location sound - the basics and beyond

Location Sound: The Basics and Beyond

http://www.kenstone.net/fcp_homepage/location_sound.html[20/08/2009 20:38:39]

White Paper - Location Sound

October 21, 2002

Location Sound:The Basics andBeyond

By Dan Brockett

The First Link - Sound Itself The Second Link - Microphones The Third Link - Cables and Adaptors The Fourth Link - Mixing and Routing Devices The Fifth Link - The Recording Device The Sixth Link - The Monitoring Circuit of the Recording Device

Let's Discuss Sound For Picture The concepts of location sound recording that we will discuss in this articleare basically the same, whether you are shooting your tenth independentfilm or your first project with your first new camcorder. Audio seems to beone of the most challenging areas for beginners and even experiencedfilmmakers alike. Video professionals typically find sound one of the mostchallenging aspects of production. Ten years ago, producing professionalquality film or video was a much more cut and dried process. If youwanted decent sound for your picture, you either had the knowledge andequipment to record it yourself or you hired a location sound team. This isstill true today but the differences are that there are a lot more peopleproducing video today who may not have experience and skill in recordinglocation sound than there were ten years ago.

DV users with many different experience levels and widely diversebackgrounds are producing their own projects. The fact is that almost all ofthe tools needed to produce broadcast quality video and DV "films" havebecome relatively inexpensive and widely accessible. Final Cut Pro andAVID Express DV both have about 90% of the capability of a $100,000.00AVID Media Composer system at a minute fraction of the cost. Camcorderslike the Sony PD-150, Panasonic AG-DVX100 and the Canon XL-1S arecapable of producing extremely high quality images.

PD-150 AG-DVX100 XL-1

mailto:[email protected]



The immense popularity of digital video means that a large majority ofusers today have access to the most advanced communications mediumsociety has ever seen. We have small, relatively affordable, high qualitycamcorders that can make amazing images with far less light than everbefore. We have very sophisticated and capable video editing toolsavailable on both platforms. Assuming we all want to produce work ofquality, what's missing from this equation? You guessed it, the sound. Thefact is that most independent, low/no budget projects that are producedtoday seem doomed to suffer with sound that ranges from merely averageto barely usable. Whether you are producing video for your friends andfamily, to view, weddings and events, corporate audiences, or forbroadcast or theatrical release, no matter which category your audiencefalls into, they expect "transparent" sound from your project's soundtrack.Let's define what "transparent" sound is.

Audio conveys almost all of the emotional impact in thevisual medium. It's a fact. If you watch your favoritescene from any film or TV show with the sound off, yousoon discover that moving images on their own aretypically not very emotionally involving. Don't forget,silent films could be scary, sad, happy, dramatic orinteresting BECAUSE they were conceived withoutsound. To be totally fair, most silent films were viewed with either live orpre-recorded music. Obviously, most of us want to produce projects thatwill emotionally involve our audience. For most of us, video has becomethe single most common collective vocabulary in our lives. It is also agiven that video is great for communicating almost any message to almostany audience, if done well.

The Experience Economy What may be less obvious to you if you are new to film and video making,is that audiences of all kinds now expect to be entertained while you areconveying your message. If you are in the entertainment end of thisbusiness, this is understood, but for those of you who want to createhome video, weddings, events or video for business, your content mustalso be entertaining and compelling. Emotional involvement from youraudience is what defines good entertainment. You may not feel that theShop Safety training video you are producing can or should be veryentertaining, but if the production values and concept are not very highquality, your training video will bore your audience. If it's done well, evena Shop Safety training video can be entertaining. Your sound is largelywhat will determine if your project is entertaining to your audience. Unlessyou want to conceive your project as a "silent film", you have to beconcerned ('obsessed' might be a better term) with your project's sound.

