CHAPTER 33

LOCATION SOUND

Sound recording is the neglected stepsister in low-budget or film school filmmaking. The most common oversight is to record without monitoring through headphones, trusting that all is well. Machines have nasty little black souls all their own, so all is frequently not well and you later find there are crackles, dropouts, or no sound at all. Thus, the reward for misplaced optimism …

Another costly assumption is that location sound can be skimped because it can be fixed in the cutting room. Though true to a degree, this is damaging when practiced wholesale, for recreating dialogue later in a looping or automatic dialogue replacement session is damaging to your drama and expensive in time and effort. See following sections for explanations.

Any low-budget film's effectiveness depends absolutely on getting good original dialogue tracks. This takes preparation, skill, and the will to accommodate the needs of those responsible for sound recording. In a fine article full of information and examples from a raft of feature films, sound designer Randy Thom contends that most directors have no sound design consciousness at all. Even the professional film industry relegates location sound recording to lowest priority. You can find his article through at www.filmsound.org, an excellent Web site for all sound information.

Following are some basic guidelines for successful sound coverage.

MONITOR ALL RECORDED SOUND

All sound that is recorded must be carefully monitored through high-quality headphones that enclose the ears and isolate the user from external sound. No exceptions, ever.

SOUND THEORY

How sound behaves in different environments is logical enough to anyone who has ever watched kids throwing balls in a small courtyard. Of course, there's a lot more to sound theory than how sound bounces, and you should read up on it. But even a small amount of knowledge will help you choose film sound environments wisely and enable you to understand when your sound recordist explains a problem. Again, www.filmsound.org/ is a good source for all sound information.

The most potent aspects of sound for film lie not just in faithful recording techniques but also in psychoacoustics, which describe the perception of sound by an audience. The doyen in this area is the French sound expert Michel Chion, whose Audio-Vision-Sound on Screen (New York: Columbia University Press, 1994) explains the ideas he has been developing over the last 30 years. Be warned that his ideas are not simple and require learning a specialized vocabulary.

SOUND EXPERTS SHOULD SCOUT EACH LOCATION

During preproduction, when you choose locations, have your sound crew scout the location along with the director of photography (DP) and director. On seeing where you want to shoot, the sound department may argue persuasively for an alternative, and you should take what they tell you seriously.

The first thing a sound specialist does in a new location is to clap her hands, once and loudly. She is listening to what follows the attack of the hand clap. Ideally it is an equally rapid decay. If the room is live (reverberant) there is an appreciable comet's tail of sound being reflected and thrown around the room. This concerns her greatly. The composition of surfaces in a location can make the difference between sound that is usefully dry or non-reverberant, and that which is unworkably live and reverberant. Reverberation is multiplication of the original or source sound by hard, sound-reflective surfaces. A resonant room is one that has a “note” within the range of speech to which the room resonates. You'll know this phenomenon from singing in your shower, and finding one note (or frequency) at which the room joins in, augmenting your song with a resonance of its own. Resonances are bad news to sound recordists.

If the room is small, they may recommend that you mock up the desired small space within a larger one, to avoid a boxy acoustical quality. How do you know how bad this will be in advance? The best proof is to audition dubious sound locations by shooting tests. Record some sample dialogue from representative microphone positions, then edit the results together. In no time at all, you have the measure of your problem. The sound crew will be concerned with:

• Reflectivity of ceiling, walls, and floor (drapes and carpet greatly reduce this)
• Whether there are, or can be, soft furniture or irregular walls to break up the unwanted movement of sound within the space
• Alignment of surfaces likely to cause standing waves (sound bouncing to and fro between opposing surfaces, augmenting and cross-modulating the source sound)
• Whether the room has intrusive resonances (this happens mainly in rooms with a lot of concrete or tile surfaces)
• Whether actors can walk and cameras can be dollied without the floorboards letting out tortured squeaks
• Ambient sound and sound penetrating from the outside

Typical intermittent sound intrusions from the surroundings occur when you are:

• In an airport flight path.
• Near an expressway, railroad, or subway.
• Near refrigeration, air conditioning, or other sound-generating equipment that runs intermittently and will cause problems unless you can turn it off while shooting.
• Near construction sites. You scouted the location on a weekend, not realizing that come Monday morning, a pile driver and four jackhammers greet the dawn. You have no hope of stopping them.

