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Article: Getting Great Audio in the Field

By Jeffrey P. Fisher

Remember

  • Audiences put up with "bad" video, but NEVER poor sound.
  • Dialog rules! Focus on capturing top-quality voice in the field. Most other sounds can be added in post-production.
  • Always capture room tone and/or presence at EVERY location. Room tone/presence smoothes and hides edits, making the finished track sound better.

Microphones

  • Use external microphones. The built-in camera microphone is good for one thing: picking up the noise of the camera. Keep all mics away from noisy gear, too.
  • Microphones do not discriminate like our ears do; they hear everything. Choose directional mics for a more focused sound. Directional mics reject off-axis sounds (usually noise you don't want).
  • Rely on one mic when you can as multiple mics close to one another can create phasing and other nasty results when summed in post.
  • Dynamic mics are good for locations (especially in bad weather), as they tend to be more rugged. If you use condensers, always have extra, FRESH batteries and/or a backup power supply.
  • Wind woes. Foam windscreens are only marginally effective. Furry zeppelins are better. Omni-directional mics are less susceptible to wind noise than cardioids. Point omnis away from source of wind.
  • Keep cable runs as short as possible.
  • Secret microphone technique? Point the mic at the source and get closer.

Fisher's hierarchy of microphone choices

  • Lavaliere clipped to talent (or hidden). Try an Audio-Technica AT-831
  • Planted microphone (handheld, PZM, lavaliere). Try Shure VP64AL omni, SM57/58 cardioids, Shure PZMs, or AT-831 lav
  • Shotgun (or other uni-directional mic) on a fishpole boom. Try Audio Technica AT-835ST or a Sennheiser 416.
  • Wireless (usually a lavaliere). Try the Audio-Technica ATW-U101 system

Mic details

  • Use audio channels wisely. Route lav to L; shotgun to R. Wireless lav to L, planted mic to 2. One mic routed to both channels with one channels level set 10 dB lower (to cover volume changes).
  • Lavs are great for interviews. Some people don't like the sterile, in-your-face sound of lavs. Place them farther away for a more open sound; closer for tighter, more intimate results.
  • Avoid unusual and distracting placement. Hide them if you prefer not to see them on camera.
  • Hidden lavs are susceptible to clothing noise. Tape the mic securely to the clothing to minimize rustling.
  • If the talent stands or moves while wearing a wired lavaliere, consider taping the belt-pack power supply to the leg, just above the ankle. This way the cable comes out the pant leg with fewer tangles, trips or restrictions.
  • Planted microphones work well if there is minimal talent movement (though you could use multiple mics on the set).
  • Get creative when planting mics. Clip lavs to nearby furniture. Use a PZM on a desk (cover it with one sheet of paper to hide it). Hide mics behind books, furniture, other people, and, of course, in ... uh ... plants!
  • Shotgun on a boom is often a better choice than planted mics, but require an assistant (which you may not have). Boom work is great for dramatic scenes and/or when there is both camera and talent movement. Booming from above is often a more open, crisp sound. Boom from below can sound "heavier".
  • Shotguns are tightly focused. Aim carefully as anything off-axis sounds bad.
  • Use wireless mics as a last resort. Unwanted interference can ruin critical sessions.

Backups

  • As a backup for critical shoots, use an extra wired lav hooked up to a Mini-disc recorder. You could always post-sync this wild track in post. If using wireless mics, always use a MD back-up.
  • Also, have extra mics, cables, batteries, tape, etc. on every shoot.

Post fixes

  • Noise reduction tools in post can help clean up location recordings, too.
  • Sometimes you have to make the track sound worse to sound better. For example, adding noise (room tone/presence) to smooth edits.
  • EQ and compression can make the dialog tracks shine:
  • 100 Hz low-shelf and 10,000 Hz high-shelf
  • 1-3 dB bump at 160 Hz for male or 320 Hz) for females for warmth
  • Mid-range dip 2-4 dB between 500-800Hz to minimize mud
  • A little sparkle, 1-3 dB, in the 7-8kHz area (listen for sibilance though)
  • Gentle compression (post-EQ). Try 3:1 compression starting at -15dB







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