One of the toughest concepts for many newer DV users to grasp is thatthe better job you do with your project's sound, the less it will be noticed.I feel that this concept is one of the reasons why most projects don't endup with very high quality soundtracks. We are very used to spending time,effort and money on a better camera, lens, bigger and better lighting, crewand visual effects and seeing an immediate "payoff" when our images are



viewed. It's instantly recognizable if a scene is lit effectively or if a visualeffect is done well. We feel "justified" in shooting on a higher quality, moreexpensive format or with a bigger crew because the end result is usuallyeasily identifiable on-screen. Most of us can immediately recognize if aproject was shot on 35mm film versus DV or if a project's motion graphicsor visual effects were well executed. If we notice a sound mix though, it isusually because the sound was done incompetently. This is the centralconcept of "transparent" sound. If your location sound is recordedcorrectly, the easier it will be to work with the basic audio during the post-production process. The better job you do with the sound during video andaudio editing, the less the audience will notice it. The only sound that isnoticed in a visual medium is usually poorly executed. Great sound workson a subconscious level with the viewer by drawing them into what theyare viewing. Great sound supports and enhances the stories you are tryingto tell. Now that we have a basic understanding of the goal for yourproject's soundtrack, let's review what we have covered before we diveheadlong into equipment and technique.

Four points to remember about sound for picture

1 . The principles of location sound are the same for almosteveryone shooting anything.

2 . No matter who the audience is, at the very least, they expect"transparent" sound

3 . Sound conveys emotion - picture conveys information

4 . The better your soundtrack, the less it is consciously noticed

It's All Just a Chain The easiest way to discuss location sound is to think of the entire audiopath as a chain. In the case of location sound, the "links" are:

The sound itself

The microphone(s) that capture the sound



The cables and connectors that carry the signal from the microphoneto the mixing or routing device and from the mixing or routing deviceto the recording device

The mixing or routing device that carries the signal from themicrophone to the recording device

The recording device itself (typically a camcorder but could also be aVTR, Hard Disc Recorder, MD or DAT recorder)

The monitoring circuit of the recording device

Just as in an actual chain, the audio path is only as strong as it's weakestlink. This means that a high-quality, accurate recording device paired witha low-quality microphone will not be able to record anything better thanwhat the microphone is capable of picking up. It means that a great



microphone and audio mixer paired with a substandard recording devicewill only be able to record to the limitations of the device's recordingcircuit. While it is not practical for most DV users to acquire and use thebest quality location sound equipment made, it should be the goal of everyuser to acquire and use components that match each other in features andquality. Don't buy the best mixer you can afford and then skimp on cablesand connectors. Don't buy the best shotgun microphone on the market andthen skip using a mixer because you spent your entire budget on themicrophone. You get the idea. We'll discuss rental versus buying later inthe article but needless to say, buying one or two high quality pieces andthen renting the rest as needed is a viable option. [Top]

The First Link - Sound Itself

It is not possible to try to give even the basic principles of sound withinthe confines of this article but let's talk about some basic concepts of whatsound is and why sound behaves the way it does. At the most basic level,sound can be described as waves moving through air. The farther apartthese sound waves are, the lower the frequencies. The closer the soundwaves are to each other, the higher the frequency. In the most basicterms, sound is "messy". It bounces, reflects and behaves in ways thatseem mysterious to most us. It cannot be seen and all of us perceivesound differently. There is an entire branch of study and academia called"Psychoacoustics" which is the study of how humans perceive, process andreact to sound. Sound is definitely a case of "perception being reality."

Sound waves cannot be seen in most cases, buteffects of sound waves are evident if you knowwhere to look. Although not actual sound waves,the ripples produced when a rock is dropped intowater produce a nice visual approximation of what sound waves wouldlook like if they were visible to us.

If you place something lightweight, like a piece of paper infront of a typical transducer, like a two way audio speaker (atwo way speaker has only a woofer for generating lowfrequency sounds and a tweeter for reproducing highfrequency sounds), you will probably see the paper physicallymove if placed in front of the woofer while the speaker

outputs sound at a decent volume level. However, if you place the paper infront of the tweeter only, you will probably see either very little or noperceptible movement. This is because the high frequencies generated bythe tweeter are much closer together and occur at much more rapidintervals. Too rapidly to perceptibly affect the mass of even something aslightweight as the paper unless the amplitude of the sound is increased tovery high levels. Understanding this concept is central to understandinghow sound waves behave.

Low frequency sound waves (basssounds), because of their larger physical



size, tend to interact with theirsurrounding environment in much moreperceptible ways than high frequencysound waves (treble sounds) seem to.All sound waves reflect off of physicalobjects but because of their larger size,lower frequency sound waves reflect andpenetrate objects more than higherfrequency sound waves do. If you can grasp this idea, you will begin tohave an understanding of how to help modify or eliminate undesirablesounds when you shoot in any location. If your apartment or hotelneighbor is cranking his stereo loudly in the room next door, whichfrequencies are you hearing through the walls? Obviously, the higherfrequency sound waves do not have the strength to penetrate the wall.Few of the mid range sound waves will penetrate the wall. What you willmostly hear through the wall are mostly the low frequency sound waves.

