanning capabilities can help by assessing the local RF environment within its designated bandwidth, and taking into account the radio signals it detects when suggesting frequencies (groups/channels) that are most likely to operate without interference. But that’s only part of the picture, and other wireless sources might be active at the time of the service or event that weren’t apparent during rehearsal. If you’re running lots of wireless, either have the hardware/software to regularly assess the situation, or hire someone to do the task.
During your testing, make sure that all of the other transmitting sources, like the wireless intercom, are on so that they can be seen in the scan.
During your testing, make sure that all of the other transmitting sources, like the wireless intercom, are on so that they can be seen in the scan. And that guitarist who brings in his own wireless system just before the service still might throw off that careful coordination--so be prepared.
Adding wireless
If you’re renting additional wireless for a special event, make sure that what you are getting is coordinated with the channels you are regularly running, and for the particular RF environment (local television channels, and more). Provide the company you’re renting from all of the pertinent details to perform the frequency coordination and set the channels. Try it out in your place before the event, to minimize last-minute panic.
Clear 600 MHz spectrum
If you’re still using wireless that operates in this band that was recently sold to telecom companies, it’s time to retire it. In some regions of the country, interfering networks are already being set up--and they have legal priority. Know what’s going on wirelessly in your locality.
Test it out beforehand
Especially if you’re putting on a pageant or other occasional event, introduce the wireless into the rehearsals well before the day of the presentation. Walk the area with each transmitter and listen for dropouts or other problems while setting up for the rehearsal. Make sure each user is comfortable with the wireless transmitter, knows how to position it on their person, and where the microphone element should be placed, or have a knowledgeable assistant help with this process.
Check lavalier and headset cables for any damage that could add noise and crackles during the event--move those cables around during your set up to make sure.
Identify the transmitters and corresponding receivers and mixer channels for each user so they and you know--if the system allows the transmitters and receivers to be named, this is a time to use that capability. Check lavalier and headset cables for any damage that could add noise and crackles during the event--move those cables around during your setup to make sure. The advance work will help eliminate unpleasant surprises.
To sum up, wireless microphones can be a great solution for sound reinforcement. By taking care and preparing in advance, you can enjoy the benefits of wireless while avoiding the hassles.