Dialogue shooting must usually be done with all doors and windows closed. In summer this can be trying, but part of checking a location is to ensure that you can get electric power cables in under the doors so they can be completely closed during takes.

UNWANTED LOCATION AMBIENCE

Locations come with all sorts of problems, with wind and other ambient noise at exterior locations being prominent. Beautiful autumn leaves may introduce the sound of swishing cornflakes as actors walk and talk. Sound from an expressway may be minimal at 2 in the afternoon and rise to a dull roar by 5 o'clock when the rush hour begins. Overhead wires turn into aeolian harps, dogs bark maniacally, garbage trucks mysteriously convene for bottle crushing competitions, and somebody starts practicing scales on the trumpet. Some of these sonic disasters the astute location spotter can anticipate, some not. During the scout you look for clues to Armageddon, then take your chances.

Urban locations spring most of the cruel surprises on the sound recordist, yet it's usually sound that makes a film work dramatically. There is no substitute for experience and a good complement of sound gear to create optional ways of covering the situation.

SOUND EQUIPMENT

As with all equipment, never leave the checkout point without putting all of it together and testing that absolutely everything functions as it should. Make sure you have spare batteries for everything that depends on a battery and extra cables, which have a habit of breaking down where the cable enters the plug body. Carry basic repair equipment, too: screwdrivers, socket sets, pliers, wire, solder and soldering iron, and a test meter for continuity and other testing.

RECORDERS

For highest reliability and highest quality recording in either analog or digital format, the Nagra range of recorders is unparalleled. A digital audio tape (DAT) recorder such as those made by Tascam are often used on lower-budget productions. Some DATs offer up to eight tracks on one machine, which means you can record up to eight monophonic microphones, or four stereo, and worry about mixing a useable master track later. A recent trend is to record into a portable hard drive. The Zaxcom Deva II is a four-channel location mixer and recorder that can pack 60 track hours of uncompressed recording into a tough and hermetically sealed hard disk. It has a 10-second sound buffer that can reclaim the 10 seconds of sound prior to switching on—very useful for spontaneous shooting or the odd missed cue, for you know the previous 10 seconds are included with the recording. The hard drives can be rapidly downloaded in the cutting room or even plugged directly into the computer, and having no moving parts, the machine is immune from grit and dust, as well as temperature and humidity extremes (see www.zaxcom.com). The conservative sound engineer may want to simultaneously record on tape, too, “just in case.”

MICROPHONES

Film recording is done with a variety of microphones made by Sennheiser, Schoeps, Audio Technica, and other manufacturers. While an omnidirectional mike produces the most natural voice recording, it can seldom be used because it picks up sound from off axis, such as reverberant or ambient sound. Contrary to legend, there is no such thing as a zoom microphone and no way to cheat a microphone's characteristics to make it sound close when it is distant. A close recording can, however, be made to sound distant in postproduction by adjusting its level and subtracting some of the lower frequencies, which fall off earlier over a distance than upper frequencies.

The counterpart to an omnidirectional mike is a cardioid or directional mike, which gets its name from its heart-shaped pick-up pattern. Cardioids are able to discriminate against sound coming from the sides or behind, and by suppressing sound from unwanted directions, their signal-to-noise ratio is enhanced. This means ambient and reflected sound are a little lower in relation to the desired source. The hypercardioid or gun mike (because of its shape and appearance) does the best job of discrimination, but at some cost to naturalness of reproduction. Other mikes have various advantages and disadvantages, but basically there is no substitute for a quiet background and a good mike close to each speaker.

Another answer to miking actors is the lavalier or body mike connected to a personal radio transmitter. Radio mikes are worn on the body and produce a good and constant voice level with a low ratio of ambient sound. They do, however, have one or two little quirks. Unless you obtain top-rate, wireless systems, radio transmission sometimes fails or unexpectedly pulls in taxis and police messages. They are also prone to picking up clothing rustles and body movements, especially if an actor is wearing any clothing made from man-made fibers. These generate static electricity, which is thunder on a small scale.