"Preventative Maintenance" What we deem as "poor quality" sound can be manipulated and adjustedall along the audio path in different ways but in most cases, it is best toadjust and compensate for the "poor quality" sound before it ever entersthe audio path. Although this sounds like a simple concept, the reality isthat it is much more common for people to hear what will obviously be asound problem (undesired noise, excess ambient sound, technical soundproblems like hum or buzzes, etc.) and to just go ahead and shoot, ratherthan determining the source of the undesirable sound and fixing it. Insome cases, it's just sheer laziness. It's a pain to hunt down an audioproblem and fix it before rolling. When shooting with a crew or in limitedaccess or time-constrained situations, this is somewhat understandable butyou should know that despite all of the great postproduction technologyavailable, basically, what you hear is what you get. If you record poorquality sound, it will always be poor quality, no matter what types offilters, plug-ins or processes you run it through. It pays to spend a fewextra minutes to fix audio problems before you shoot.

Below are the top five most common causes of location sound audioproblems that most people will run into when shooting. You will notice thatseveral of the categories kind of overlap each other in definition. Such isthe nature of sound. Included are some suggestions for mitigating,reducing or correcting the problems before you shoot:

Excessive ambient noise. Too much background noise. Too much traffic noise. People speaking ormaking noise in the background or in the room next door. Dogs barking inthe background. Sirens in the background. Aircraft flying overhead.



Possible solutions. Excessive ambient noise is one of the toughest issues to work withbecause often, the excess ambient sound is beyond your control. Thesolution can be as simple as repositioning your microphones or waitinguntil the excess ambient sound dies down or goes away to more elaboratesteps such as soundproofing a location. Obviously shutting doors andwindows can help when shooting interiors. Exteriors are tougher. In thepast, I have resorted to "paying off" a tree trimming crew using chainsawsto take a "long" lunch or knock off early. In that instance, I paid to recordbetter sound. You must be creative in your thinking and do whatever iswithin your power to limit ambient noise when shooting. Microphonechoice is extremely important here as well. More on that later.

Building noise. HVAC (heating, vacuum and air conditioning) noise. Building creaking orsettling. Elevator noise. Clocks ticking. Doors opening and slamming. Noisylighting fixtures.

Possible solutions. HVAC can be tricky to deal with. If you have done your homework, whenscouting a location to shoot, you should always determine where theaccess is for the HVAC controls for the areas you'll be shooting in.Unfortunately, many newer buildings have "zone climate" HVAC systemswhere there is one control for an entire area or even a floor of a building.So if you turn off the HVAC system to shoot, you may be fine in the roomor area you are shooting in but people in other areas may be dying of heator freezing to death. If you cannot obtain access to HVAC controls orpersonnel to control the HVAC system, you can also reduce the "whoosh"of vents by bringing sound blankets or foam and temporarily blocking asingle HVAC vent. Blocking one or two vents at a time is rarely an issuefor an HVAC system. We typically chill down a room to just above "teethchattering" point before beginning an interview, and then turn the airconditioning off to get rid of the low HVAC system rumble. Video lights andshutting all of the doors and windows will typically heat the room rightback up fairly rapidly. The added benefit is that shooting in a cool roomwill also keep everyone alert and awake.

As far as creaking and settling of a building, there is not much you can do



other than listen carefully as you shoot and shoot alternate takes. You cando the same with elevator noise.

Carefully worded signs (quiet please - video crew shooting) on the doorscan be of help or stationing a crew person at the offending adjacent doorto act as a "doorman", carefully and quietly opening and closing the doorcan help.

Typically, the noisiest lighting fixtures are fluorescentlight banks. As the ballasts age, they typicallybecome more and more noisy. The obvious solution,if you are lighting the scene is to just turn theoffending lights off. Many newer buildings havemotion sensor light switches though and taping blackgaffer tape over the light's sensor can take forever for the light to turn off.Always bring a stepladder and if necessary, you can just remove one tubeand the bank or at least part of it will go out. As in HVAC systems, inmany newer buildings, you may encounter a single set of lighting controlswitches that control all lighting in a large area or even an entire floor of abuilding. Learn how to quickly and safely remove fluorescent tubes fromfixtures. Many times, it's the quickest, easiest option.

