The Wireless Microphone Challenge

wireless microphones

My production company recently created a corporate video for a client, shooting the project at a golf resort. While shooting skits with the talent out on the golf course, we had to use wireless microphones, as our talent was moving around a lot in each scene. After carefully miking our talent, both my fellow camera operator and I were rewarded with nothing but loud static coming through our headphones. Neither receiver was picking up anything but static. We had neglected to check the frequency allocation charts available at several of the manufacturers’ websites that list the HD broadcast frequency usage in different areas of the U.S., and it was overpowering our mics. That was our first mistake, but realistically, the static we were hearing could have come from any of several local sources. In the end, after more scans and more time delays, we made it work, but it was stressful and the experience wasn’t pleasant.

Due to reallocation of the wireless spectrum, many commonly used wireless frequencies are going away, fast. That’s a big headache for today’s video producers.

The Disappearance Of The 700 MHz Band

For about the past eight years, the Federal Communications Commission (FCC) has prohibited the operation of wireless microphones and similar devices (e.g., wireless intercoms, wireless in-ear monitors, wireless audio instrument links and wireless cueing equipment) in the 700 MHz band, 698 to 806 MHz. This 700 MHz band formerly had been allocated for TV broadcast services and has been repurposed for wireless broadband and public safety services.

Waving Goodbye To The 600 MHz Band

In a quote from the FCC, “In the May 2014 Incentive Auction Report and Order, the FCC adopted rules to implement the broadcast television spectrum incentive auction, which will involve reorganizing the existing television band and repurposing a portion of the UHF television band for new wireless broadband services, which will no longer be available to wireless microphones. This repurposing of the 600 MHz spectrum will, therefore, affect wireless microphone operations across the current TV bands in the future. The impact of repurposing on wireless microphones will not be known because the specific UHF frequencies that are being repurposed for wireless services and no longer available for wireless microphones will not be known.”

In other words, that previously available spectrum is being taken away, and there’s no real plan to make any new spectrum available.

Alternative Wireless Microphone Strategies

The FCC’s statement itself calls into question if and how your 600 MHz UHF wireless microphones may work in any situation now and in the near future. What’s a film or video production user of wireless microphone systems to do? Let’s take a look at some alternative strategies that you can use to make sure that remotely recording film and video sound will continue to be viable for the foreseeable future.

Strategy One: Microphone Systems In The Non-Affected Frequencies

The UHF radio band is defined as consisting of frequencies between 300 MHz and 3 GHz. The bandwidth affected by the FCC mandates of 2010 and 2014 are in the 600 MHz to 800 MHz range. Using wireless microphone systems that aren’t in those frequency ranges should mitigate at least the majority of UHF interference issues, right? Not really. If you look at the big picture, the number of wireless microphone users has increased over the past few years, along with the number of HD broadcasters, and wireless broadband users have massively grown, too. There are more users trying to utilize less available bandwidth; therefore, as we experienced on our shoot, utilizing bandwidth that isn’t in the affected 600 MHz to the now-banned 700 MHz range is no guarantee of interference-free results.

Strategy Two: Remote Recorders

Another viable strategy for some users is to just bypass wireless microphones altogether and use a small, remote recorder. The advantages are lower costs than a wireless system, smaller size and lower battery consumption. The disadvantage is that on some of these smaller recorders, there’s no way to wirelessly monitor the sound. If the mic on the talent is rubbing, there’s cable noise or you experience other undesirable audio problems, you have no way of hearing and correcting it as you shoot.

The Future Of Wireless Microphone Usage In The U.S.

Besides the options we’ve discussed here, there are other potential solutions on the horizon.

Bluetooth 5. What is Bluetooth 5? It’s a newer iteration of existing Bluetooth technology with up to 4x the range, 2x the speed and 8x the broadcasting message capacity of Bluetooth 4.0 devices. As of today, you can purchase a small, consumer-oriented, low-cost Bluetooth wireless system like Sony’s ECMAW4 Wireless Microphone for about $160. Wireless microphone manufacturers aren’t producing pro-level Bluetooth 5 wireless mic systems yet (as the standard was just ratified), but that could change in the future. Bluetooth 5 began rolling out in 2016 and uses the 2.4 GHz spectrum, the same as the RØDE wireless, but the Bluetooth 5 spec, like the RØDE, also allows for Adaptive Frequency Hopping. Stay tuned to see if the pro manufacturers introduce products utilizing the Bluetooth 5 specification.

