One way to dramatically increase the quality of your video productions is by using an external microphone rather than the one that is built into your camcorder. You will be able to get your mic closer to your talent and capture the sharpest, clearest sound possible.
Before you go shopping for a microphone, you need to know, among other things, what type of applications you will be using it for. Will you be doing interviews, voice overs, weddings, or documentaries? The answer to these questions will help you choose the right mic. Once you’ve determined what you’ll be using it for, you will need to decide how much you’ll want to spend.
Getting the Mic Off the Camera
External mics can turn an ordinary video production into one that is colorful and dramatic. Many people take sound for granted, not realizing that there is an easy way to improve it. Mics that don’t live within the camera will do that. By putting them closer to the subject rather than close to the camera allows you to capture a better quality sound, giving you a richer video experience.
The three main types of external mics are the shotgun, the lavalier and the handheld. Each is suited for a different kind of application. Shotgun mics are often mounted onto your camcorder or attached to a boom pole. They will normally pick up all sound coming from the direction in which the mic is pointed. The Sennheiser MKH 8060 shotgun mic is a lightweight yet rugged shotgun mic that can withstand tough climates. It has a super-cardioid pickup pattern and runs $1,250.
Lavalier, or lav mics are used mostly for video interviews or if you have someone talking and don’t want the mic to be seen. You attach them to the talent’s clothing to record the person’s voice very clearly. The RØDE Lavalier mic ($375) has an omni-directional polar pattern and condenser element. It works best for general sound pickups, such as interviews, presentations and instruction. It comes with a handy protective storage case, waterproof pop-filter, wind-muff and clip.
Handheld mics are the most durable of all three and are often used by reporters or during casual interviews. Audio-Technica’s AE6100 ($299) dynamic handheld mic delivers a clean, crisp sound. Its hyper-cardioid pattern provides excellent isolation of the desired sound source.
Balanced and Unbalanced
Most mics on the market today have a balanced output . What is balanced? Balanced means that inside such mic cables there are three wires. One is positive, one is negative and the third is grounded. There are transformers at the ends of the cable that will convert the three into a normal signal. This allows for the use of longer cable runs that are less susceptible to interference. An unbalanced cable simply has an audio signal and a grounded wire. Unbalanced is more susceptible to extraneous noises but if your cable is 10 feet or less in length, you should do fine. The Azden SGM-2X shotgun mic provides a low-noise signal through its balanced XLR output for $320. While the Shure WH20 Dynamic headset mic ($95) is tailored to users that must move around, and it can clip audio before distortion occurs.
Another factor to consider when purchasing a mic is the element. There are three main mic types: condenser, dynamic and pressure zone or PZM. Many mics you’ll consider are condenser. They are very sensitive to sound and tend to be fragile, and so require careful handling. Some condenser mics are for studio use only but their sound reproduction allows you to achieve the best quality sound. Azden’s SMX-20 ($200) is a stereo electret condenser mic that offers a directional high quality stereo sound. It is designed to work with DSLR cameras, but has a shoe that will fit most camcorders as well.
Dynamic mics are less fragile. They do a good job in varying climates and have the ability to pick up a wide range of sounds. They are mostly used outdoors because of their ruggedness. Another Azden mic is the WM/T-PRO VHF Wireless Microphone ($180). It has a transmitter built in and has a rubberized coating for reduced handling noise.
Pressure zone mics, or PZMs, work in a different way. They are made up of a tiny mic element that is placed just a few millimeters above the hard surface of the mic. This type of mic responds well to sound that reflects off the surface. They are great for recording quality sound minus extraneous, ambient noise. The Crown PZM-11LLWR mic ($225) is a weather-resistant pressure zone microphone with a balanced output. It is designed be mounted on a typical electrical outlet. The mounting style and need for power should be enough to keep its uses to very specialized needs such as outdoor intercoms.
Pick Up Pattern
Another feature you need to know about when purchasing a mic is its pickup pattern. The pickup pattern determines the sound pattern and from which direction the mic captures sound.
Omni-directional mics pick up equal amounts of sounds from different directions. A directional mic will pick up sounds from its front. The goal is to isolate the sound you want while keeping out ambient noises. Directional mics come in three more categories, cardioid, super-cardioid and hyper-cardioid, each picking up sound in front of the mic narrower than the next. The shotgun mic is the most directional of all mics with the tightest pickup pattern in front of the mic.
The ME 62 ($160) by Sennheiser is an omni-directional mic that can capture great room tone and ambient noise. The RØDE NTG1 ($349) condenser shotgun mic is lightweight and designed for professional applications in the film, video and TV industries.
The frequency response of a mic is a range between two figures. It is a way to know what frequencies a mic can capture. For example, a mic that has a frequency response of 20Hz to 20kHz can reproduce all frequencies within that range. There are mics that do not alter frequency at all. This flat response meanins it is sensitive to all frequencies equally. Condenser mics in general have a greater range of frequency response than dynamic mics.
Wired or Wireless
A wired mic is physically connected to the recording source, usually your camcorder, by way of a cable. In contrast, a wireless mic does not connect directly to your source. It is consists of three parts: a transmitter, a receiver, and the mic itself, then there may be wires between the mic and the transmitter and between the receiver and your recording device. Deciding which one to use depends on factors that are largely application-specific as well as your own personal preference.
A wired mic does not transmit a signal, therefore it is less likely to pick up extra noises and interference. Because they are more common than wireless mics, they are usually less expensive and easier to use. Wired shotgun mics are one piece of equipment that no video enthusiast should be without. They’re great because they can pick up audio from any direction they are pointed in. They are able to capture very crisp and clear sounds as long as they are close enough to the subject. One drawback to wired mics is that because you are physically connected, the mic has to stay close between talent and camera, thus you are unable to move quickly. The Sennheiser MKH 416 ($1,000) is a compact super-cardioid shotgun mic. It has very good directivity. It’s a good choice for just about any type of application.
On the other hand, wireless mics allow you to receive very good audio quality in a wide shot because the mic is not connected to the camera. However, the disadvantages are that they are susceptible to picking up interference and, because they are generally attached to the talent’s clothing, they may also pick up the rustling of his/her clothes. Audio-Technica’s 1800 Series camera-mounted wireless mics are very versatile and easy-to-use portable wireless mics. They are come in dual-channel and single-channel systems and its True Diversity operation allows for resistance to interference and dropouts. Because there are advantages and disadvantages to both wired and wireless mics, it makes sense to have one of each plugged into separate audio channels on your camera or recorder.
While there are many factors to consider when purchasing a mic, your main concern when deciding which one to get is what applications you will be using the mic for and also how much money you are willing to spend. The market is flooded with a wide variety of solid, top-quality mics, for many different applications, ranging in price from $50 (or less) to $1,200 (and more). The choice is yours, and if you carefully consider all the factors, applications and prices of mics that are out there, you will likely make the right choice. The bottom line is, you can’t go wrong with a good, solid, external mic in addition to the one already included in your camera.
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Teresa Echazabal is a freelance video editor, writer, and producer.