Sound Track: Microphone Types (page 2)

Whether you choose either a dynamic or condenser microphone, you must also decide the best pickup pattern for your production. There are four primary pickup patterns to choose from: omnidirectional, cardioid (or unidirectional), hypercardioid (or shotgun) and bidirectional (see Figure 3).

The omnidirectional microphone picks up sound in every directionfront, back and sides (see Figure 3a). This microphone is good if the sound source comes from a wide variety of directions and is moving from one side to another in front of the mike.

The cardioid or unidirectional microphone picks up sound primarily in a heart shape from the front of the microphone, including a little from the sides, but does not pick up from the back . This pickup pattern is excellent for voice mikes and miking musical instruments.

The hypercardioid microphone picks up only sound from the front and is very directional (see Figure 3c). You must point it at the sound source to get a good pickup. This type of pick-up pattern is excellent for isolating sound sources like bird calls, individual actors talking in a drama, or isolating one voice in a sea of voices.

The bidirectional microphone picks up sound from two distinct sides of the mike (Figure 3d). You would use a mike with this pickup pattern primarily to record two voices talking into the same microphone. You can also use it as part of the MS Stereo Miking Pattern discussed in last month s Sound Track column.

You can find all of these pickup patterns in a variety of microphone styles. Some of the more expensive microphones even have switches that enable you to choose multiple patterns from a single mike.

After you make the choice between dynamic and condenser, and select an appropriate pickup pattern, you have to choose what style of microphone to use. This choice is entirely dependent on the type of production you are doing and whether or not you want to see the mike on screen. The major types of microphone styles are: handheld, shotgun, lavalier or lapel mike, boundary or PZM (Pressure Zone Microphone) mike and parabolic mike.

The handheld microphone is just that, a microphone that you hold in your hand. This mike is usually flat black or metallic and generally has either an omni-directional or cardioid pickup pattern. It is ideal for direct addresses to the camera by your talent. It looks good and the talent can handle it quite easily. It is the mike of choice for TV news reporters, singers, politicians and talk-show hosts.

The shotgun microphone is a long slender mike that usually has a hypercardioid or even a supercardioid (extremely focused) pickup pattern. You would primarily use this microphone in field production, mounted on a suspension mount at the end of a long fishpole. The boom operator that manipulates the fishpole keeps the microphone out of the frame about 18" from the talents mouth so that they can pick up a consistent voice level. You can use this mike to record sound effects and other sound sources because it picks up sound only from the direction it is pointing, cutting most of the sound from its sides and back.

The lavalier or lapel microphone is a very small microphone that the talent can wear on his or her lapel or some place near his or her mouth. You can hide these microphones in costumes or weave them into an actor s hair. If you ever get bored during a live play or musical, try to find the mikes on the main actors. Costume designers and makeup artists are very ingenious in finding places to hide the mikes and power packs. Lavaliere microphones usually have an omni-directional or cardioid pickup pattern and closely mike a single talent. You can also use the omnidirectional lavalier to mike various acting areas by hiding them in plants, furniture and other set pieces. Just be careful that the talent doesn t touch or bang into their hiding place. You will definitely hear it.

The boundary microphone is a fairly new style of mike that has really made a name for itself lately. This mike is mounted on a flat surface and usually has an omni-directional pickup pattern. These are great for miking conferences where you have a flat table with people sitting all around. You can use them extensively as stage mikes (not placed directly on the stage where footfalls would create heavy interference) to enhance theatre sound levels; or use them to record a group of people in a closed environment like a class or seminar.

The parabolic microphone is for long-distance audio pickup. This extremely directional microphone looks like a small handheld satellite dish which reflects all of the sound to a center-mounted microphone. This mike is primarily used to record the sound at sporting events or to pick up the sounds of wild animals. Both this microphone and the shotgun microphone are ideal for picking up middle to high frequency ranges but are not suitable for high quality, total range sound recording.

As with all equipment, once you find the microphone you want to use, you have to accessorize. A friend of mine who runs a recording studio is constantly explaining the need for the strange looking ring with what looks like panty hose stretched over it. This is an extremely important microphone accessory called a windscreen or more precisely, a pop filter. He places the mesh surface in front of the microphone so that the talents breath does not pop the microphone when they say words with hard "P"s and "Bs.

Windscreens come in a variety of shapes and surfaces. If you ever see a microphone with a gray or other colored foam ball covering its end, you are seeing one type of windscreen.

Another popular windscreen used with shotgun microphones is a zeppelin or blimp (these names coming from their resemblance to the early 1900s aircraft). These windscreens completely enclose the microphone and are attached directly to the fishpole or mike stand. If you see someone using a big hairy microphone outdoors, he is using a blimp with a windjammer cover. This cover is extremely effective when you are shooting in windy conditions.

Shock mounts or suspension mounts, are another extremely valuable microphone accessory. Suspension mounts prevent sounds traveling through the mike stand or fishpole from being picked up by the microphone. Soft elastic materials like rubber or nylon suspend the mike so that the sounds created by your hands rubbing the fishpole or something hitting the mike stand are not heard. It is extremely important that you use a suspension mount when using a shotgun on a fishpole.

When buying microphones and accessories, the kind of equipment you buy will depend on the type of production you do. Look at your needs and compare them with the instruments described above. There is a microphone designed for every type of production. It is up to you to decide what your production requirements are and the microphone that will best fit your audio needs.

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