Production Sound

The following article is a overview written by Fred Ginsburg C.A.S., Ph.D. It is somewhat dated now (talks about Nagra and DATs) but contains priceless information throughout.

What is Production Sound?

It is the complex craft of recording live dialog and sound effects on the set during principal photography (production). It requires a blend of creative judgment, technical expertise, and acceptable compromise! It is also the art of creative problem solving. You often need to remind directors that sound is important, too. Eyes see, but ears imagine.

In This Section:

  1. Pre-production
  2. One-Person Sound Crew
  3. Two-Person Sound Crew
  4. Basic Equipment Packages
  5. Headphone Monitoring
  6. Recording the Signal
  7. Priorities
  8. Microphone Pickup Patterns
  9. Other Information

Pre-production

Scout locations with eyes closed and ears open. Cameras can frame out distracting views, but noise is all around. Scout on the same day of week and time of day as your upcoming shoot.

Hire a professional crew and the best equipment possible. A few extra dollars spent up front can save thousands in post.

Solve problems BEFORE they become problems. Improve the recording environment; cheat action. Attack the offending noise whenever you can! Sound blankets, foam sheets, booties, throw rugs.

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One-person Sound Crew

A one-person crew is very limited in capability. Types of sound from one person is limited to:

  • Non-distinct background ambiance
  • Talking head with lavalier (close-up perspective on immobile interviewees)

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Two-person Sound Crew

A two-person crew is more versatile and professional. More can be done, including theatrical quality soundtracks. A mixer can mix sound from the near camera; the boom can move to a strategic position closer to talent. The two-person approach is necessary for dramatic sequences or complex staging.

Sound from an aimed overhead mic is higher quality and more natural than from lavaliers. When on lavaliers, sound from the boom records footsteps, doors, objects, props, etc. to add texture to track. This saves on post- production, especially for low-budget films.

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Basic Equipment Packages

As previously stated, always use the best available. Prepare for all contingencies; bring EVERYTHING! Pack back-up gear.

Setting levels: V.U. meters are averaging. Peak meters are peak reading. In film, set 0 VU on mixer to -8 db on Nagra. In DAT, set 0VU on mixer to approx -18 to -22 on the DAT.

In video, record bars and tone at 0 VU on VTR. Then readjust VTR input so that 0 VU (mixer) corresponds to -3 VU (VTR). This allows for extra headroom on dialog.

Use line level outputs from mixer to recorder for less interference. If line level signal must be reduced for use with mic level input, use 50 dB-worth of pads/attenuators.

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Headphone Monitoring

Monitor from the recorder when possible, so there are no surprises.

Direct vs. tape/peck. Confidence head is off of tape, but has a slight delay. Direct is better.

Be attentive to buzz, AC hum, SMPTE bleed, ground loops, RF, and radio/ TV. Impedance of headphones should be approx. 50 ohm. Adapters for stereo/mono, should be 1/4 inch to mini.

Use of ear wigs, open ear versus closed ear: Sony MDR-7506 are industry norm. Adjust level so that 0 VU is like loud telephone.

Duplex boom cables: The boom should always hear the entire track, not just the boom mic, in case of multiple mic phasing problems.

Safety considerations for mixer and boom: Protect your hearing! The mixer can monitor off of tape for protection. Warn boom operator and any others listening. Keeps pots closed except when mixing. Protect the ‘privacy’ of talent on lavs and radio mics.

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Recording the Signal

Equalization should be minimal, except to roll off unwanted low end (wind noise, rumble); use a slight mid-range boost to enhance dialog. Only do active EQ when there is no alternative; once it is done, it cannot be undone, and it is better to leave it for post. Match your plant mics to the primary mic. Be cognizant of continuity.

Always allow 5 to 10 seconds for ‘speed’ after transport has stabilized. This provides ‘pre-roll’ for post-production lock-up time. Talk through the ‘waiting period’ between ‘roll’ and ‘speed.’

Multiple mics: Think one mic at a time. Keep other faders ducked down to avoid phasing problems.

Be aware of background ambiance level: think consistency! Establish relative levels for talent, and maintain consistency even on close-ups. Voice quality is different than volume.

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Priorities

As mentioned before, Production Sound is an art of compromise on the set. Dialog is recorded with picture, and both must give way a little bit. The job of the Production Mixer is to record raw material for the editors and re- recording mixers to transform into a finished soundtrack.

  1. One – Therefore, the first priority is to get the dialog any way possible so that it is usable. In the event that laying down usable dialog is impossible, you should still try to get as near perfect a track anyway, even if it is only to be used as a guide track for ADR (looping).
  2. Two – Your second priority is to record the dialog in matching perspective for the camera angle.
  3. Three – Your final priority is to record sound effects to accompany the shot. This might include such things as footsteps, hand props, doors, etc. Sometimes this is recorded during the actual take, during a rehearsal, or after the shot. Some productions may also ask for presence (room tone).
Hint: If you are requested to record presence (room tone)., arrange to do it just before the camera roll of the first take. That way, everyone is in position and the sound will be an exact match of the actual take. Waiting until the end of the last take results in having to fight the commotion of exiting talent, crew, and wrapped equipment.

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Microphone Pick-Up Patterns

Microphone Type
Pick Up Pattern
Omni all directions
Cardioid heart shaped, slightly directional
Supercardioid or Hypercardioid rather directional. Beware of tail. ‘Short shotgun.’
Ultra-directional As the name implies, very directional. Beware of tail. Long ‘shotgun,’ parabolics
Bi-directional figure eight
X-Y Stereo discrete left and right pickups
M-S Stereo (mid + side), (mid – side) are matrixed to create left and tight channels. Stereo spread can be controlled in post, but matrixing requires special decoders and may cause complications

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Other Information

The recorder is usually a Nagra (either a 4.2 mono, IV-S two-track, or Nagra III), DAT (portable timecode usually), or a VTR. Always try to monitor out of the record deck rather than the mixer, in case of RF interference or ground loops.

The mixer is of paramount importance. On a set, it is not so often a question of mixing a large number of inputs as it is being able to exert control over one or two. A good mixer should offer four to eight inputs (rarely will you ever need more than that), limited equalization, lots of input gain, and a communications module.

EQ is hardly used, except for bass roll-off and a slight mid-range boost to help punch the dialog. Plant mics and lavaliers are equalized to sound like the main boom mics.

Anything more than that is best achieved during post-production. Signal processing does not belong on the set; it should be done later on during final re-recording. Films are shot out of sequence, with shots being torn apart and edited together to create finished scenes. Attempts to prematurely process the track can cause a myriad of matching problems.

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