The Basic Necessities: A Sound Guide for Production and Postproduction


Developmental Editing, Copy Editing, and Posting by Alexandra Hidalgo

The following article is a sound guide for beginning filmmakers, as well as scholars and film lovers who are interested in better understanding the intricacies of film sound.  Whether you plan on making a short film, a web series, or a feature-length film, there are certain things that you need to know, and do, before you start shooting.  These things can prevent many headaches later on and allow your project to move along much more smoothly.

NOTE: I have added a glossary of terms at the end of this article.  If you find a term confusing, please refer to the glossary for a definition.

1. “Picture comes first!”

I’ve heard those three words in some form or another multiple times during my film career.  And for the most part, the words are correct, with one massive exception: The ultra low budget shoot.  In a big-budget shoot, the picture really does need to come first, because there is nothing that can be done in postproduction about a bad shot, besides reshooting, which no one wants to do.  Sound problems can often be fixed in postproduction with the right software, hardware and knowledge.  Didn’t get a clean line?  You can ADR (automated dialogue replacement, which is the act of rerecording or “dubbing” over lines for better clarity in postproduction).  Sound generally a bit noisy? Clean it up with sound editing software.  There is also foley (recording or using previously recorded sound effects to enhance or replace sound effects recorded on set) work that can be done to add things like footsteps and doors closing.

All of these things assume that you, as a producer, will have access to: a recording space and equipment for ADR, as well as actors who will be available for ADR sessions, sound editing software and possibly hardware, with someone who is capable of operating all of it, and lastly, money to pay for this, or people willing to do it for free (and do it well.) But what if you don’t have access to these things?

Sound can be captured fairly cleanly under the right conditions and with the right equipment, but there are many elements that have to be considered if you want to save time, money and energy in postproduction.  The simplest, is to plan your shots with sound in mind.  Know what equipment you will have available, know your location, and plan your shots accordingly.  I have been in numerous situations where camera setups have made it impossible to properly capture sound, especially when no wireless mics were present. This isn’t an issue if you can ADR it later, but you should definitely consider this if you can’t or don’t want to, since ADR has its own drawbacks, which I will explain later.

2. Location Scouting:

Location scouting is incredibly important for camera work, since it lets your DP (Director of Photography) know ahead of time what kind of light there will be, or will be needed, as well as how much space is available.  However, location scouting is just as critical for sound.  Often, this step of preproduction is done before a sound person is hired on low budget shoots, but you (or whoever is scouting) should still find a way to bring a microphone and a good pair of headphones (ones specifically designed for production work, and not for listening to music) to listen to the location.   The location scout should be listening for things such as traffic, planes, ambient noise, echoes and reverb.  The scout should be done at the same time of day that you plan on shooting, as locations can sound (and for camera, look) differently at different times of the day. Camera work should still be the priority during the scout report, but if you want to avoid problems later, don’t forget about sound!

3. Equipment and Sound Crew

In the modern age of filmmaking, there are a lot of relatively cheap alternatives when it comes to film gear.  Sound is no exception.  On professional shoots, sound gear could comprise of multiple boom poles, multiple microphones for said poles, multiple wireless lavaliers, a massive mixer and recorder, sound blankets, wireless monitoring, production headphones and more.  For a low budget shoot, almost none of this is necessary.

Let’s assume you are shooting on a camera that has XLR inputs for sound (XLRs are audio cables used in production. They are typically three-pinned, but there are other varieties as well.  XLR is not a proper acronym.  It has simply been adopted to describe the cable). By using XLRs, you can record audio directly into the camera, which eliminates the need for syncing sound in postproduction and the need for a field recorder (which I will define below).  The most basic things you are going to want are a boom pole (with a shock mount), a field mixer, and a microphone.  Now, I have seen shoots of varying levels of production where a sound person isn’t even present, and the camera operator doubles as a sound op (operator).  In these situations, a microphone is usually attached to the camera and the camera operator adjusts the audio levels beforehand, and monitors the audio with headphones while filming.  This can work for documentaries, where natural sound is acceptable, and subtitles can easily be edited in should the audio get messy, but for narrative films, you are really going to want a sound person and proper gear.

One of the key pieces of equipment is a field mixer.  A mixer allows you to adjust the audio levels before they are recorded.  Mixers will also typically have filters that allow you to cut out certain frequencies of noise (such as mechanical hums or rumbling) as well as peak limiters, which prevent the distortion of audio that is caused when the level is too loud. In a best case scenario, you wouldn’t need to use these features often, if at all.  You generally want to capture the most natural sound you can, applying the least amount of filtering before recording, since post production software and hardware is often more powerful, Mixers come in many different sizes and shapes. More expensive mixers will often offer better features to the sound op, such as having more input channels (allowing more microphones to be plugged in) and generally better quality, but on a tight budget, you can get by with cheaper mixers. Two input channels and two output channels are good enough for most micro-budget shoots.

