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Wireless Mic Systems Seek Frequencies Not Frequently Used

Producers of these systems may need to include scanners that look at the local spectrum to provide a clear signal.

Electro-Voice’s RE-2
As the frequency space for wireless microphones further shrinks, producers of those microphone systems say those products need to have frequency scanners that look at the local spectrum to find an open frequency that provides a microphone with a clear signal.

by J.J. Smith

Federal Communication Commission rules limit wireless microphone broadcasts to unused television channels of from 470 megahertz up to 698 megahertz. However, those frequencies are also opened up to other communications devices which do not require licenses, increasing the possibility of a those devices interfering with a wireless microphone system, says Steve Savanyu, Audio-Technica’s director of educational services.

“As the wireless situation evolves, users have to be more careful than ever before to avoid being interfered with by other devices that are out there,” Savanyu said. “In some parts of the country it’s very difficult to find a useable frequency, so producers need to be aware of that when planning on using a wireless microphone,” he said. Because the airwaves are getting more crowed with broadcast from other communications devices that use the same TV bandwidths, the situation is “going to get worse,” he added.

Audio-Technica’s 1800 Series AUDIO-TECHNICA’S 1800 SERIES

Savanyu says Audio-Technica’s 1800 series wireless microphone system is a traditional UHF wireless—with a body pack transmitter—and a scanner. The 1800 series also has a dual-channel receiver that provides “two complete independent wireless systems in a single package,” he says. The system runs on six, AA batteries, and it can mount to some of the larger cameras. “For the producer who is doing corporate/government videos, this is a convenient way to do two channels of wireless without having to carry two completely separate systems,” he said.

Therefore, users are doing what they can to find open and useable frequencies, with the equipment they have, Savanyu said. Nonetheless, video crews should always carry a 30-foot microphone cable with them, because it is usually not known if a wireless microphone can be used at a location until a crew arrives there, he said.


To keep from being interfered with during a broadcast, users need to research which spectrum is clear at their locations, and the best wireless microphone systems will have some form of scanner, says Dave Egenberger product manager for Electro-Voice Wireless Microphones. The job of a wireless microphone is to be invisible, and act like a wired microphone, and “provide wired microphone quality audio,” which is why scanning the spectrum is important, he adds.

Lectronsonics’ SR Receiver

Sennheiser Electronic Corp.’s EM-3732 Receiver
Egenberger says Electro-Voice’s RE-2 wireless microphone system is the company’s “most flexible and affordable product.” The RE-2 has a 28-megahertz bandwidth over six TV channels, “so it works a few channels everywhere,” he says. In addition, users have some options for body packs, including the RE-2 pro, which has a drop in recharger, and adjustable transmit power, so if there is a need for a little bit more range, users “can bump up the transmit power to 50 milliwatts.” The RE-2 “also has excellent audio quality” that is “close to wired microphone audio quality, he said.


Sennheiser Electronic Corp.’s SKM 5200 There are two key attributes that differentiate wireless systems, says Kevin Waehner, product specialist for Sennheiser Electronic Corp. The first is switching bandwidth, which means the tuning range of the units in question; “how many frequencies can they be tuned to?” he says. But the most important aspect of a wireless microphone system is the quality of the capsules, he said. Sennheiser’s “flagship” handheld wireless microphone is the SKM 5200, which not only has wide switching bandwidth, but it also a “broad range of capsules” providing “the best quality sound,” he added.

Along with the SKM 5200, Sennheiser offers the EM-3732 receiver. The two pieces “make one unit” that provides “the greatest degree of versatility for production to work around” conditions that hinder video production, Waehner said. The system offers “the widest switching bandwidth of up to 168 megahertz in the U.S.” giving users the ability to tune around any source of interference, he said. In addition, producers can choose from “the highest quality capsules” used for audio capture, he said.


Karl Winkler, Lectronsonics’ director of business development, said government video producers and broadcasters are “looking for reliability, ease of use, and an interface that makes sense” from wireless microphone systems. That is why users should focus on the receiver section of the system, he added. Lectronsonics’ SR Receiver is “a dual channel camera mount type receiver,” and it has two channels so two speakers can be picked up simultaneously, he said.

Additional features offered by the SR Receiver include diversity reception, which means it has two antennas to avoid interference and frequency scanning to look at the local spectrum where the shoot is going to occur, and pick the out frequencies that are not being used, Winkler said. Government video producers and broadcasters will find the “SR Receiver is an excellent receiver,” he added.