Machinery. Fan/hard drive noise from computers. Carrier tone from computer andvideo monitors. Refrigerator/freezer noise.

Possible solutions. Beware of computers. The obvious solution is to turn the CPU off, ifpossible. When it is not possible, another solution is to isolate the CPUwithin it's own nest of sound blankets (a.k.a. known as furniture pads).Make sure to leave room around the CPU so that its fan system still hasaccess to adequate airflow. We typically use two or three C stands withsound blankets grip clipped to the extension arms.

Beware of the "carrier" tone, the high-pitched whine that all CRT's emitwhen turned on. It varies from monitor to monitor but if it is loud enoughand at the correct frequency, it can be recorded and can be difficult to EQout.

Refrigerators are commonly encountered in many locations. They can betricky to hear because as the unit's compressor cycles on and off, you mayhear the sound and not know what it is, then as you look around, theunit's compressor, may cycle off. It's not usually a good idea to unplug arefrigerator, unless you obtain permission from its owner. We usually willclose doors and or isolate the refrigerator using sound blankets ands Cstands. If you do unplug a refrigerator, it's a good idea to place your carkeys inside so that it's impossible to leave without remembering to plug itback in.

Talent & Crew Noise.



Talent/crew fidgeting or moving. Creaking floorboards. Squeaks fromshoes. Clothing rustling/rubbing. Microphone (usually lavalieres) rubbing onskin or clothing. Stomach rumbles. Heavy breathing. Mouth sounds(clicking or sticky mouth)

Possible solutions. Make sure that your talent and crew holds still and breathes softly duringtakes. This can be tough during long takes and having an assistantdirector on the crew can really help enforce this. Most crews are fairlysavvy about this but at times, observers, crowds and even clients cancause a lot of off-set noise that can be a nightmare to deal with in post sodeal with it before you roll.

Creaking floorboards can be challenging. If the talent's feet are not seen inshot, carpet or "dance floor", a portable type of flooring system can be laiddown for crew and talent. Squeaking shoes can be remedied by removingthem if they are out of frame, using baby powder or even a lubricant likeWD-40 or silicon spray although these can stain shoes. Shoes squeakingon floors can be tougher to deal with than squeaking shoes themselves. Abit of sawdust or even once again, removing the offending shoes can helpalthough it's a little strange to see a crew and talent doing scenes in theirsocks. I've done it though and it can lighten the mood although it'sprobably not the safest way to shoot a scene. Grip equipment can beheavy and dangerous.

Clothing rustling and rubbing are also one of the most common challenges.A lot of this can be mitigated I the correct types of clothing are used. The"sound mixer's nightmares" are silk, rayon and corduroy. Trying to mic afemale talent wearing a silk blouse will test the patience of even the mostexperienced sound person. The other half of this equation is just learningbasic mic techniques. There are many different "tricks of the trade" when itcomes to learning how to put a mic on talent and no having it rub andpickup extraneous noise. More on this later in the article.

Mouth sounds are more of a problem when doing voiceovers but can be aproblem on set as well. Water helps. Always make sure that all talent haseasy access to water as they shoot scenes. Depending on the person,water alone may not remedy "sticky" mouth. One of the best solutions forsticky mouth is, believe it or not, green (Granny Smith) apple slices. Theacidity and sugar content balance of this particular variety tends tostabilize the saliva and make it so that mouth clicking and smacking isreduced or eliminated. I work with several VO talents who have been usingthis method for years and swear by it. It works.

Sound/Video Gear. Ground loop hum/buzz. Loose or defective connector/cable crackle. "Hits"



when using wireless microphones. Camera motor noise. Video monitorcarrier tone. Substandard microphone mounting/handling. Wind buffeting.

Possible solutions. Ground loops are perhaps the most common equipment problem as far aslocation sound. Many of these issues occur because professional balancedgear is interfaced with consumer-unbalanced gear. Using the proper gearwill remedy most ground loop issues. In general, using Radio Shack styleadaptor plugs and jury-rigged cable adaptor plug combinations are a recipefor hum or buzzes. Always use professional balanced XLR gear as much aspossible. More on this in the equipment segments later in this article.

