Location Sound Basics
This overview summarizes the most important points about on "location sound recording" or "field recording", split into pre-production, production and postproduction.
1. Introduction
Central questions
How do I design the soundtrack of a short video, which on the one hand shows a "real" application situation, on the other hand clarifies a concept?
Which audiovisual styles do I orientate myself on (feature film / documentary / reality TV / advertising...)?
How can I use sound to support the narrative?
How can I use the sound to have more possibilities on the visual side (and vice versa)?
Also read: Randy Thom, Designing a Movie for Sound http://filmsound.org/articles/designing_for_sound.htm
Some functions of audiovisual narration:
Creating credibility and realism through sound
Rhythmization / vectorization of the image
Diegese: Is a sound part of the depicted world?
Narrative perspective, camera perspective, sound perspective
Sound semiotics: sounds and music as signs (e.g. ticking = time), "potentials of meaning".
Sound semantics: material / movement / space, setting, scenography / symbols / keysounds ...
2. Pre-production
2.1. Audiovisual storyboarding, spotting
Scripting
Storyboarding (audiovisual)
Spotting sounds: determine sounds for individual settings according to script / storyboard
2.2. Planning the recordings
Location: Access, Soundscape
Foley: Suitable room (quiet, "dry"...)
Effects / Sound Design Raw Material
Set Dialog
Voice Overs / Dialogue Replacement
2.3 Microphone: technology and application
Rule Nr. 1: What you hear is NOT what you get!
Microphone is not a camera lens
Microphone types (dynamic, condenser, ...)
Professional connectors: XLR. Advantages: Grounding, shielding, stability. If available, always prefer!
Polar patterns: omnidirectional, cardioid, hypercardioid, shotgun, pressure zone mic.
Examples: Sennheiser me64 & me67
Stereovariants: A-B, Eight, XY
Example: Rode NT 4
Mono (dialog, effects..)
Stereo (Atmos, certain dialog settings with static / perspective miking)
Sound change through distance & alignment.
Phantom power 48v with condenser microphones: via circuit or batteries.
Choosing a microphone for dialogues
(priority: sound quality, naturalness, effort, reliability):
Hypercardioid or shotgun with boom, over head
Hypercardioid or shotgun with boom, under head
Cardioid, hypercardioid, boundary zone or shotgun combined (depending on ambient noise and proximity)
Lavalier in a set (wired)
Lavalier on the protagonist (wired)
Wireless lavalier
Combine multiple microphones to be able to correct mistakes in post-production.
In addition to the recording microphone, it is worth recording a more distant microphone or a room microphone (stereoatmo).
Lavaliers are the first choice for certain settings (e.g. conversation recording, discrete environment).
Booming
Preserve the natural power of a performance
Useful for SFX recording ("ride along", or remote sources)
Needs an "operator".
Use Shockmount (damped microphone mount / "spider")
Mic selection: Narrower polar pattern = more sensitive for motion tracking
Boom orientation: ideal from the top front towards the mouth. At most two close persons can be recorded in this way
Lavaliers (von Louise de La Vallière)
Beneficial when recording conversations. Disadvantage: sometimes they have to be hidden, and they don't sound as good as a good boom mic. If a lav is mounted incorrectly, clothing noises can completely destroy the recording. The closer the less "natural" spatial sound characteristic -> can be counteracted by simultaneous recording with room microphone.
Polar pattern usually omni, alignment not so important.
Consider head movements: The more freedom needed, the further away from the mouth. Sometimes two lavs are mounted
Ensure cable relief (e.g. by attaching the cable to the clothes)!
Adhesive tape / gaffer tape helps to mount the lav so that it does not rub against clothes (Attention: glue residues!).
Lavs as static mic also makes sense, but only if source is close enough.
3. Production: on Location
Rule Nr. 2: Trash In, Trash Out (and 2b: You Can't Fix it in Post)
3.1. Recording
One minute of silence! Atmotrack, room-tone
Always monitoring with headphones! Whenever possible, a separate person should monitor the recording!
Do not use "in camera" mic! (unless it is intentional aesthetics, or a sync guide track is needed)
Video standard: WAV, 48Khz / 24 Bit -> minimum quality
Single or double system: Normally the camera-internal recorder is sufficient if the microphone is used correctly. If an additionally external recorder is used ("double system") -> SLATE & shotlist & logging.
An external recorder can also beused as a backup track or for the ambient mix, or if several sound tracks are necessary.
Sound check before the recording!
Adjust level: Only if absolutely necessary, never during a sound event
Only use automatic gain regulation / limiting in an emergency
Room & Ambient Sounds
Carefully listen for reflections and noises. Optimise mic position accordingly
In closed rooms rather cardioids, outdoors rather shotguns, with additional Atmo Track
Always record "a bit too much" material (-> "handles", flexibility in cutting)