If you're shooting in a place with a lot of electronic equipment, be careful of magnetic interference. Magnetic interference gives you pops, crackles, and static along with hissing or humming sounds. Here are some easy ways to avoid these problems:
- Use a condenser microphone
There are two basic types of microphones: the dynamic microphone, which uses a coil of wire suspended in a magnetic field and a small electric current to generate sound waves; and the condenser microphone, which uses a thinly charged membrane to produce sound waves from a varying signal voltage. Because of their design, dynamic microphones are prone to magnetic interference from electrical mains. Using a condenser microphone will help limit electrical interference. - Don't cross cables
If you're picking up buzzing or humming, make sure your sound cables aren't crossing electrical lines. Wires and coils carrying electric current have magnetic lines of force around them. Unplug appliances when necessary. - Beware of wireless
Wireless (radio) microphones are great for moving around without having a bunch of cables attached, but they can pick up radio stations or local dispatchers, and they get sound drop-out due to electric cables or physical obstructions. If you have problems, use a cable connection.