Cables are easy. If you experience bad or loose connectors or cables, markthem with a piece of tape and either repair them, if you are talented withsoldering cables and connections or replace them.

Wireless microphones are susceptible to noise.From the very cheapest consumer models to thetop of the line pro units that sell for $4,000.00to $7,000.00 per system, all wireless systemscan experience interference. The more expensivethe unit, generally, the less susceptible toextraneous noise, plus the higher the soundquality. Only use wireless when you must. Donot shoot sit down interviews with wirelesssystems because you are too lazy to run a cable on the floor. With theadvent of new high-end digital wireless systems, noise is becoming less ofan issue than with analog units. Eventually, all wireless systems willprobably be digital and we'll be free to use them anywhere we want forthe most part.

Camera motor noise is almost always a by-product of using an on-cameramicrophone. It's really simple to fix this one. Don't use an on cameramicrophone unless it's ONLY for ambient sound. NEVER try to record talentwith an on-camera microphone; it's the perfect recipe for bad sound. Theon-camera microphone will pickup very little of the talent's sound and lotsof background ambient sound. If you must use an on-camera mic, buy ahigh quality microphone mounting system and you should eliminate mostcamera motor noise.

Video monitor carrier tone can be picked up if it occurs near themicrophone. Move the monitor or turn it off.

Microphone mounting or handling. Booming technique is an acquired skill.You don't just buy a boom and start using it successfully. It takes trainingand practice to become a good boom operator. As far as the microphonemount itself, beware of using cheap, rubber band mounted microphonemounts. These are simple metallic ring systems where the microphone issuspended in the ring using rubber bands. These types of mounts are okayfor stationary use but for hand booming, many of these mounts areinadequate. A high quality microphone mount can take a lot of handlingand not transmit it to the mic element.



Wind buffeting can be very tough to prevent when shooting outdoors. Theeasiest solution is to use a quality microphone mounting system, zeppelinand windsock. More details on these later.

Four points to remember about the "first link" in the audio chainand "preventative maintenance"

1 . The audio chain is only as strong as it's weakest link

2 . Low frequency sounds, because of their larger physical size,tend to interact with their surrounding environment in moreperceptible ways than high frequency sounds seem to.

3 . Fix as many sound "issues" as possible BEFORE shooting

4 . If you record poor quality sound, it will ALWAYS be poorquality

[Top]

The Second Link - Microphones

In our discussion of sound, we talked aboutsome basic concepts of what sound is (andsound waves) and a few basic characteristics ofhow sound waves behave, (they are 'messy',the differences between how low frequenciesbehave versus high frequencies). Microphonesare, at their most basic, transducers that that convert input energy of oneform into output energy of another. Microphones are broken down into twoseparate categories; Dynamic and Condenser. Most Dynamic microphonesare the moving coil type. Moving coil microphones use a magnet, a coilwrapped with wire and a diaphragm that sits over the top of both. Soundpressure hits the diaphragm and moves the coil across the magnet. Thiscreates the voltage that travels out and along the mic cable on the way tothe mic preamp. With Condenser microphones, Phantom power from abattery inside the mic, or from mic cable from the mixer or recordingdevice, or a separate power device is used to power the microphone. Thephantom power charges a capacitor. This capacitor holds a charge in themicrophone's fixed backplate. In front of the backplate, a thin diaphragm islocated. When the diaphragm moves in relation to the fixed backplate, acharge is created in proportion to how much movement the diaphragmmakes. Unlike the signal created by the dynamic mic, a condenser's signalis very weak and must be amplified before it gets to the mixer orrecording device. Condenser microphones contain a small amplifier thatboosts the signal before it leaves the mic

It may help you to visualize what is happening inside the microphone byimagining how a speaker works. A microphone works the exact same waythat a speaker works, only in reverse. When a speaker receives anelectronic signal, it moves its transducer in response to the amplitude andmodulation of the signal that it is receiving from the amplifier. When a



microphone element is moved by the sound waves, it generates the samekind of electronic signal. The main difference is that the microphoneSENDS the signal out to a monitoring or recording device, whereas thespeaker RECEIVES a signal from an amplifier.