Lavaliers are without sound perspective. This is the aural sensation of distance we get from acoustical changes in a voice as someone moves around. Partly it's due to changes of subject-to-mike distance and partly the voice's changing relationship to its acoustical surroundings. The lavalier, by remaining at a constant distance from the speaker and picking up so little reverberant coloration, removes all sense of the speaker's movement or perspective changes. These must be emulated later in the mix. Live now, pay later.

BOOM

An overhead microphone boom is a large and specialized piece of mike support equipment that needs plenty of space to operate. Low-budget productions generally use a hand boom or fishpole, which has the added advantage of being able to place the mike out of sight below the frame instead of above it.

MIXING DESK

Most location recorders are two-track stereo and need a battery-powered mixing desk when several mike inputs must be combined and balanced. Mackie makes ones favored by low-budget productions. Monitor all sound using professional, ear-enclosing headphones that isolate you from the surrounding world.

RECORDING REQUIREMENTS

DIRECT AND REFLECTED SOUND

In dialogue sequences, the sound crew aim to get clean sound that is on mike, which means spoken near a microphone and into its most receptive axis. They want sound that is relatively uncolored by sound reflected from walls, ceiling, floor, or other hard surfaces like tables and other furniture. Reflected sound, bouncing off surrounding surfaces before finding its way to the mike, travels by a longer route and arrives fractionally after its direct, source sound. If loud, it can appreciably muddy the clarity of the original. You may not realize this until you start editing different mike positions together—position changes mandated by the different camera positions necessary to any well-covered dialogue sequence. In a reverberant location, each mike position has a different sound characteristic determined by the different admixtures of reflected sound and the different distances from the speakers. Editing them together makes all the seams evident in what should sound seamless.

Reflected sound can be greatly reduced by laying felt or other soft, sound-absorbent material on hard floors and hanging blankets in front of any walls out of camera sight. To be fully effective, blankets must be hung about 6 inches away from the wall, not directly on it.

Getting mikes close enough to actors without causing shadows will require planning between sound and camera specialists and the director. Quite often this requires placing more than one mike and feeding their inputs into a mixer. Location sound must be thought out carefully because every mike left open records its own share of ambient, source, and reflected sound, and these joined together can produce a chaotic set of problems. If you can, record each mike into a different sound channel (by using something like an an eight-channel DAT recorder) and keep their contributions discrete. You can audition the various mike outputs later and make a mix of the most successful coverage. If mixing must be done on the spot, the sound mixer really must know what he or she is doing, for once mixed, the omelette cannot be unscrambled. After the first mixed take, listen to the results through the headphones before proceeding.

SOUND SOURCE TO MICROPHONE DISTANCES

Getting microphones close enough to actors on the move so you can record well is a rare skill. The boom operator's main task is to stay just out of frame at all times, but also near the axis of each speaker. Not doing so means that sound levels plummet as the mike-to-subject distance increases. Ambient sound levels, however, remain constant. Thus the ratio of source to ambient sound can vary a lot. Cranking up the playback level afterward in the mix can compensate for the drop in source level and make the speaker's voice consistent from angle to angle, but at the expense of large changes in the ambient levels that were recorded with each angle.

The fundamental problem is that film-shooting procedures are usually optimized for photography. Sound recording must fit around the needs of the camera and at the same time keep its microphones from ever being visible. The director can help by stabilizing speakers during a dialogue sequence, minimizing sound recording problems, or creative set dressing so a nice potted plant on a dining room table conceals a strategically placed microphone.

AMBIENT SOUND AND PRESENCE TRACKS

Ambient sound is sound inherent to the location, whether interior or exterior. A playground may have a distant traffic accompaniment coming from one particular direction. A riverside location may have the hum of a power station a quarter mile off. Every room you record in will have its own ambient sound noticeable only during silences. It may be a faint buzz from fluorescent fixtures, the hum of voices from an adjacent office, or birdsong and trees rustling from outside.

