089 – Radio Frequency Coordination

The wireless audio landscape is changing year by year, which makes the job of an RF (Radio Frequency) coordinator increasingly important.

Written by Scott Adamson

Wireless audio is super cool technology, and it's become an integral part of live music (and theater) productions. You can look at any big festival stage and see antennas set up everywhere to accommodate all the wireless mics and IEMs. These are huge part of many touring productions these days and the number of channels we need to have a successful show can grow quickly.

For example, a Country / Rock / Pop band could have six members, each with stereo IEMs. Add a few wireless mics and maybe a wireless guitar, and you're quickly getting to the point where managing all these frequencies becomes a fairly complicated job. After all, if any of these channels are getting interference, it can seriously interrupt a performance.

What makes it worse is that the frequency range that we use for wireless audio is shrinking year by year. Mobile phone carriers operate around the same part of the frequency spectrum, and they have been lobbying hard to get more and more access to the frequencies that we use. The agencies that regulate this all around the world have been granting that access with little regard to how it affects us in the audio world.

At big festivals, where multiple artists for any given stage could have 10 + channels of wireless, a dedicated frequency coordinator will monitor the frequency spectrum and assign very specific frequencies to each artist. This is the best way to make sure everyone has what they need for their show.

But there are other concerns. Even if you have enough frequencies for all your wireless channels, you still need to make sure those frequencies will work together. Using multiple frequencies in a wireless system causes intermodulation, which creates ghost signals that can interfere with other frequencies.

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Luckily, intermodulation is predictable and a frequency coordinator can use tools, like Shure’s Wireless Workbench or RF Venue’s Explorer RackPRO, to make sure none of the signals are stepping on each other and causing dropouts. And even if you don’t have these advanced tools, professional wireless systems have preset groups of frequencies that are okay to use at the same time (called “groups” by Shure and “banks” by Sennheiser).

The wireless audio field is changing rapidly and RF Specialists are in high demand at live events, not only in music but in other areas like professional sports. If you're an audio engineer looking to specialize in something that can potentially lead to higher paying jobs, this is a great avenue to consider.