Balanced versus Unbalanced What do the terms "balanced" and "unbalanced" mean? Without going intoa lengthy explanation of impedance and electronic signal measurement,balanced line-level equipment operates at a much higher nominal level(+4dB). Besides a positive and negative lead, it also uses a third groundedlead (or 'earthed' lead as our UK friends say), and usually, but not always,uses three-pin, locking XLR connections. Unbalanced line-level equipmentoperates at a lower nominal level (-10dB) and has only a positive and aground lead (no negative) and mostly uses non-locking RCA connections,although unbalanced connections are also occasionally 3.5 mm mini plugs,1/4" (tip-ring TR) plugs and spade lugs.

Balanced XLR

Unbalanced 3.5 mmmini-plug

Balanced 1/4" or unbalancedstereo1/4"

Unbalanced RCA

The basic difference between balanced and unbalanced microphones,connectors and devices are that professional audio and video equipmentpredominantly uses balanced cables and connections. Consumer equipmentalmost exclusively uses unbalanced connections. Why should you care?Improperly wiring to unbalanced equipment is probably the single mostcommon cause for ground loop problems, interference, hum and buzz. Isuggest you use balanced professional equipment whenever and whereverin your audio chain that you can. Balanced equipment is much lesssusceptible to interference, but can still pick up ground loop humsespecially if there are grounding problems in the electrical system theequipment is plugged into. However, you will still have fewer problemswith interference in your audio if you use balanced equipment. Almost allprofessional microphones and mixers operate using balanced connectionsfor this reason.

Microphone types and purposes Although there are probably more than a dozendifferent microphone types, it probably makes sense todiscuss the most common types of microphones usedin film and video production. Just as a golfer uses aspecific type of club to "tame" specific areas of the golfcourse, a discerning location sound mixer might useseveral types of microphones during the typicallyvaried shooting situations encountered in a typicalproject. Let's discuss the various microphone types



that are used in 90% of shooting situations, Shotgun/hyper cardioid,cardioid microphones and lavaliere microphones. Besides physicalconstruction and size, the main factors that categorize microphones aretheir pickup patterns and characteristics. Do you recall our discussion ofwhat sound waves look like and how they behave? Certain pickup patternsare better than others for picking up different subjects and specificportions of the audio frequency spectrum. Certain pickup patterns havespecific desired characteristics. Add up these factors and you will see thatthere is not always a "right" or "perfect" microphone for any givensituation. You could give three different cinematographers the samelighting and grip package and each of them will use a different combinationof lights and support gear to realize each of their individual interpretationsof how the scene should look and feel. You could give three differentlocation sound mixers a sound kit and each of them might possibly use adifferent combination of microphones and techniques to shoot a scene. Itshould be apparent to you by now that there is no such thing as a "generaluse" microphone. This should also prepare you for the fact that you willneed to eventually rent or own multiple microphones.

Shotgun/Hyper Cardioid & Cardioid Microphones

These are pickup patterns for three types of cardioid microphones.

Notice how even the narrowest pickup pattern (hyper cardioid) still picks up sounds fromthe rear axis.

Some of the terminology in classifying microphones can become confusing.The term "shotgun" describes a type of microphone that is a long narrowtube, not unlike the barrel of a shotgun, hence the term. You will hearterms described below like "long shotgun" and "short shotgun". In simpleterms, a longer shotgun usually has a narrower angle of acceptance ofsound and rejects more sound from the sides, also referred to as "off-axis". Shorter shotguns will usually pickup more sound from the sides andwill not isolate a single element as much as a longer shotgun will. Theterm "shotgun" is sort of slang for any long, narrow tubed microphone.The official terms are variants of the term "cardioid" If you refer to theabove illustration, you can see the differences between cardioids, hypercardioids and super cardioids. These types of microphones are used inabout 90% of sound for picture recording. What this means for us is thatthese kinds of microphones can be aimed at talent as they record dialogueand somewhat isolate the talents sound from most of the extraneousbackground sound. A shotgun or cardioid mic is almost exclusivelyoperated mounted to a microphone boom so that it can be usuallysuspended about two to three feet above the talent, depending on framing.



