Audio Global Viewpoint – April 2018

Where Lavalier Microphones Fit and Don’t Fit in Video Recording

There are many, many choices of microphones available for video recording — from lavaliers to shotguns to on camera-mounted mics. How do you choose the right mic for the given situation. Here’s a guide.

Since microphone models are constantly changing, we are citing a recently study by Transom.org, a Peabody Award-winning website dedicated to aiding the storytelling process with new media. The organization, which instructs journalists on gear choices, tested mics from $20 to about $500, including wired, wireless, smart phone/tablet lavs and the new breed of stand-alone lav recorders which have great application in rough-and-tumble recording scenarios, like extreme sports.

The sight of a microphone in front of a person's face can be intimidating to the inexperienced.

The sight of a microphone in front of a person's face can be intimidating to the inexperienced.

For many years, Transom said it has avoided recommending lavalier mics as interview mics due to sonic compromises that were not worth the benefits. Now, in its latest study, the group suggests with new types of media recording there are times when a lavalier may be the right tool for the job if cautions are used.

Lavs might give the best sound if an interviewee is on-camera and needs to move around, making it hard to use a boom shotgun mic, the recommended microphone type. Also, new devices have also made lavalier recording more practical and affordable.

While lavalier microphones are often the first 'go-to' solution, use caution because proper positioning is critical for best sound pickup.

While lavalier microphones are often the first 'go-to' solution, use caution because proper positioning is critical for best sound pickup.

Lavs help nervous interview subjects become less intimidated by a mic they can’t see. However, using these mics also can present problems, like being in a less than ideal position. For example, when using a boom or even a handheld mic, it should never be placed flush against the interviewee’s chest, on their lapel, behind a tie or up in their hair.

Those positions don’t result in the best vocal sound. It can be echoey, hollow, muffled or brittle, the study found. Because the mic is stationary, the subject’s head movement can cause the voice volume and timbre to shift. Lavs with an omnidirectional pick-up pattern result in a more even pick-up, but also record more room ambience and noise.

If a lav does seem like a good solution, the range of price and quality is vast. Lavs can be used different ways. One is a traditional wired microphone using either an XLR or mini cable (DPA, Sennheiser, Shure, Sanken, Audio-Technica), or with wireless transmitters and receivers, self-contained lavalier recorders (Zoom, Tascam) or as a smartphone or tablet-based microphones (Rode, Sennheiser).

A lavalier microphone, also known as a lapel mic, lav, clip mic, body mic, collar mic and neck mic, is a miniature microphone, most often placed somewhere on the talent’s body. One advantage is that they allow the talent to move freely while they are performing.  Shown: DPA lavalier.

A lavalier microphone, also known as a lapel mic, lav, clip mic, body mic, collar mic and neck mic, is a miniature microphone, most often placed somewhere on the talent’s body. One advantage is that they allow the talent to move freely while they are performing. Shown: DPA lavalier.

A simple solution is usually the best. A basic omni-directional lav mic on an XLR cable introduces the fewest complications. Mics with an XLR connector rather than an ⅛-inch mini connector are more reliable. Avoid cardioid lavs for recording. They are best for live events where the mic is being amplified through sound reinforcement. With omni lavs, there are no battery or interference issues such as those found with wireless mics, and users can monitor the audio levels effectively at the recorder.

Even with an omni mic, users need to take care to avoid anything rubbing against or banging into the microphone. Mics can be clipped directly to a shirt or coat lapel, but users may also need to secure the cable and other clothing or jewelry that could create noise. Sound engineers often make a loop in the cable at the mic end, to provide some strain relief and reduce noise from the cable getting inadvertently tugged.

Some engineers like to clip lavs pointing downward, which can help reduce an overly-bright sound and mitigate breath sounds hitting the mic element. In theory, omni-directional mics should sound the same regardless of orientation, but in the real world all have some directionality, especially in high frequencies.

Many lower priced lavs require “plug-in power,” which is a small current, commonly provided by many recorders and video camcorders. It is NOT the same as phantom power, although it serves a similar function. Some of these mics have their own batteries.

