Martha Smith

The Wanna-Have's:
Radio Mics

I used to carry two 25-foot XLR cables to connect mics far away from the camera. Today, I carry a couple of wireless systems. They’re not lighter than 50 feet of XLR cable, they’re just more convenient.

Let’s talk about the great example Amy Bowers gave at the Platypus Workshop in Oklahoma City. There’s a fresco-restorer working close to the ceiling on a scaffold; you want to get the “effects” audio to match the picture of the restoration (tap, tap, brush, brush). You can put a mic on the scaffold next to the restorer, and run a long cable down the scaffold (concealing the cable behind the pipes so it’s not apparent in the shot). Or, you could send the signal via wireless. A wireless connection allows the cameraperson to move around the scaffold, to get a variety of shots, without the possibility of tripping over or seeing a mic cable. In this instance, a wireless audio feed is quite convenient.

Even though wireless systems usually come with dedicated lavaliers, the beauty of the system is that you can send a radio signal from any kind of mic. If the scaffold is 12” away from the ceiling, with the restorer lying on his back, tape the dedicated lavalier onto something you control (like a Rowi clamp or the gaffer tape roll), and place it next to the restorer. (Don’t put the lav on the restorer because you’ll get clothing movement noises which will obscure the sounds coming from the ceiling.) If your aim is to also pick up the restorer’s murmurings or comments, don’t worry, the nearby lav will pick up voice as well. If the scaffold is 24” or more away from the ceiling, and the restorer is crouching or sitting, a short shotgun mounted to the Rowi clamp placed close to the restorer, with the tip pointed toward the ceiling work area, is a better choice than the lavalier. The shotgun will pick up the restorer’s words in addition to the audio effects from the ceiling work quite nicely. And, by using a wireless transmitter, you can send the either mic signal to the camera without that long cable.

I use wireless systems 70% of the time in situations where there is a stationary microphone, but where long cable runs are inconvenient or would pose a hazard to foot traffic. I use them on podiums, in mult-boxes, out of mixing boards, next to the violin section. But what about non-stationary mics? The classic use of the lav/wireless transmitter is to acquire the audio of a person going about their daily life and work. It’s really the only way to get a subject’s audio without crowding them all the time, or having them play to the camera.

Wireless systems are a big investment, so I rented two systems before I bought any. I was working on a story about a small hotel which had a “Murder Mystery Weekend” (where actors are hired to play murderers/victims and the guests have to figure out whodunnit). I used one wireless system in the classic way, to mike the actor or guest we were following at any given moment. I put the other system at the notice board around which guests gathered to obtain new clues. I just taped the lav to the top of the board (pointed down), and taped the transmitter on the back of the board. (I found out later that people didn’t even notice it was there.) What this system did for me was to provide a constant source of audio (guests gathered around the board), no matter where the camera was. Cameraman Steve could shoot from the next room, or outside, and the audio would still be there. Long shots, close ups. It was great. For me, the best part was evesdropping on conversations when we weren’t rolling tape, to get information on which room everyone was heading to next, so we could get there first.

What I discovered during that weekend experiment, was that the wireless mics I rented worked great at doing what wireless systems are supposed to do-- get the audio from a person who’s on the move and ignoring the camera. But the clincher for me was getting the audio from people gathered around the notice board, because that system picked up audio I couldn’t have gotten any other way. Priceless. Well, $5000 (1982) of my hard-earned money went to buy two systems. I now own four wireless systems, but I rarely ever use more than one in the classic way. The others I use constantly to dot the landscape with mics to collect interesting sounds which would be difficult to pick up otherwise. I’ll gaffer tape a lav and transmitter to the interior wall of a dressing room when we follow someone trying on new clothes. I’ll gaffer tape a lav and transmitter to a desk of a first-grader whom the school superintendant is stopping by to see. (By favoring the child’s voice with the mic, you’ll obtain a good mix of both voices).

