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Posted by on Oct 22, 2010 | 9 comments

Aaron Marks Special: A Practical Guide to Field Recording [Part 1]

Field recording is defined as any recording made outside of a controlled studio environment.  So, pretty much any audio recording you make whether it’s in a garage, your backyard or out in the middle of nowhere is considered field recording.  Recording inside a studio is already challenging enough, but add in portable equipment, wind noise, airplanes, birds and all of those unpredictable annoyances and you’ve got yourself a real challenge!  If you enjoy fresh air, meeting interesting people and doing things that can be down right fun, then field recording is definitely for you.

The purposes of field recording

There is a quite a variety of reasons for sending recordists and their gear into the ‘field’.  Film and TV productions, newscasts, sound effects libraries, games and even music production all have dedicated professionals who’s task is to capture clean audio no matter what the situation. Working as a field recordist can put you in a wide range of situations and all with some definite challenges.

  • As part of a film or TV production crew, the field recordist (also referred to as ‘sound recordist’ in this case) is not only expected to record actor dialog and specific sounds that may be happening in a scene, but to record ‘on location’ sounds for later sound design, location ambience and room tone for Automated Dialog Replacement (ADR).  Each of these tasks requires a specific thought process and sometimes different equipment to accomplish successfully.  As part of a location sound team, the variety of recording activity and the pace of the shooting schedule will keep you hopping.
  • Live action news teams typically have a dedicated sound recordist who’s job is to make the on-air talent not only sound good but to record ‘story’ related sounds as well.  If the focus of the segment makes a sound, it’s a good idea to let the audience hear it.  These folks often find themselves in wildly unpredictable and uncontrolled situations as they chase down dramatic news stories.
  • Sound effects libraries have to be recorded by someone and this is one instance where field recordists really get to show off their skills.  Recording everything from ambience to explosions, crickets to jet aircraft, there are plenty of noise making objects to be collected and cataloged, so there is plenty for these folks to do.  And knowing fellow sound designers will be listening very critically and using them in their work is a great motivator to get it right.  Plus having a viable and usable collection of sounds is a nice feather in your cap.
  • Games require fresh sounds for practically every production.  Ambience and sound effects are the main focus of field recordists in this corner of the industry as they’re often found pointing microphones at typical subjects like weapons, exotic cars, military vehicles, aircraft, animals and junk yards.  These sounds are collected to be used ‘as is’ or as elements in the sound design creation process – so no sound is a bad sound.
  • Music production is a little known venue for field recordist but one where they can play a major role in a performance.   For in-studio productions, ambience or sounds which help support the ‘story’ are often used, especially in the ambient genre, and non-musical sounds can be used as musical elements in beats or as percussion.  Recorded live music productions will typically require audience reactions as well as location related sound needs for television simulcast and future CD/DVD releases.



There are a wide variety of opportunities in field recording, and whether you focus on one specific corner of the profession or become adept at them all, your skills and talents will play a major role in any production. And, with the variety, you’ll find yourself placed in exciting situations and always challenged – plus, the pay isn’t bad either.

Field recording prep

Before running  full throttle into the great unknown, it’s wise to take a moment of pause to evaluate what you’re facing and plan for every contingency. It can be incredibly difficult choreographing the intricate ballet of the logistics involved to not only get the recordists and equipment to the field but scheduling the location, finding and gathering the recording subjects (such as tanks, exotic cars, weapons, etc) and their special needs, that you can’t take the preparation phase too lightly. There’s nothing worse than having one cog in the wheel derail the entire session , so this is the time to ensure you’ll be able to get what you came for no matter what.

Here’s a few things to consider before recording day:

Define the objective of the recordings. Identifying the purpose of the sounds and how they will fit into the production will help get your planning off to a good start. Will the recorded ambience playback in surround? Is the car engine you’re recording a ‘signature sound’ that will be front and center in the production? Is the sound meant only as a low priority item which will be buried under explosions and gunfire? Knowing the sounds importance, priority and use within the project will determine the amount of effort needed to capture it. Also knowing whether the sounds will be recorded for a big budget flick or for a cell phone game will also provide appropriate direction.

Define the sounds needed.  Make sure you have a solid list of required sounds before making any plans since these will determine your equipment needs, recording techniques, crew and location. Most field recordists like to take advantage of the access they have to a subject and will typically record every sound that object can make while it’s sitting in front of them.  But, a tight budget and schedule can preclude any extra recordings other than what is specifically needed. If you only need to collect static vehicle sounds, for example, then you won’t need to worry about how to record the vehicle as it blazes down the road at 100 miles per hour. And if you did need sounds of an exotic car traveling at high speeds, you’ll need to find an appropriate place to make that happen – a safe place where the drivers can open ‘er up, that is relatively quiet and within budget. Knowing what specific sounds you need will lead you another step closer to the big day.