Field recorders are very similar to mixers in function, with the exception that they can record sound.  They often have the same features, though cheaper models are less suited for adjusting audio levels on the fly.  More expensive recorders can actually double as mixers.  When using a recorder, you will need to sync the sound in postproduction.  This means that you will need to use a proper slate when shooting in order to sync it later.  The slate is the board with the scene information (and timecode, if it is a more expensive model) that has the clapping stick on top.  The clapping produces a sound that is very loud and easy to see in the editing software.  The lines on the clapper part give a visual reference to the editor so that they can sync the audio spike from the clapping of the stick with the video frame in which the angled, black and white strips on the sticks converge and form a solid arrow pattern.

Whether recording to a field recorder, or directly to a camera, one thing remains important, and that is monitoring your audio.  You should always be monitoring the audio from whatever is actually recording, be it the camera, or a recorder.  If your headphones cannot reach the camera, at the very least, get an extension.  But you really should invest in an XLR cable that will include headphone jacks that will allow you to plug into the camera and still monitor its audio from the field mixer (mixers typically have two monitoring channels, one for the mixer itself, and another labeled AUX or Tape, for monitoring from the recording device).  Break out cables (a.k.a. Fan out cables) usually have this capability, but can often be overly complex in that they can have several different connection types on one cable.  Just be sure to look for one that has the connections you need for your production.  The simplest one will likely only have two XLR heads, and a headphone plug.

Production headphones are a definite requirement for accurate monitoring.  Production headphones are different from the headphones you’d normally purchase for a stereo system or an mp3 player because they are built specifically for monitoring sound, rather than for entertainment.  Some music-based headphones will be built to purposefully boost the bass or some other frequencies for a better musical experience, but monitoring headphones are designed to be balanced and accurate.  Be sure to look for headphones labeled as “production” or “studio” or “monitoring” headphones before purchasing.  A safe bet is Sony’s production series of headphones.

Boom poles can be fairly cheap, with a decent one costing around $100.  You have to be careful with cheap boom poles, however, since they can be less sturdy, and can produce unwanted handling noise. A good boom pole might cost $300-450 but it’s worth it since they are usually much sturdier.  Boom poles made from lighter materials also tend to cost slightly more, but can be more comfortable to operate.

Shock mounts are what attach the mic to the boom pole.  They are meant to prevent the movement of the pole from affecting the microphone by allowing it to essentially float freely.  A decent mount will be about $50.  Cheap mounts often have rubber-band-like pieces that snap or don’t provide a good enough cushion for the microphone, producing unwanted noise when moving.

There are many types of microphones available.  The two most important types are cardioid mics and shotgun mics.  Both of these are mounted on the boom pole, and they both have their own strengths and weaknesses.  The shotgun is the most typical mic you will see requested or used on a low-budget set, because of its versatility.  By design, it is actually not always the best mic for the job, however.  Shotguns are highly sensitive.  Their “pick up pattern” (think of an invisible field that extends outward from the mic that captures sound) is very narrow but also longer than other microphones, meaning you can boom from further away, which is nice for wider shots.  A good shotgun mic will be great outdoors and will be usable indoors; however, the disadvantage to using it indoors is that you run the risk of picking up unwanted background noise that is bouncing off of structures in the space, due to the mic’s sensitivity.  Cardioid mics, which include Super and Hyper Cardioids, have a similar directional pick up pattern to the shotgun, but theirs is generally a bit wider, with shorter ranges.  Hyper and Super cardioids are narrower than regular cardioids.  The cardioid mics in general are really great for working indoors and picking up dialogue.  They are also much more forgiving to boom with, thanks to the wider pick up pattern.  In an optimal situation, you can pick and choose between the types, but if you can only have one, it would probably be safest to use a shotgun, unless you are primarily shooting indoors in a relatively quiet space. Omni-directional mics are capable of picking up sound from a very wide area, which works out great if you need to capture the sound of a group of people in a space at the same time.  This kind of mic is rare to see on low budget shoots because its uses are very limited, due to its lack of directionality.  Omnis can sometimes be found on cameras themselves, though some come with cardioid types as well.

