Nothing does more to help create professional video than a good, external microphone. The right mike sets your video apart from the birthday-party hobbyist with clarity of sound comparable to the networks.Half the fun of owning a digital video camera is accessorizing. The camera works fine out of the box, but of course, you need tripods, batteries, lights and filters all in the name of better video. While each of these items is a great addition to your video kit, choosing and using the right microphone for your video productions is extremely important.
In recent years, microphone variety, quality and pricing have all improved, offering choices to all videographers regardless of budget. But with such a broad selection, how can you know which microphone is right for you?
Application is Everything
Wouldn’t it be great if there was one all-purpose microphone that worked in every situation? A quick glance at our accompanying buyer’s guide tells us that it isn’t likely. And to complicate matters, equipment manufacturers like to include industry terms, confusing charts and specifications with their microphones. A basic understanding of the most common phrases will keep you out of trouble and furnish you with the knowledge you need to confidently make your microphone purchase.
First, let’s divide the field into the various types of microphones. This also helps us determine the typical applications for these mike types.
Hand-held microphones are the simplest and most common of all the mike types. Hand-held mikes are generally used news-reporter style and offer a straightforward way to improve the audio in your videos. Since the hand-held microphone is frequently visible in the shot, a neutral appearance is important (the Wayne Newton gold-plated edition is probably a bad idea). Depending on your preferred pickup pattern, there is quite a range of products in this category. The Shure SM58CN ($204) is popular for its good sound quality and durability. Electro-Voice also provides two contenders. The RE50 ($256) has served as a workhorse in the news industry for many years and offers an open, natural sound quality.
Lapel microphones offer a more discreet way to pick up sound from your on-screen talent. Often called lavalier or lav mikes, the predecessors to the modern lapel mikes were large, clunky and worn around the neck with a cord. By comparison, today’s lapel microphones are almost microscopic; many are smaller than a pencil eraser. This feature makes it simple to hide the microphone on the talent. Most often clipped to a tie, collar or jacket lapel, these mikes frequently go unnoticed on video. Sony has a good example with its WCS-999 ($150) lapel microphone. Virtually every other microphone manufacturer offers an entry in this category.
If you shoot industrial videos or more film-like productions, shotgun microphone may better suit your conditions. Although shotgun mikes can be hand-held, more often they are mounted on a stand or pole and suspended over the scene, just outside the video frame. Shotgun microphones are the work-horses of the film and television industry for their ease of use and high rejection of ambient noise. No one company owns this category. The Sennheiser MKE 300 ($249) is a popular short shotgun designed specifically for camcorder use. Audio-Technica offers the AT835ST ($899) and AT815b ($399) shotgun microphones, which both provide excellent sound quality, noise rejection and operate on a single AA battery.
The boundary microphone (or PZM) is unique. You don’t hold it, wear it or mount it on a stand. It simply lays on a table or floor. This design turns the entire table or floor into a pickup surface. Boundary mikes are great for boardrooms, legal video and dramatic presentations. They pick up everything, although the increased pickup surface is a double-edged sword. Wanted and unwanted sounds are both collected with equal clarity. When using a boundary microphone, make sure the ambient noise level in the room isn’t so high that it obscures the sound you want to record. Crown International invented this category with its PZM or pressure zone microphone. In fact, the PZM name is so synonymous with boundary mikes, it’s almost become a generic term. Of course, many other manufacturers offer boundary microphones, ranging from the simplicity of Audio-Technica’s AT851a ($297) to the portability of AKG’s C 562BL ($712).
The final microphone category, the studio-style stand mike, is specifically for studio recording, not field production with your camcorder. If you record voiceovers, narrations or sound effects on a regular basis, there are many affordable studio microphone choices. Most of these mikes use the "side address" system, where you speak into the side of the microphone, instead of the top. Many employ a large diaphragm pickup element optimized for accurate reproduction of the subtlest of sounds. Examples in this category, are the RODE NT1 ($349) and the AKG C 2000B ($378).
A microphone’s pickup pattern determines from which direction it is most sensitive to sound. The omnidirectional pattern picks up sound equally from all directions. Most lapel microphones are omnidirectional as well as many hand-held models. Because the omni doesn’t discriminate against the direction of the sound, it’s great for conveying a sense of the surroundings in a video. But it’s also easy to bury the sound of a soft voice with ambient sounds such as traffic noise.
