Sound Track: To Wire or Not to Wire?

It doesn't take a lot of experience to realize how important good clean audio is. And how you acquire that audio is going to have a direct impact on your finished video. Since most cameras have an internal microphone, many novice video producers assume that they don't need an external mike. However, many problems can crop up if you use the built-in camcorder mike as your sole audio source. Often it is too far away from your subject to get good sound. It can also pick up camera noise, such as the sound of your zoom motor. More often than not, an external mike is essential to get good audio.
There are many different types of microphones, more than we want to get into this month. (For a good review of the various mike types see Mike Types in the August 2000 Sound Track column.) What we are going to focus on in this article are the fundamental differences between wired and wireless mikes. Whether you're planning to use a stick mike, a boom or a lavalier, you still have to decide if you want to use a wireless mike or a wired mike.
A wired mike, sometimes called a hardwire, is a microphone that is physically connected to the recording source, in most cases your camcorder. A wire runs from the microphone to the recorder, thus the name wired. A wireless mike doesn't have this direct wire connection. Wireless mikes have two parts, a transmitter and a receiver, in addition to the microphone itself. The transmitter converts the sound from the microphone to a specific radio frequency and broadcasts it to the receiving unit near your recorder. The receiver converts the radio frequency back to a standard wire signal and into your recorder.
Knowing which type of mike to use, and when to use it, is not always an easy task. Many factors go into deciding whether to use a wired or a wireless mike. The best way to approach the problem is to understand the pros and cons of both types and choose accordingly.

Wired Mikes

There are many good reasons to use a standard wired mike. They are more common than wireless mikes, generally less expensive and are often simpler to use. Depending on the specific type of microphone, you may not need any batteries to drive the signal at all. This is good because any time you rely on a battery, there is the chance that the battery could fail while you're recording.
Wired mikes connect directly to your camcorder. They don't transmit the signal, so they have a tendency to get little or no interference, giving you more reliability. When you do have a problem with the signal, it can often be easy to check with a wired mike. The signal path is completely visible, just follow the wire from the camera to the mike. You can usually see where the problem is, such as a loose connection or a frayed section of your cable.
Unfortunately, those same positives, can also be negatives. The fundamental nature of a wired mike, connecting directly to the camera, can be a bad thing. When using a wired mike, your video camera is physically connected to whoever is holding or wearing the microphone. It�s not enough for you to know that, your subject needs to be aware of it too. Imagine interviewing someone with a wired lavalier mike. When the interview is over, the interviewee gets up and starts to walk away with the mike still connected. There goes your camcorder, too.
That same wire that gives you more reliability and security can also be a hazard. Someone could very easily trip over it and pull your camera off its tripod. A wired mike can also cause problems with the composition of your shot. The length of the wire limits where you can put your talent, and the wire itself can sometimes be difficult to hide.<…