The mics that come built into a camera shouldn’t be used as your main source of sound for a narrative film because they will almost never be in the optimal position to pick up good sound, and because more often than not, they will not be the right mic for the shot.  On documentaries, cameras with more directional mics mounted on them can be quite useful for on the move shooting. Even then, however, mics are usually attached via a special mount, rather than using the onboard microphone.  This is because onboard microphones usually don’t have the range or sensitivity that other types of microphones tend to have.  Additionally, this lets you switch mics if necessary.

After choosing a microphone for your boom pole, you need to have wind protection.  The basic foam covering that is likely to be included with a new microphone will work indoors.  If you move outdoors, however, you will need to purchase additional protection.  The cheapest alternative is to buy an additional furry covering that is placed over the foam.  This provides the minimal protection for the lowest price.  It’s quite useable, though stronger gusts will be picked up.  The next level of protection comes in the form of slip-ons that completely replace the foam covering, rather than supplementing it.  These provide greater protection by way of a nice rubber stop at the rear that aids in protecting wind from sneaking in around the covering.  Slip-ons can be soft and fuzzy, or smooth and more rigid.  Most typically, you will see fuzzy coverings, since the fur aids in the blocking of air.  The most expensive method generally used for boom mics are the full blimp and zeppelin systems.  These tend to be quite expensive, since they completely encase the entire microphone in a wind free chamber, and come with their own mounting system for the pole. Additionally, they are often supplemented with an optional fur coat, commonly referred to as a “dead cat” (due to its relative size, shape, and coloring) for extra protection.   Whichever you choose, it is important to make sure it fits your microphone, as different types of mics from different brands can have varying dimensions.

Wireless lavaliers (also called lavs) always seem to be a favorite of producers, but the fact of the matter is they are almost never necessary with proper planning (for low-budget narrative films).  Lavs are fantastic to have access to, but good lavs are expensive (at least 800$ per single lav/receiver/transmitter set) and cheaper lavs can cause more problems than they solve.  Many times producers seem to prefer lavs to booms, since it saves space and seems to be more efficient, but this is not really the case.  Even with good lavs, there is always the chance of a signal issue, but more importantly, there is the matter of sound quality. The sound you capture from a mic that is planted directly on an actor/documentary participant is very different from the sound that a boom mic a few feet away will pick up.  Boom mics do a much better job of replicating a more natural sound since the sound is allowed to travel through the air and mingle with ambient noise.  Planted lavs, on the other hand, are right on the actor/documentary participant, frequently against their chest, which results in a very different quality.  Again, with proper postproduction, this doesn’t matter as much, but it is something that should be considered when planning a film. I should also point out that this it not really an issue when it comes to documentary filmmaking. With narrative filmmaking, it is of the utmost importance to record clean and consistent sound throughout the shoot.  This allows a sound designer more freedom in post to create an atmosphere of their own, and giving them the opportunity to evoke emotions in the audience with audio cues.  Documentary filmmaking is usually more concerned about capturing the reality of a given situation. Some things which may not be acceptable in a narrative film, such as background noise, may work in a documentary. However, it is ultimately up to the director to decide what kind of sound they want for their film, regardless of what type of film it is.

The most optional piece of equipment, and one that you will almost never see on a low budget shoot, is a sound blanket.  The sound blanket is literally a blanket made from a dense material that allows it to block sound.  They come in various sizes, and are generally used to block sound coming from a window, or to block sound from a doorway that can’t be closed, or even to cover sound coming from specific objects, such as a fridge, in the area.  These are a rarity, however, due to their cost.  Location scouting would be the number one alternative to this, and it costs less.

The last significant piece is the sound crew itself.  There are two points I would like to make regarding two common mistakes producers tend to make with regards to finding a sound crew.  The first is the idea that anyone, whether they be a PA (production assistant) or intern, can boom.  True, if they went to film school, and took some basic production classes, this might be the case, but booming can be pretty difficult and in some cases, physically demanding.  There are right and wrong ways to both hold the pole and move with the pole, not to mention taking care of the equipment in general.  That being said, I have almost never had the luxury of working with a boom operator.  It is completely possible for the sound recordist/mixer to also be the boom operator, but there are some physical limitations to this, and if it can be helped, you should probably not have them doing two important jobs at the same time.   Again, this has more to do with narrative filmmaking, than documentary filmmaking, where it tends to be easier to do both at the same time due to the nature of on-the-go-filmmaking that documentary films espouse.