The Sennheiser G4 wireless microphone system is easy to use and provides professional results.

The Sennheiser G4 wireless microphone system is easy to use and provides professional results.

Wireless lavs are an increasingly popular option. But there are a few downsides too. The first is cost. Expect to pay more for a high-quality, name-brand wireless mic. Regardless of expense, however, a wireless system adds more layers of complexity and potential for problems.

There are batteries in both the wireless transistor and receiver, which you have to make sure remain charged, in addition to the batteries in your recorder. Wireless signals are susceptible to radio interference, and even without conflicting signals, wireless systems can suffer from background noise. Radio transmitters and receivers will add some noise too, compared to a simple wired microphone.

In many cases, a small amount of added hiss is an acceptable trade-off for the freedom allowed by a wireless connection. In certain environments, that noise might not even be audible. But there’s usually a little noise and the user will have to decide if it’s too much.

Also be careful of buying use wireless gear. The Federal Communications Commission (FCC) has changed the rules on what frequencies are available for wireless devices. Make sure you are aware of the rules before purchasing a used system. If the system is too cheap, you can guess why.

The Zoom F1 System has a small profile and attaches neatly on belts, waistbands, or slipped into a pocket so the recorder can be easily concealed.

The Zoom F1 System has a small profile and attaches neatly on belts, waistbands, or slipped into a pocket so the recorder can be easily concealed.

The latest type of lavalier system involves a microphone connected directly to a small recorder, which can be placed in a pocket or clipped to a belt. It is used like a wireless transmitter. This removes many of the problems of wireless systems. There are no wireless connection problems, half the number of devices and batteries and reduced cost.

The major problem with these kinds of devices is that they violate one of the golden rules of audio engineering. That is you must always monitor your recordings. These tiny recorders have headphone jacks that can be used when setting up and testing levels, but during the actual recording the users will have to go on faith that the levels have been set properly.

Thanks to manufacturers, the levels issue is not a difficult problem. Combined with the built-in limiter and the option of dual recording (which records a second track at a reduced level), it’s not hard to get a usable level on these new recorders. The screens are tiny, and provides only the bare essentials for setting up the recorder. But it does offer enough feedback to make usable recordings.

The major problem with this kind of recorder is that lavs are inherently susceptible to sounds from rustling clothes, the subject touching the mic or cable or wind and breath noises. Because it’s not possible to monitor the recording in real-time, users won’t know if those noises have interfered with the recording until after it’s done.

The Sennheiser ClipMic Digital clips to clothing and features an Apple Lightning connection and a high-quality external signal converter to produce broadcast-quality recordings to an iPhone or iPad.

The Sennheiser ClipMic Digital clips to clothing and features an Apple Lightning connection and a high-quality external signal converter to produce broadcast-quality recordings to an iPhone or iPad.

There is a lot of interest in recording directly to smartphones and tablets. But be careful of the device used. Some had mic connectors and newer iPhones use lightning connectors. For newer iOS devices, there are some lavs — such as the Sennheiser ClipMic Digital — that connect directly to the lightning input of an iPhone or iPad. This can can be used like a small recorder.

The convenience of smartphone recording is hard to deny, especially if the users needs to send the recording to another location quickly. But it’s still worth remembering that a dedicated audio recorder has many advantages because smartphone apps are more likely to crash than a dedicated recorder, phone batteries are notorious for running out prematurely and it’s easy to fill up a phone or tablet’s internal memory without realizing it.

While today's lavalier microphones are better than ever and the results can be quite good, they are not the

While today's lavalier microphones are better than ever and the results can be quite good, they are not the "MacGyver tool" for all applications.

Lavs, Transom found, can be a handy tool in many circumstances and it is good to have one or more in your sound kit. But in the end, the engineer should ask himself whether a lavalier is needed rather than the standard boom-mounted shotgun or hand mic. If not necessary, the answer should be go with a more conventional mic, placed in front of your subject’s mouth, rather than a lavalier clipped to their clothes.

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