What is the available budget? Budget constraints will affect the equipment you rent, the size of your team, the location you use and a myriad of other factors. Knowing what you have to work with will help balance these factors against obtaining quality recordings and a decent paycheck. Recording in your backyard with your own car is one way to satisfy the needs of a low budget project. The opposite end of the spectrum will allow for track rental, suped-up vehicles with professional drivers, a team of experienced recordists and top-notch equipment. Either way, your challenge will be to remain within the budget and grab great sounds.

What equipment do you have available?  Take inventory of the field recorders, microphones and all of the accessories you have access to early in the process. Your collection of gear will grow for each project but only having a Zoom H2 on hand to record gun shots might not have the best results. Factor equipment rental into the budget if you need but exhaust your on-hand gear first in an effort to keep the ‘to-do’ list short. Knowing what you have to work with will help determine recording methods and your plan of attack ready for D-day.

Anticipate the recording conditions and scout the location. Having some idea whether the location of choice will be acceptable is definitely something you need to know before the day you show up to record. Even if you plan to head out to the middle of nowhere, it’s no guarantee there won’t be issues. Is it under a busy flight path?  Is it a popular area for off-roading? Is there wildlife, especially birds and insects, who might pose noise challenges? If you happen to be renting warehouse or shop space, are there local businesses that might have noisy equipment running? Don’t forget the weather forecast too. Rain, wind or temperature extremes will be a definite factor. Check out your location beforehand, and if you have to, find another place, day or time to record. If you are stuck with it, though, you’ll be a step ahead and can plan accordingly.

Plan for necessary staff. If the field recording session calls for a single person ‘running and gunning’ or several crew members to cover all of the bases, it’s a good idea to think the process through and decide in advance. Too many folks standing around tend to be a distraction, too few puts undo pressure on the crew on-site. As a good rule of thumb, make sure each person has a specific duty to perform and reason to be there. One person should be ‘in charge’ as the recording supervisor. Specific recordists who focus on capturing the best audio and handle the gear and should be appointed. Larger sessions might require assistants to set up mics, run cable and control curious onlookers. Sessions which have an element of danger, such as when recording weapons, explosions or heavy machinery, it’s a smart idea to contract a medic or ambulance service depending on the risk. Additionally, having a consultant on crew who is highly knowledgeable about the subjects you are recording will ensure you get what you came for and are usually worth their weight in gold.

Equipment choices

Once you have an idea of what you’re hoping to record, the equipment you may already have available, the proposed location, a budget and a crew, it’s time to decide what you really need to make it all happen. Like a combat unit choosing weapons, ammunition and supplies based on their mission, developing a mindset that you are in fact heading into ‘battle’ will ensure an excellent probability of success. The choice of microphones, recorders and accessories can make or break a recording session and nothing is more heartbreaking than showing up in the field with the wrong gear. Remember, you don’t have to own all of the gear you use and it’s typically more practical to rent.

Field Microphones

Microphones come in all shapes and sizes and having the right one pointed at the sound can make a huge difference.  The most expensive one isn’t always the best choice and the one that is perfect won’t always be practical. Field recording can often be a bit of compromise as you evaluate the conditions, sounds and equipment, the microphone you pick for any given situation can either solve prevalent issues or make them worse. Remember, sometimes microphones are chosen specifically for what they can’t hear rather than what they do.

Let’s face it, there are so many types of microphones to choose from that it becomes a real effort to find the right one for each situation. Most field recordists have their ‘go to’ mics, the ones they grab first whether it’s because they like the way it colors the sound or because they always have good luck with it. But, until your experience guides you, there are more scientific ways of choosing a useable mic for a given challenge.

Microphone types

There are basically two distinctions of microphones – ‘type’ and ‘polarity pattern’. ‘Type’ refers to the physical construction and characteristics of the mic, ‘polarity pattern’ describes how the microphone hears sound. Both have equal influence when deciding what is best for a given situation and should be given close consideration when making your choices.

