April 26, 2017

Letters to the Editor, Spring 2017

Dear Editor:

I just read Alan Barker's article "Documentary Sound: Some Minimal Audiokits" (Winter 2017) with some interest. However, there are a few details not mentioned that should influence purchase decisions and subsequent use.

The use of wireless microphones in the field is controversial and not necessarily recommended. In the United States, wireless mics are subject to the rules of FCC Part 90, and may require licensing, registration and frequency coordination—particularly in high-density urban areas where the risk of interference is high. If you are using a wireless mic in a rural area, you may never encounter any problems. Other countries will have different rules, so it is best to check before you take a wireless mic overseas.

Wireless transmissions can be a real issue in a combat zone. Embedded reporters need to coordinate with unit commanders to ensure that gear will not compromise operations. Direction-finding equipment can quickly pinpoint the location of a reporter using a wireless mic; opposition forces do not care that the reporter is a non-combatant.

As the FCC comments, "Whenever possible, it is better to use wired microphones." Yes, wires can be clumsy, and they occasionally are damaged (repairs are simple, spares are cheap), but wireless gear is far more fragile and expensive, and batteries are always a worry.

Shotgun mics on cameras are the default for one-person ENG [electronic news gathering] activities where mobility is essential. The mounts supplied by most camera manufacturers are not adequate to support high-end (especially longer) shotgun mics, but it is possible to add a better shockmount to the camera shoe on the top handle of the camera, which will help reduce operator noise and permit the use of a longer mic. (This also has the slight advantage that the mic can be elevated high enough to be aimed down somewhat, rather than straight ahead, but the result is a clumsier rig.)

In our production work, we try to remember the KISS rule (keep it simple & stupid), especially when one (or sometimes two) person(s) must function as both crew and interviewer. Test your gear before you actually need to use it for anything critical. Read the manual first, then get to know how the gear really works by touch. Simulate situations and develop coping strategies going out in the field. No matter how much you spend for gear, money will not replace skill—a good reporter can get better footage out of a second-hand $500 consumer camera than an inexperienced operator with a $10,000 rig fresh out of the box.

—Robin McCain


Alan Barker's response:

Non-professionals do not need a license to use a typical wireless microphone in the US. If they did, karaoke bars would be scenes of mass arrest (which might be a blessing). According to the FCC website page addressing wireless mics, "All users of wireless microphones may operate the equipment on an unlicensed basis, subject to certain restrictions: the device (1) must not be operated at a power level in excess of 50 milliwatts, (2) may not cause harmful interference and (3) must be operated in a way that accepts any interference that may be received.”

The popular Sennheiser SK 100 G3 and the Sony UTX-B03 RF transmitters have power outputs of 30 milliwatts. Professional walkie-talkies, by comparison, typically have power outputs of 4,000 to 5,000 milliwatts.

Only wireless microphones that operate on legal frequencies are sold in the US. You should clear your equipment when traveling to foreign countries, as it is true that some countries ban certain frequencies and some ban all wireless equipment. I had an unpleasant experience with that in the Soviet Union, but I got away. If you travel to the US, be aware that any transmitter broadcasting above 700 mHz is illegal and may be confiscated at customs. It happened to some French friends.

Interference with commercial transmissions is rarely a problem; I have never heard of a case. Wireless microphones used by filmmakers broadcast at such a low-power signal, they interfere only with similarly low-powered nearby transmissions, which are mostly other wireless microphones. In any situation where a wireless microphone might cause a problem, such as a stage performance, motion picture set, hospital or any place where other wireless microphones are being used, frequencies should be coordinated. A well-known filmmaker friend was once mortally embarrassed by having her sound broadcast to a theater audience. Luckily, no bathroom was involved.

Wireless microphones do not use military frequencies; however, you probably will be required to have your equipment approved for use in a military area. Unlike cell and satellite phones, which can be targeted with geolocating technology, targeting a wireless microphone signal requires older radiolocating technology. The signal is too weak to be received distantly, and targeting would require direction-finding equipment in two or more locations for triangulating. If someone can determine your location with this technology, they can probably see you—not a good time to call in artillery.

The advice on equipment choices and techniques is well-intentioned, but reflects the conventional thinking I feel documentary filmmakers need to go beyond. “Shotgun” microphones in particular are generally misunderstood. The use of “shotguns” on-camera when not needed, which is most of the time, has resulted in plenty of bad sound and bad camerawork that chases the sound sources rather than the visual story.

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