A team at the Platypus Workshop in Oklahoma City shot and edited a story about a tattoo parlor. The camera was not allowed in the room where the tattoo was being applied, although the cameraperson could shoot through an interior window. After viewing the edited piece, the team asked me how they could have placed a mic in the room for “presence”. As I recall, they had a hard-wired lavalier, and a short shotgun mic on the camera. The first idea I had was to put the lav in the room, gaffer taped to the far side of the tattoo platform (on the far side because it’s out of the shot, and it’s not in the path of the tattooer who might lean on it and cover it up). The team had a capsule lavalier, which is a cylinder with the audio-sensitive portion on top. To place it, you’d put a little wad of gaffer tape on one side of the cylinder, and tape it in location (in this case, a gurney) with the top of the mic flush or a little higher than the gurney’s surface. Be careful not to put the lav where it’s going to get covered with fabric or hit by a flying limb. By locating the mic close to the head of the tattooee, you’ll pick up that person’s voice, and you’ll also get the tattooer’voice too, since you figure that the tattooer will turn his/her head toward the tatooee (and, therefore, the mic) when they speak.

The other option would be to hang the short shotgun overhead, just above the wide-shot frame line. I’ve always just dangled mics on cables, without mounts. (I would recommend this only if you’re using professional mic cable and heavy-duty connectors.) Anytime you hang a mic, your cable is going to form a right angle (going from horizontal along the ceiling to being vertical as the mic dangles). In this case, make certain that the right angle in the cable is a U instead of a V. You can guide the cable into a U with gaffers tape, or you can use the tape to form a loop at the transition point. For hanging things, I always carry shoe laces and those metal pinch-to-open shower curtain hangers. You can run a cable overhead on shower curtain hangers attached to the metal grid in a drop ceiling, or you can tie cables out of the way with the laces.

If the Platypus team had had a wireless mic system, they might have placed the lav/transmitter on the tattooer. But then you would get only the tattooer’s point-of-view audio, approptiate for an instructional piece, but not necessarily right for a general story about tattooing. So, in this instance, I would use a stationary mic which gathers audio of the whole room, and use the wireless system as a convenient transmission vehicle. If you’re using a lav/transmitter close to the tattoo procedure, use gaffer tape to secure the transmitter next to the mic. For the hanging shotgun, you can put the transmitter overhead as well. Transmitters all come with clips; I loop shoelaces through the clips and just tie them off somewhere convenient. Speaking of transmittter clips, I also carry wide pieces of elastic for transmitters to get clipped on to, when they have to go around someone’s waist under clothes (many women who go on camera for the first time wear their best dress, which means the convenient transmitter location is around the waist under the dress). I also carry medical tape for anchoring lavalier microphone cables to skin and clothes--it’s kinder than gaffers tape, and unaffected by sweat.

These days, a good wireless system can cost as little as $600, and will be more versatile than those ancient models. In the old days (up ‘til about ‘98), wireless systems operated on only one dedicated frequency. These days, good wireless systems are manufactured with the ability to be tuned to multiple frequencies. They are “frequency facile” (to use Holly Sweet’s wonderful description), and these multi-frequency systems are the only type you should be looking at. As the world goes increasingly wireless, the ability to tune your transmitter/receiver to an alternate frequency will become increasingly important. An additional advantage to users is the ability to tune two receivers to the same transmitter frequency, which means you are able to mike a subject once with a lav/transmitter, but send the audio to multiple cameras. (In the old days of single frequency wireless systems, getting subject audio to more than one camera was a real pain.)

I tested a couple of frequency facile systems-- here’s what I found out. Sennheiser’s Evolution Wireless 100 system is quite amazing for the price ($450). I also tested Sennehriser’s Evolution Wireless 500 system, and Lectrosonics’ UM/UCR 100 system (each around $1000). When I buy a wireless system, I look at four things: the sound (and look) of the dedicated lavalier, the distance between a transmitter and receiver where the audio is still clean (called “range”), the size of the transmitter/receiver, and the price.

Sennheiser has two Evolution Wireless systems (100 and 500 series) which have “belt-pack” transmitters/receivers. The “belt-packs” are each 4.5 x 2.5 x 1 inch, and each 100 and 500 series system comes with a very good dedicated ME2 lavalier. This lav is an omnidirectional capsule mic, black, quite small, and sounds just fine. The differences between the 100 and 500 series are in price, range, and unbalanced vs. balanced output. The 100 series (actually 112 when it’s configured with the belt-pack transmitter, and the ME2 lav) has an unbalanced output. The equivalent 512 has a balanced output. You’ll remember from a previous discussion that the engineers say that unbalanced/balanced output becomes an important issue in long cable runs. Since the standard use of a receiver is with a short cable, an unbalanced output shouldn’t be troubling. The other important unbalanced/balanced issue is a consumer vs. professional approach toward manufacturing audio products. Videosmith’s engineer, Nick, says he doesn’t worry about a company like Sennheiser or Lectrosonics making unbalanced connections because they have a proven track record of making good, professional, audio products. The only non-price difference I noted between the 112 and the 512 was in the range.