A common misconception is that a shotgun microphone has a longer"reach" than other microphones, as if it can "magically" record sounds thatoriginate a considerable distance from the microphone element. This is thewrong way to think about how microphones and sound behave. Longermicrophones don't have any "reach"; they have a narrower angle ofacceptance than other microphones. Even the longest shotgun microphonewill pick up lots of extraneous ambient sound in the right situation.Remember that sound is "messy"? This means that the undesirable soundis reflecting and bouncing into the area where you are trying to recordclean sound mixed with just a slight amount of ambient sound. In order tounderstand the reason that overhead booming is used whenever possible,think about what lies beyond the talent. If the mic is pointed at the talentat mouth level from near the camera, not only will the microphone pickupthe talent, the microphone will also pickup whatever is behind the talent.By pointing the microphone element down toward the talent from above, itpicks up the voices of the talent and mainly, the floor or ground as thecase may be, rather than all of the sound of the activity behind the talent.Shotgun microphones are more directional than other types ofmicrophones. Hyper cardioid and cardioid microphones have a slightlywider angle of acceptance than shotguns but narrower than most othermicrophone types. Some seem to prefer the more open sound of a cardioidor hyper cardioid instead a shotgun, but it can be difficult to get enoughisolation on talent when using a cardioid, especially when shootingexteriors. In my experience, the single most typical problem encounteredwhen shooting on location is excessive ambient sound creeping into therecording.

Above all other factors, the distance between the mic and the soundsource will have the largest influence on the overall sound in yourrecordings. Regardless of pickup pattern, cost or quality of your mic, if it isplaced too far away or aimed improperly, then your sound quality will bediminished.

Which shotgun/cardioid microphone should I buy? I wrote a review of inexpensive shotgun microphones that is also postedon this website so if you are in search of a good, low cost shotgunmicrophone, I suggest you read this article. In the interest of not addingall of the copy of that review to this article, here is the link to the reviewLow Cost Shotgun Microphone Comparison In a nutshell, plan on spendingfrom $250.00 to $450.00 for a low cost shotgun microphone.

If you are interested in a higher quality shotgun, hyper cardioid or cardioidmic, I will list a few of my favorites but just realize that these are by no

http://www.kenstone.net/fcp_homepage/review_shotgun_mics.html



means the only good microphones of this these types available. Probablythe most common shotgun microphones used in sound for pictureproduction are the Sennheiser MKH series. The Sennheiser MKH-416($999.95 street) is an industry standard short shotgun and for goodreason. It is very flexible, reliable, simple and efficient. This MKH-416 wasslated to be replaced totally by the newer MKH-60 ($1,299.00 street)years ago but the continuing demand for the MKH-416 has been such thatSennhesier has continued manufacturing and selling both models for years.The MKH-60 is a more modern, sophisticated take on the MKH-416 andboth are excellent short shotgun microphones. Two other favorites of mineare the Neumann KMR-81i ($1,199.00 street) and the Sanken CS-3($1,499.00 street). The Neumann line of microphones are world renownedfor their superb German construction quality and sound and KMR-81i is abeautiful sounding example. The Sanken CS-3e was developed inconjunction with NHK, Japan's largest broadcaster and has fast becomevery common on film and television sets all over the world. It is anexcellent sounding microphone.

Sennheiser MKH-416 ($999.95

street)

MKH-60 ($1,299.00 street)

Neumann KMR-81i ($1,199.00street)

Sanken CS-3 ($1,499.00 street)

As far as long shotguns, The Sennheiser MKH-70 ($1,399.00 street) is agreat workhorse long shotgun that I find very useful for exterior interviewsand dialogue as it's narrow angle of acceptance reduces exterior ambientto a low level. It is also quite rugged and reliable. The Neumann KMR-82i($1,599.00 street) is basically a longer version of the KMR-81i and alsofeatures that smooth sound quality that all Neumann microphones areknown for.

Sennheiser MKH-70 ($1,399.00

street)

Neumann KMR-82i ($1,599.00street)



There are also numerous other shotgun, hyper cardioid and cardioidmicrophones available from Schoeps, AKG, AudioTechnica, Beyer Dynamic,ElectroVoice and others that are great microphones. As we discussedearlier, plan on using, renting or owning several different microphones.There are no absolutes when it comes to microphones; it's just that certainbrands may offer a sound quality that is more appealing or more effectivein various situations. Certain brands and models may be more rugged orhave a more delicate sound but also a delicate construction. I personallyown eleven microphones and will probably acquire more of them in thefuture. Each is a unique tool that is better suited to certain situations,budgets and uses. The bottom line here is to rent, borrow, demo andlisten before you buy. Certain microphones will be better for yoursituation.