The unidirectional or cardioid pickup pattern is popular for its ability to minimize external sounds and focus on the person speaking. The term "cardioid" comes from the shape of the microphone’s pickup pattern, similar to an upside-down heart. This pattern allows the mike to pick up sound primarily from the front, with some pickup on the sides and almost no pickup at the rear of the microphone. There are several variants on the unidirectional pattern. The supercardioid pattern is simply tighter, reducing the pickup from the sides. Hypercardioid mikes are more extreme, with almost no pickup on the sides. The shotgun microphone is still more aggressive, with a pickup area so tight it resembles a long, skinny balloon.
The bi-directional or Figure 8 pattern looks like the number 8 turned on its side. This type of mike picks up sound only from the sides, with no pickup from the front or rear of the microphone. This is a specialty pattern and is commonly used in MS miking (see Stereo Recording Techniques, Videomaker Nov. 2001) and other unique situations. Many boundary microphones have a half-omni or hemispheric pattern, which looks like a ball, cut in half. Other boundary mikes have a more directional pickup that reduces sound pickup from the rear of the mike.
Independent of type or pattern, a microphone’s element determines the quality and application of the mike. The dynamic element is a robust design, well suited to rough handling. Typically found in hand-held microphones, the dynamic element requires no external power supply and works well in a wide range of temperature and humidity conditions.
The condenser microphone is a bit more delicate and often finds its way into lapel mike designs. These mikes require a power source of some type, which can be anything from a AA battery to mixer-supplied phantom power.
Ribbon microphones are fairly rare, especially in the video arena. Ribbon mikes are prized for their smooth sound quality, but tend to be a bit fragile.
In addition to the microphone element, there is the issue of balanced versus unbalanced connections. The Balancing Act article in this issue of Videomaker has more information on the subject, but here are the basics. Unbalanced connections use two conductors, a signal wire and a ground to transfer the signal from the microphone to the camera. This system works fine in many situations, as long as the cable length doesn’t exceed 25 feet and you aren’t shooting near a radio station. Balanced connections use three wires: a positive signal, a negative signal and a ground connection. This method is far less prone to interference and allows for long microphone cables, 100 feet or more. Unfortunately, virtually all camcorders offer only unbalanced connections, usually with a simple 1/8-inch connector. Through the use of some readily available adapters, you can attach virtually any microphone to your camcorder, realizing the benefits of professional equipment.
Wireless mikes are completely different animals. Not because they sound different or work different, but because they are different. Instead of a simple microphone and cable, you have to deal with transmitters, receivers, batteries and frequencies. A wireless transmitter couples a microphone (your choice) to a radio transmitter on a specific frequency, usually VHF or UHF. The wireless receiver picks up the signal from the transmitter and relays it to your camcorder.
Wireless seems convenient from the talent standpoint; no wires or cables to deal with. But things get more complicated on the receiver end. You’ll need a place to mount the receiver, along with a power source (if it doesn’t use standard battery power) and, of course, cables and adapters to connect to your camera. If this seems like a lot of trouble, it is. But the convenience of wireless may outweigh any extra inconvenience.
The Final Analysis
There’s nothing like having the right tool for the job and microphones are no exception. Before you buy, consider how you will use the microphone, including the environment and the type of video. Weigh cost against convenience and quality. If possible, try various microphones with your camcorder. This will prove how simple they are to attach and manage. Record some sample audio with your camera and take it back to your editing system. Comparing the audio from each mike may help with a difficult decision. Remember, an investment in a quality microphone equals an investment in quality video.
Making the Connection
Some microphones are designed specifically for attaching to camcorders. Unfortunately, they are in the minority. However, a trip to your local electronics store will uncover a wide assortment of audio adapters to simplify hookup. Keep in mind, most (if not all) camcorders provide a stereo 1/8-inch jack for plugging in external microphones. If you’re using a single microphone, this means not only adapting from the connector on the mike, but also adapting the mono output to a stereo connection. See Feed Me! in Videomaker‘s Oct. 2001 issue, for more information.