Types

  • Stereo - These types of microphones are designed to capture a stereo image using a standard XY pattern, MS (mid/side) or matched pair configuration.  These are great for ambience and sound effects when required in stereo format.
  • Shotguns - From short shotguns to long, mono and stereo versions, these mics capture a narrow focused image of whatever sound it is pointed at and reject sound to the sides and rear.  These are perfect for recording dialog during a scene or any other sound that needs to be brought ‘closer’ or separated from other sounds.
  • General purpose - Utilitarian microphones which can be used in a wide variety of situations, these are great for general sound effects, voice and any other instances when a mono format is desired.
  • Lavalieres - These tiny microphones are designed specifically to capture voice in a variety of situations but their small size can be useful for other applications when the size of another mic is an issue.
  • Dynamic - These mics are generally robust, inexpensive, resistant to moisture and can handle sounds with heavy attacks, such as gunshots and snare drums with ease.  Their sensitivity doesn’t allow them to capture quiet sounds well but are great with loud sounds.
  • Condenser - Capable of capturing very quiet sounds, these powered microphones are perfect for whispers, quiet ambience and other sounds where their subtle nuances are desired.
  • Miscellaneous - In addition to the standard field microphones, other mics offer solutions to very specific needs.  Contact mics record the vibrations of an object and are not susceptible to issues ‘sound wave’ capturing mics do.  Hydrophones are specifically designed to record sounds in liquid.  Binaural microphones simulate how a person would hear a sound, typically a ‘head’ and microphones for ‘ears’.  Surround microphones have six mics placed in an array to capture sound from each direction for playback on a 5.1 system.



Polarity patterns -

– Omni-directional – The omni pattern has a equal response at all angles with a full 360 pickup angle. These mics have a very natural sound and are good if the room or space ambience is desirable.

Use omni-directional:

  • Where the sound source to microphone distance is small so that the fact that it is non-directional does not cause a severe disadvantage.
  • Where the source is a ‘talker’ and the mic can be very close, right in front of them.  This type is less susceptible to popping and no bass boost (proximity effect) from close use.
  • When wind is a significant problem.  Pressure-sensitive microphones respond much less to wind noise than directional or velocity sensitive mics.
  • Because of the requirement for a small size such as a lavaliere or planted mic.
  • When multiple, spaced omni’s are used in one type of stereophonic recording – useful with certain large-scale effects such as a train moving past the array of mics.



– Cardioids – The unidirectional pattern is most sensitive to sound arriving from the front of the mic and much less from the rear.  The most common type is the heart-shaped pattern and should be used if a more isolated pick-up is desired.

Use cardioids:

  • When the sound field can be differentiated into desired sound coming from one direction and undesired sound from 180 degrees away such as placing a mic near a speaker on a busy street and pointing the mic at the talker and the back of the mic to the street.
  • Note that cardioids, while the most common type of directional mic, are not widely used in film making (as in music recording or public address systems), hyper- and super-cardioids are used to discriminate against noise and reverberation in these cases.



– Super/hyper- cardioids – Unidirectional mics come in other variations like the super-cardioid and hyper-cardioid.  These have a very focused pattern and are used when the source is far away or there is a lot of ambient noise to deal with.

Use hyper- and super-cardioids:

  • When you want to discriminate against reverberation and have a mic with a relatively small size.
  • Where the source of noise can be placed in the null zone between 110 to 126 degrees from the front and the desired source is on axis such as on a boom capturing an actor on-mic and placing the camera in the ‘null’ – typically with noisy film cameras.
  • These considerations lead to the selection of these mics for boom use.



Use short shotguns:

  • For greater discrimination against reverberation and noise at high frequencies although they are equal in bass and mid range frequencies.
  • When, if the actor/event is moving, a boom operator can’t accurately aim the mic because of poor off-axis sound.
  • The most often used boom microphone.



Use long shotguns:

  • For the greatest discrimination against off-axis sound over a wider frequency range than the short shotgun.
  • Outdoors, for wide shots, dolly shots and when the sound source is further away than normal.
  • Indoor use is not generally recommended because the interaction of the complex polar pattern of this mic type with room acoustics leads to coloration.



Microphone selection factors

Unfortunately, it takes much more than simply picking a type and polarity pattern for the perfect mic to stand out – although it is a good start. How do you plan to mount the mic? What are conditions like on location? Are there any weather extremes which might be a concern? Answering appropriate questions which are specific to your mission will help you close in on the right equipment.