Range is the distance between the transmitter and receiver, where the audio is clean (free of hissing, buzzing, drop-outs). Range is what you buy a wireless system for. Range is affected by many factors. Most manufacturers will tell you you must have “line-of-sight” between transmitter and receiver; they tell you to beware of operating in electromagnetic force fields, and to beware of large metal objects around the transmitter or receiver. Buyers will ask how far you can get the transmitter from the receiver (“what’s the range?”). Manufacturers will often answer that question in football-field yardage (that line-of-sight idea), to illustrate range. Football field yardage doesn’t make sense to me. I grew up in a section of Pennsylvania with a large German population, so my high school played soccer instead of football. I don’t speak football-field distance. My definition of acceptable range is the distance at which the cameraperson can just barely detect the subject’s lips moving. How many first downs is that? It probably depends on the size of the lens.

At our Videosmith office, I have a standard test of wireless mic range. It involves a straight line between transmitter and receiver, but with large metal objects and possibly electromagnetic fields in between. I try to make wireless systems fail, and I’m pleasantly surprised when they don’t. In my test, I put the transmitter and dedicated lav next to our office boombox, walk past the dolly tracks and the C-stands, through the retail area, and out the front door into the parking lot, listening on headsets to the audio at the reciever end, while dodging moving vehicles. I try to get to the tree in the second row of parked cars with reasonably clean (only a drop-out or two) audio. If this happens, the system passes my range test. I don’t know how many yards this is, but it’s farther than any cameraperson could EVER see the subject’s lips moving. A truly amazing wireless system will have clean audio all the way back to the I-95 wall, through five more rows of parked cars. (Cameraman Steve says the distance from the boombox to the I-95 wall is about 75 yards).

Some systems are truly amazing. Sennheiser’s EW512 was one of them; I couldn’t get it to fail my test of range. The EW112 system passed my standard to-the-tree test and then some before the signal started to break up. The Lectrosonics’ UM/UCR 100 system also passed my standard test, but when you factor in the Lectrosonics’ price at $1000, the EW112 would seem a better buy. And that may be true. But in my small part of the audio world, Lectrosonics wireless systems are the standard by which others are judged. Rugged, reliable, good service, nice folks. I”m not saying that the Sennheiser EW112 system doesn’t compare favorably. I’m just saying that it doesn’t have a track record yet.

Lectrosonics’ UM/UCR 100 system is a wonderful product. If you have $1000 to spend, it’s worth every penny. The transmitter/receivers are slightly smaller than Sennheiser’s, at 3 x 2.5 x .75 inch. The dedicated lavalier looks and sounds just fine; it’s small, black, omnidirectional. I set up Sennheiser’s transmitter/lav, next to Lectrosonics’ transmitter/lav at our office boombox and listened to them in a side-by-side test. They each handled the radio speaker sound all right, as well as the voices of Videosmith employees passing by as they went about their work. Neither mic handled the annoying sound of heavy cases being dragged across the floor without distortion. But why on earth would you choose to mike heavy cases being dragged across the floor with a av? For that job, choose a short shotgun or your wonderful 635A. This brings me to a crucial point.

There’s no reason to buy a wireless system if you can’t use mics other than the dedicated lav. Plan to buy an XLR cable wired to the transmitter input. This allows you to use another mic if something goes wrong with the dedicated lav, and it also allows you to use an alternate mic. Sennheiser and Lectrosonics each sell cables for this purpose for about $25. And plan to buy cables which allow you to take the receiver output into a XLR input, like the Beachtek DXA or the PD-150’s mic inputs. And, for the Sennheiser system, plan to buy two extra antennas (at $11.50 each). The Lectrosonics transmitter/receiver have antennas which are permanently affixed; the Sennheiser’s antennas screw in. Trust me--you’ll lose one. And trust me--your wireless system won’t work without antennas.

In my opinion, Sennheiser’s EW100 system really packs a punch for its price. While I can envision a situation where you’d need the extraordinary range an EW 500 system supplies, the 112 has a range which should meet 98% of your needs. Lectrosonics wireless systems have proved their rugged reliability in the field over the years. I’m hoping the Sennheiser system proves equally rugged and reliable. I’m sure some of you will be buying Sennheiser’s EW112, and I’ll be interested in hearing your field reports.

Martha Smith
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