186 The Digital Filmmaking Handbook, 4E

Figure 8.10

The Azden FMX-42 is a portable four-channel field mixer.

Headphones

Headphones are the audio equivalent of a field monitor—you need them to hear (or “monitor”) the audio as it’s being recorded. Headphones serve a dual purpose: they block out ambient noise from the set and allow the sound recordist to monitor the audio directly. Because the sound recordist is listening to what is being recorded, as opposed to what the human ear would hear on the set, he will often notice extra noises such as crackling mics and distracting background sounds. Even though you can use small “walkman” type headphones, it’s best to use big, professional padded ones that block out as much ambient noise as possible.

Connecting It All Up

Unfortunately, connecting your mics to your camera, mixer, or deck involves a little more than just matching connectors. Although you might have the right-shaped plug on your microphone, it might not be wired properly for the jack on your deck or mixer.

There are two different types of inputs on a recording device: line-level inputs and mic-level inputs. Mic-level inputs are designed to receive weak, quieter audio signals. A preamplifier inside the mic input boosts the incoming signal to increase its level. Line-level inputs are designed for more powerful signals. Most newer video cameras and mixers or recorders provide both mic and line. Note that you can’t tell the level of an input by its connector—RCA, TRS, or 1/4" phono connectors can all be either mic or line level (see Figure 8.11). However, most jacks are clearly labeled mic or line, and some can be changed from one to the other by flipping a switch, usually located near the jack.

There are two types of microphone connectors: balanced and unbalanced. You can generally tell whether a mic is balanced by looking at the type of plug it uses. RCA, 1/4" phono, and TRS plugs are all unbalanced connectors, while three-prong XLR plugs are usually balanced. One is not better than the other as far as audio quality goes, but if you want to use cables longer than about 25 feet, you’ll need balanced connectors (see Figure 8.12).

If you’re using a consumer grade camcorder, most likely, it has an unbalanced connector, usually a TRS jack. If you’re using a mic with a balanced connector (usually a mic with an XLR plug), then you’ll need to get a special adapter that not only provides an XLR jack, but also alters the mic’s signal. A mixer, like the one in Figure 8.10 will also do the trick.

Chapter 8 n Production Sound

187

Figure 8.11

TRS, XLR, 1/4" phono, and

RCA plugs.

Figure 8.12

Camcorders aimed at digital filmmakers, like the Sony F3, offer built-in balanced XLR audio inputs.

Wireless Mics

Wireless mics are usually lavalier (lav) mics attached to a transmitter (see Figure 8.13) that send the audio signal wirelessly to a recording device, thanks to a special receiver attachment.