The second point deals with finding a recordist/op/mixer.  Many job postings ask for reels for these positions.  This is a mistake.  A sound recordist who is not also a postproduction sound editor isn’t going to have a reel that will be indicative of anything they do on set.  Location sound that is unedited is almost never going to sound as good as the stuff you hear on TV or in a theater.   Furthermore, the sound on location isn’t entirely within the realm of control of the sound crew.   Their job is to record usable sound on site.  Unless you are interviewing a sound editor, you really shouldn’t ask for examples of raw sound from a sound person.  The gear they own, their credits, references, and any links to finished works they have should be enough for you to decide whether to interview them or not.

4. Post Production

The last piece is the postproduction phase.  Good sound draws you in, and doesn’t call attention to the fact that it has been recorded on a microphone.  Getting good sound on location can do wonders, but even then, you are going to need to give it a pass through sound editing software to clean it up and adjust the levels, so that, in general, everything is at the same clear, understandable level.  This prevents some scenes from being too loud and others from being too quiet, even though in both cases, the actors/documentary participants are in similar locations and talking at similar levels.  It also allows you to adjust certain frequencies for better sound quality.  Additionally, certain background noises can be cleaned up with the use of filters.  All of these things are necessary if you want a clean-sounding film. There are other things that can be done in postproduction, such as foley work or ADR.  Foley work provides better control over the sound design by allowing you to play with sound effects (such as cars driving by, water running, etc.).  ADR should be avoided if possible.  It is difficult to do without the right equipment and it can be tough to get performances from actors or documentary participants that are as good as what they would deliver on set when they are stuck in a booth weeks or months after shooting has ended.

I would like to point out how important location sound is on a narrative film project.  Especially on a low-budget project where you want to prevent having to fix as many things in postproduction as you can.  With some basic planning, you should be able to get functional sound without significant costs (a basic sound package, without wireless components, could easily fall around $2000, which would include a mixer, boom pole, boom mic, XLR cables, shock mount and wind protection).  It is definitely an investment worth making.

Equipment Glossary:

ADR: Automated dialogue replacement, which is the act of rerecording or “dubbing” over lines for better clarity in postproduction.

Blimps and Zeppelins:  Blimps and Zeppelins are a type of wind protection that completely surrounds the microphone in a small chamber.  These can be, and often are, supplemented with an additional furry covering for extra protection.

Boom Pole:  An extendable pole used for mounting a microphone and reaching a source of sound from a distance.

Cardiod Microphones:  Cardiod microphones are similar to Shotguns in that they are directional and are typically mounted on boom poles for production.  They are less sensitive and are less directional, which means the mics must be closer to the subject and that they are capable of picking up sound from a wider area in front of the mic.  Super and hyper cardiod mics are more sensitive, less directional variations.  Great for indoor shooting and for picking up dialogue.

Field Mixer:  A device used to adjust the audio levels and ensure good quality sound before it is recorded.

Field Recorder:  A device used to record sound.  Some recorders are also capable of acting as mixers.

Foley:  Recording or using previously recorded sound effects to enhance or replace sound effects recorded on set.

Production Headphones (Monitoring Headphones): Headphones designed for monitoring sound.  These are different from normal stereo headphones in that they do not boost the sound in any way.  Rather they are meant to give the listener a clear and accurate monitor for the audio.  Stereo headphones often have features that boost the bass.

Shock Mount: An attachable head for the boom pole that holds the mic in place and prevents handling noise by absorbing and dampening the movements of the boom operator.

Shotgun Microphone:  A type of microphone typically mounted on a boom pole.  Shotguns are usually very sensitive to sound, and can pick up sound clearly at distances up to several feet away.  They are also directional, meaning that they only pick up sound clearly that is directly in front of them.  Sounds off to the side will not be as clear, and sounds from behind the mic will be barely audible.  Good for outdoor shooting.

Slate: A device used to aid in syncing sound in post.  It functions by using a striped clapper to produce a loud audio spike, as well as a visual reference for the editor to sync together in post.

Sound Blanket:  A blanket made from a dense material that is used to help block sound from unwanted sources.

Wind Protection:  Wind protection is a necessary form of microphone accessory when filming outdoors (or in any place with some kind of moving air current.)  The default foam covering that comes with most mics rarely provides adequate wind protection and will at the very least need to be supplemented with additional furry covering.  Better protection comes from slip on coverings and full blimp and zeppelin systems.

Wireless Lavaliers (Lavs):  Wireless microphone systems typically placed directly on a subject’s body or clothing.  They allow for the capture of audio in situations when a boom pole cannot reach.

XLR: Audio cables used in production.  Typically three-pinned, though there are other types.  The term XLR is not an acronym, but rather an evolved nickname for the cable.

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