  • Visible characteristics. The size of the microphone can impact the decision if it must be carried all day or if cramped space requires something small.  For example, large microphones are difficult to mount inside of an engine compartment when gathering vehicle sounds under driving scenarios – a lavaliere would make better sense than a long shotgun.  Additionally, the method of mounting the mic may be a factor if a shock mount, mic stand, blimp, boom pole or gaffers tape are used.
  • The method the mic uses to change acoustic energy or ‘sound’ into electrical energy. There are advantages and disadvantages to using pressure or velocity sensitive mics, especially when wind noise is a factor. Contact mics are an entirely different sort of mic in this respect and are able to capture sounds from an interesting, non-sound wave perspective.
  • Directional characteristics (polar pattern). Whether you intend to collect sounds from a full 360 degrees around the microphone or from a focused area, the polar pattern selection is not only chosen because of the direction of the wanted sound but often as a way to minimize unwanted sounds.
  • Susceptibility to wind and handling noise. Wind is by far one of the biggest challenges of field recording and having a microphone which is able to ‘ignore’ its effects can sometimes save the day. Wind covers and other accessories can be effective but sometimes the right microphone makes all of the difference. Many field mics come with a ‘low cut/high pass’ feature as well which can minimize wind and handling noise.
  • Coverage of the frequency spectrum without discrimination. Microphones are designed to be as generally flat in their frequency response as possible but due to their construction and circuitry will have bumps or dips in various spots along the spectrum. If the fundamental frequency you are recording is within the ‘flat’ portion of the mics frequency response, then you can expect no coloration unless that is what you’re looking for. Other interesting ‘features’, such as with some lavaliere microphones, have a bump in the higher frequencies to actually compensate for these mics hidden underneath an actor’s clothing.
  • Coverage of the polar pattern across the frequencies. Unfortunately, frequency response isn’t always consistent throughout the entire polarity pattern of the mic. This isn’t so much a concern when using a shotgun mic, for example, but if the desired sound covers a wider area such as in ambience recordings, a better representation can be captured if the frequencies are constant throughout the entire pattern.
  • Power requirements. If the microphone of choice requires power, this added condition will need a reliable source.  Some mics utilize internal batteries or can be powered from the recorder with phantom power, neither of which will impact a mobile setup other than restricting your choice of recorders.  Others that require a separate power supply might influence your ability to stay mobile.  Ensure the power requirements don’t hamper your capabilities.
  • Susceptibility to temperature and humidity. Extreme hot or cold conditions can not only affect the human equation but the gear as well. Batteries tend to become unreliable in cold conditions and equipment that usually runs hot increase the chance of damage or failure. Also, the overall sound and capabilities of a microphone, especially the delicate diaphragm when heated or cooled, can color the sound in ways that can make you cringe. If your location is going to be a challenge, research the equipment that can withstand the temperature and use it.
  • Ability to handle loud and soft sounds. Recording sounds with a large dynamic range can test even the most experienced recordists. It’s challenging enough to record strictly loud or soft sounds on their own but when sessions are mixed, such as when recording gunshots and weapons Foley, microphones which can record both equally as well is a plus. Knowing what types of sounds you’re heading out into the field to record will ensure you take the mic that can handle both extremes when needed is a good thing.
  • Ruggedness. Studio mics are typically more delicate due to their need to capture the smallest nuances of instruments and vocals, and that’s not to say you couldn’t take some nice large diaphragm condensers to the field if needed, but why bother if the mic can’t take the more demanding conditions? Ensure the mic selection is robust enough to handle the journey, being mounted to a vibrating, jostling vehicle, for example, and being knocked around by overly aggressive ninja recordists.
  • And finally, how the mic sounds. Unfortunately, how the mic sounds can’t always be the first reason to choose one but it should weigh in as part of your decision. Some mics sound REALLY good no matter what you point them at and if they meet other criteria in your list, then these should be part of your arsenal. If you have several which are worthy, always choose the one which will capture your sounds the cleanest and in the highest quality because after all, you’re reputation and future employment possibilities are on the line.



More coming up! Part 2 will continue with recorder choices, field recording accessories and recording techniques.

Written by Aaron Marks for Designing Sound.

9 Comments

  1. Fantastic read, it has helped me write a check-list for an upcoming project. Look forward to part 2.

  2. You could add “radio documentary” to the “Purposes of Field Recording” section… it’s a combination of sound design, film/tv production, and news gathering!

  3. Hah, some wording is slightly strange here,
    heading into battle?
    Really?

    M.

  4. sometimes you may be heading into battle actually-

  5. ‘Battle’ may be a bit of artistic license on my part… but because of my military background and how we have to literally ‘fight’ to capture some sounds… plus the furry weasel guns we use…. seemed like the best reference. :)

    And Rob – yes, you’re definitely right – audio docs are certainly another purpose – don’t know how I forgot to mention that… especially after my last weeks class lecture was on that very thing!

  6. This is an invaluable source of information for beginner sound designers like me! Thanks for sharing, I love this website. :D

  7. thank u Aaron Marks so so so much for sharing such valuble information.

    • Thanks for the heads up!

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