Before calling for a wrap at any location, interior or exterior, the sound department always records an atmosphere track (also known as room tone, presence track, or buzz track). The procedure is simple: on the heels of the last scene, nobody leaves the set or changes anything and actors and crew freeze. For a couple of minutes the sound crew makes a recording of the particular quality of silence in the location. This becomes the all-important sound filler for gaps in dialogue tracks. The two minutes can be duplicated to create as much track as needed.

SOUNDS ON THE SET

It's imperative to keep the crew stationary and silent during takes and to make sure that the camera isn't making any sound the mike can pick up. Most film-camera sound comes from the hollow metal magazines, and these can be muffled with a soft, sound-proof casing called a barney. When this fails, sound may pass through tripod legs and be amplified by a resonant floor. Placing carpet under the camera support should fix this. Fluorescents like to buzz, filament lamps can hum, and pets come to life at inopportune moments. Sound cables, placed in parallel with power cables, may produce electrical interference through induction, and sometimes, long mike cables pull in cheery DJs via radio frequency (RF) interference. Any large motor or elevator equipment can generate alternating current magnetic fields, and the most mysterious hum sometimes proves to come from something on the floor above or below.

SMART SLATE

A smart slate is a type of clapper board containing a timecode display that comes on when the bar is opened and whose timecode freezes at the point where the clapper bar is closed. This makes synching sound to its timecoded picture easy. However, camera and recorder must be compatible with the smart slate, and the camera department must jam-synch (synchronize) the timecode generators every morning because they drift apart over a period of time.

EFFECTS AND WILD TRACKS

A wild track is any track shot independent of picture. When an actor flubs a line or some extraneous sound cuts across a line of dialogue, the alert sound recordist asks for a wild voice-only recording immediately after the director calls “Cut.” This way the actor repeats the lost line just as he or she spoke it during the take. By recording in exactly the same acoustic situation, the words can usually be seamlessly edited in, and a reshoot avoided.

An effects track (FX) or atmosphere is a wild recording of sounds that might be useful to augment the sequence's sound track later. The recordist might get a separate track of that barking dog, as well as other sounds to help create a sound-scape. In a woodland location this might mean getting up early to catch bird calls, river sounds of water gurgling, ducks dabbling, and wind rustling in reeds. A woodpecker echoing evocatively through the trees is probably best found in a wildlife library, as they are hard to get close to. Initiative and imagination are important in the sound recordist, plus a high level of tolerance to frustration.

AUTOMATIC DIALOGUE REPLACEMENT

Automatic dialogue replacement (ADR) in postproduction, sometimes called looping, is expensive and time-consuming and mostly kills all dramatic potential. The problem is that actors can never regain the emotional truth of a scene when they record one line at a time in a sound studio. Actors loathe doing it. ADR is misnamed: It is neither automatic nor any real replacement.

ATMOSPHERE LOOPS

Often a short original atmosphere is made long by repeating or looping it. This can be perfectly acceptable unless recognizably individual sounds return at set intervals. A bus station with the same sneeze or cackling laugh every 6 seconds makes for a very strange place indeed. When recording atmospheres, the recordist listens intently to make sure an appreciable amount, clear of such noises, has been recorded so an effective loop can be made later. By the way, atmospheres in sound libraries are often loops, and they often have giveaway sounds.

SOUNDSCAPES

While researching for this chapter I discovered that a World Soundscape Project researching the acoustic ecology of six European villages began in 1975. Sponsored by the Tampere Polytechnic Institute in Finland, the goal is to document acoustic environments in change over time (see www.6villages.tpu.fi/). The Web site gives an idea of the riches you discover when you set out to explore using your ears, something I learned as a teenager from Brian Neal, a musician and great friend who is blind. Every place has its soundscape, and what makes it individual and special takes listening and analysis. To create with sound is to provoke imagination at a high level, much as music does. Usually the most memorable soundscapes come from simplifying and heightening rather than being literally true to everything in the location. Less is more in sound as in everything else.