Specifications

HOW TO HANDLE SOME

COMMON MIKING SITUATIONS

ollowing are some hints on choosing the right mics for some common

audio/video applications. In most situations, there is no single “right way” to

do it, but some ways may be better than others. In some cases, you may decide

to sacrifice some sound quality in order to gain some other, more important

benefit, such as accommodating your subject’s refusal to wear a lavalier mic.

There are some general ground rules that always apply, however:

1. Always place the microphone as close as is practical to the sound

source. Every time the source-to-mic distance increases by a factor

of two, the sound pressure level (SPL) reaching the mic decreases

by a factor of four, making clear sound pickup progressively more

difficult. This is called the inverse-square rule, and it applies

whether the distance increases from 6 inches to 12 inches or from

6 feet to 12 feet. This means that the talker-to-mic distance must be

cut in half to cause a significant improvement in sound quality.

2. Use the lowest number of microphones necessary for the situation.

People sometimes have a tendency to “over-mike” a shot, using

three or four microphones when one or two would be sufficient.

Excess mics mean more background noise pickup, greater chance

of feedback or “tin can” sound (both of which we’ll discuss in the

Troubleshooting section), and more levels for the operator to keep

track of. If additional mics don’t make things sound better, then they

will probably make things sound worse.

Situation #1 — The Standup Shot: In this situation, a company officer or

other speaker is either standing or sitting, speaking directly to the camera. If

this takes place in a studio or quiet office, the best mic to use would be a

lavalier, since the speaker’s hands would be free to gesture and we would

eliminate the possibility of a handheld mic being positioned incorrectly or,

worse yet, moved around. The unobtrusiveness of a lavalier mic also tends

to put the talker more at ease, resulting in a more natural look and sound.

If the shot takes place outdoors or in a noisy factory, you will need a

unidirectional mic to cut down the background noise. You could: 1) use a

unidirectional lavalier mic, 2) have the speaker hold a handheld uni-

directional mic (or put one on a stand in front of him), or 3) use a shotgun

mic on a boom, positioned so that it does not appear in the video frame.

This method also permits the talker to move around without getting tangled

in a microphone cable.