Wireless microphones in the field

Today, productions large and small use wireless microphones, in-ear monitors (IEMs) and intercom systems. While smaller events utilizing this equipment are relatively easy to plan and produce, larger ones can become quite challenging.

The professionals who install and operate wireless audio systems for these scenarios have learned how to manage the flow of information and apply proven techniques to the hardware in order to get several wireless systems to work together successfully in the same venue. This task involves many of the same engineering principles one would apply to designing the main PA system or the broadcast signal path.

These principles can be boiled down into a fairly simple recipe: Gather requirements and baseline information about the event, and then design the wireless microphone setup to match.

Setting the scene

One of the most challenging aspects of planning a successful event is determining what you have to work with and what needs to be accomplished. As an example, let’s take a look at planning for a medium to large music awards show.

Several weeks out from the event, the tech manager will ask for a bid. To provide this, the first things you’ll need to determine are the location, dates and requirements for the event. In this case, let’s assume that you’ll be working in a large sports arena in downtown Miami.

The host television network owns a fairly large collection of wireless microphones, IEMs and wireless intercoms. To make the budget stretch further, the host would like to use its equipment for the production, with supplemental equipment to round out the requirements. In addition, there are associated productions, such as a red carpet event, that will also need equipment and coordination. Finally, there will be media crews using wireless systems for both the production and for press coverage.

The main production element has several live-live musical performances and many more live-to-track performances. Meanwhile, some of the artists are endorsed by Brand X, and request specific transmitter models or wish to use their own custom-decorated transmitters.

At this point, you now know what needs to be done, where it needs to be done and when. But you don’t know what you have available or what is required.

The first step is to get a list of equipment and frequency ranges that the television network wants to use. While that list is being compiled, you’ll need to determine the baseline coordination for Miami. This requires figuring out which TV channels are available and which are blocked by broadcast transmissions at that particular venue in Miami. There are several ways of going about this task, such as using a frequency coordination software package, tvfool.com, fccinfo.com or FCC.gov, but all of these methods are based on the same FCC data.

If that information is out of date or contains inaccuracies, you might find that channels you expected to be available are actually in use. That’s why nothing beats an actual site survey for determining the baseline coordination. It’s best if you conduct the survey well in advance of the event, but if that isn’t possible, make it the first task you perform once you arrive on site.

For planning purposes, however, you next need to determine what equipment the performances require. As it’s common for some of the acts not to send their riders until much closer to the production itself, it’s important to look for frequency ranges that overlap across multiple different wireless vendors and equipment models. This way, you can reserve additional frequencies for those making last-minute additions.

It’s also important to work with the intercom department, as its goals and restrictions often differ from those of the audio department. For instance, the tech manager may be asking for additional wireless channels for riggers flying set pieces into the stage, while the A1 or producers want more mics and IEMs for a performance element that was just added.

Deployment

Once you have the list of required equipment and have determined the baseline coordination, it’s time to start fitting the puzzle pieces together.

First, integrate the “must-use” equipment from the network and baseline coordination. Once you complete this task, you can fill in the middle of the puzzle with equipment from your inventory. Sometimes, there is simply too many of one particular model and frequency range, and you have to look at subrenting equipment in alternate frequency ranges. Only after the frequency coordination has been roughed in can you start designing an antenna system and accessories to outfit the required coverage areas with all of the various wireless systems needed for this production.

While you are planning, maintain your awareness of the other productions going on in the area, such as the red carpet event or the daily network news show. These other events need to be mixed into the overall frequency plan. It’s pretty much guaranteed that the talent and production staff will be in rehearsals or on-air at the same time that the main event is rehearsing.

An added twist comes in the form of roving camera crews documenting the event setup or shooting B-roll packages for use during the broadcast. As these crews routinely shoot both inside the main event and at each of the associated productions, their wireless mics need to be coordinated for use both inside and outside the venue. Don’t rely on those crews remembering to change frequencies when they move from one area to another.

Once on site, program all of the wireless systems to the frequency plan you developed, and “war game” all of the systems. War gaming refers to turning all transmitters on at once, and then turning one off at a time and checking the associated receiver for any issues.

When all of the fixed systems are working to your expectations, it’s important to identify the roaming wireless systems in some manner. We often put a flag or tag on the receiver antenna showing that a camera crew’s wireless mics have been cleared for use. This allows anyone in the audio or intercom department to quickly determine if a new system has been brought into the venue or a previously cleared system is in use. If anyone on the crew spots wireless systems without flags, they are trained to contact the lead frequency coordinator. This way, the new wireless system can either be cleared for use or requested to be turned off.

Show time

On the day of the event, many more media crews will show up to cover it, and many of these crews will bring wireless systems. It’s important to constantly watch for these new arrivals and intercept them before they start using their wireless systems. If possible, try to clear the frequencies for use and be sure to flag the systems for quick identification. If the systems cannot be cleared for use, ask the camera operator to remove the antennas completely to show that they aren’t using the wireless systems at all.

Prior planning is key in the wireless microphone game. Learning the recipe for success and being able to apply it before and during the event will help you produce every event with zero wireless problems.

Jason Eskew is a wireless specialist with Professional Wireless Systems and the author of the Intermodulation Analysis System frequency coordination software.