Get A Part 74 License And Go Digital. If you routinely operate more than 50 channels of wireless (including comms, in-ears and IFB monitoring systems), you’re now eligible to apply for a Part 74 license from the FCC. A Part 74 license gives you two important things: the privilege of using 250mW transmitters and registration on the White Space Database, which entitles you to interference protection from TV Band Devices (TVBD). In the United States, TVBDs are intelligent, fixed or mobile radios that transmit and receive information on unused portions of the TV band, between 54 to 698 MHz—the same frequency range that professional wireless microphones use. They employ a database to determine which frequencies are safe to occupy.

Previously, only film and broadcast professionals could hold Part 74 licenses. In a gesture of goodwill, the FCC has broadened eligibility criteria to include most large-scale wireless audio users. If you use more than 50 devices and want to continue doing so, it’s important to get yourself or your organization licensed as soon as possible. Find out the details here: professionalwireless.com/services/fcc-part-74-licensing/

Non-Affected Frequencies

These systems operate in bandwidth that’s still openly allocated to wireless gear, and so should have minimal interference.

RØDE RØDELink Wireless Filmmaker Kit ($399 retail). The RØDE RØDELink Wireless Microphone System uses a Series II 2.4 GHz digital transmission with 128-bit encryption, constantly monitoring and hopping between frequencies to maintain the strongest possible signal level at a range of up to 100 yards. The 2.4 GHz would seem to be a crowded bandwidth since Internet wireless routers use it and some cordless phone systems as well, but my experience with the RØDE wireless mics, to date, has been impressive with no issues.

wireless microphones

Sennheiser AVX-ME2 ($869.95 retail). The Sennheiser AVX system operates in the much-less-populated 1880 to 1930 MHz range, a much higher frequency and, as of 2017, less crowded than the 300 MHz to 600 MHz frequency range normally used by wireless microphone systems. The AVX-ME2 set includes a body pack transmitter with lavalier microphone, the plug-on receiver and all accessories to operate out of the box with camcorders as well as DSLR cameras. It features self-configuring digital transmission, which eliminates time-consuming radio frequency setup. The ultra-compact receiver rotates around the XLR connector to avoid collision with other devices mounted on your camera. To my ears, the AVX system sounds outstanding, with no frequency scanning required.

wireless microphones

Remote Recorders

Remote recorders take the worry out of wireless, but require more work to sync up the audio and video.

Tascam DR-10L ($199 retail). The Tascam DR-10L is an ultra-compact, convenient digital recorder/lavalier microphone combo. For added flexibility, the included wired lavalier microphone is affixed via a 1/8-inch screw-down lock connector compatible with most Sennheiser lavalier mics and mics with the same connector. I recently picked up one of these as an alternative to my wireless microphone systems in case I’m ever shooting in a location where UHF is just too crowded and problematic to use. The DR-10L uses a single AAA battery and has a tiny but simple and effective OLED screen. It features dual recording, which will record an extra mono channel of audio at a lower level, giving you an alternative track if your main track becomes distorted or overloaded.

wireless microphones

juicedLink Little DARling Distributed Audio Recorder ($265 retail, plus $28 for the optional DARlink RX01 Transmitter). The juicedLink Little DARling shares some of the same features as the Tascam DR-10L, such as dual 16-bit/48 KHz recording. (Although the Tascam DR-10L can also record at 24-bit, the juicedLink unit can only record 16-bit.) But the Little DARling adds the DARlink wireless system, which initiates a slate tone in the recording and output connector to help align multiple DAR audio recordings as well as the video from multiple cameras. The transmitter also solves one of the issues that plagues the Tascam—it can start and stop a recording, a handy feature.

wireless microphones

Zaxcom TRX900LA Series Digital Recording Wireless Transmitter ($1,695 retail). At a much higher cost, if you’re a user of Zaxcom’s wireless systems, the TRX900LA transmitter/recorder represents a way to remotely record and monitor the recording wirelessly, but, of course, at a cost. Each of Zaxcom’s TRX belt packs and camera link transmitters features a built-in two-track time-code recorder. This feature allows the inputted audio to be recorded directly to a removable microSD card. You can use the transmitter as a standalone recorder. So, if you need to record talent for long periods of time or, if they’re going to wander off on their own out of reception range, just wire them up, and you can cleanly capture hours of high-quality time-coded audio. In that situation, you can also optionally shut off the RF transmitter portion and use the TRX in record-only mode to extend the battery life.

wireless microphones

Beyond 2017

It remains to be seen exactly what the future of wireless microphone systems is for film and video production. The good news is, there are many of us who use wireless microphones, and the manufacturers and the FCC understand that the need will always be there for cost-effective methods of transporting sound from talent to recorder. The solutions will continue to change and evolve.

Writer, producer and cinematographer Dan Brockett’s two decades of work in documentary film and behind the scenes for television and feature films have informed his writing about production technology for HDVideoPro Magazine, Digital Photo Pro Magazine and KenStone.net. Visit danbrockett.com

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