In the previous article, we stressed the need for proper monitoring of your audio and careful selection of your headphones. This month, we will look at the importance of proper microphone placement.
As musicians, you’ve had it relatively easy when it came to deploying your mics. Vocal microphones are kept close to the singer, often just inches away from the face. Instrument microphones are also at point blank range. These extremely close proximities are routinely practiced, even though the vocalist may be near screaming, and the volume of most raw instruments (or their amps) far exceeds that of the human voice.
(I know… Pure tracks, avoiding feedback, preventing audio bleed, and that sort of thing.) The point that I am making is that even with such high volume sources, audio engineers rely upon close-up miking to keep it all clean.
Yet when it comes to recording audio for video, it seems like the lessons learned in the recording studio are all but forgotten! The most common equipment set-up is a medium grade, electret condenser, short shotgun mic mounted directly atop the camcorder.
There are two major problems with that:
To begin with, you are probably recording ordinary level conversation or interview, not loud instrumentals or screaming soloists. Their sentences aren’t going to carry very far, and especially not if there is any background noise. You need microphones that are very directional and generally more sensitive than what you would need for music.
The second issue is that although light (as in picture) can travel seemingly without loss over great distances, sound waves dissipate quickly. Just because a common telephoto lens can zoom in on it and see it, does not mean that our microphone can isolate it and hear it.
Assuming that you are just shooting a simple interview in a moderately quiet room, it is unlikely that you would shove your lens only a foot or two away from the subject. Realistically, your camera would be seven to 10 feet away in order to frame a comfortable medium shot or close-up.
That is where the problem lies. A shotgun mic, mounted on your camera, would also be seven to 10 feet away! However, at that distance, your audio will be thin and heavily tainted by room noise and any background elements.