What Else Do I Need to Use Shotguns/Hyper Cardioids andCardioids? If you are serious about recording high quality sound, you soon realizehow futile mounting a microphone on a camera is. The time will comewhen you will finally decide to get serious and go with a microphonemount, zeppelin, windsock and boom pole. You should remember that allof these tools that are necessary to work in conjunction with shotguns,hyper cardioids and cardioids, in total, may cost as much or more than themicrophone itself. Allocating your budget intelligently here comes into playonce again. It would make much less sense to buy a top of the lineNeumann shotgun, then skimp by purchasing a rubber band mount onlyand not purchasing a zeppelin, windsock and real boom pole. Buy a morereasonably priced microphone and all of the support gear needed to use itcorrectly. You should budget for purchasing all of these items at once.Let's break down all of these support items, one at a time:

Microphone Mounts As we discussed earlier in this article, there are many different models of"rubber band" mounts. Even if you are on a tight budget, this is not aplace to try to skimp. If all of your sync sound shooting is stationaryinterviews, you may be able to get away with using a rubber band mount,but if you are planning on doing any "walk & talks" you must invest in amore sophisticated mounting system. Both Lightwave Systems and Rycotemake excellent microphone mounting systems. The mount that we usethat I am quite familiar with is the Universal Mini Mount from LightwaveSystems. The reason we like this mount so much is because it is extremelyeffective, it is very versatile and it is well engineered. The beauty of theUniversal is that with the proper adaptors, the same mount can be used ona boom pole, on a camera or mounted on a handgrip for sound gathering.You will want to budget approximately $200.00 for a microphone mountingsystem if you want to obtain top quality results.



"rubber band"

Universal Mini MountLightwave Systems

Zeppelins and Windsocks A Zeppelin is a protective enclosure that totally encapsulates amicrophone. The name evolved from the microphone Zeppelin's obviousresemblance to the German gas dirigibles of the 1920's and 30's or fromtheir less obvious resemblance to the seminal band Led Zeppelin. The juryis still out on that point. The function of the zeppelin is to not only protectthe somewhat delicate microphone element but also to filter outextraneous wind and HVAC air movement. The ideal situation is to haveseparate sizes of Zeppelin for both long shotguns and shorter shotgunsand cardioids although in practice, we have been satisfied in using shortershotguns in our longer size Zeppelin.

Zeppelin

Burning Zeppelin

Led Zeppelin

Windsocks (dead kitties or road kill due to their usual gray or black furappearance) are synthetic fur-covered sleeves that are designed to slip onover a Zeppelin. Most offer Velcro tabs and or zippers to snugly fit aZeppelin. Windsocks offer a much higher degree of wind resistance thanjust using a Zeppelin alone. Some of the manufacturers even offer twodifferent length of fur on their windsocks, a shorter hair for moderate windand a longer hair for strong wind. Besides diminishing wind noise andbuffeting, using a furry wind sock will cut out some of your high frequencyresponse so you should not use one all of the time, you need to listen towhat the microphone is picking up and choose to use or not use awindsock in addition to the Zeppelin accordingly. There are also socks thatare "velvety" instead of furry and work very well in winds up to 15 mphand give minimal high-frequency attenuation.



Windsock

Another alternative to a fully encapsulated Zeppelin are the slip-onwindscreen systems. Lightwave refers to their system as "The Equalizer"and Rycote refers to their system as a "Softie Windjammer". Theadvantage to these systems over using a full Zeppelin is that they are bothless expensive and are smaller and quicker to use. This can be handy formore "run & gun" ENG (electronic news gathering) style shooting. Thedisadvantage of the slip on windscreens is that they do not provide thesame amount of isolation and wind buffeting protection since by design;they only cover the front portion of the microphone element. We usuallyuse the slip-on Equalizer when traveling, when space is at a premium orwhen shooting indoors. When shooting outdoors though, you will obtainbetter sound using a full Zeppelin and windsock. You should also know thatyou might sometimes need to use windsocks indoors, particularly whenyou cannot turn off HVAC systems or in when shooting large auditoriums.

"The Equalizer"

"Softie Windjammer"

Boom Poles Now that you have at least one good shotgun, hyper cardioid or cardioidmicrophone and a microphone mount, zeppelin, windsock or a slip onwindscreen, how do you use it? The first step is to obtain a boom pole.Boom poles are available in a variety of lengths, styles and materials withthe most popular poles being made of aluminum and carbon fiber.Generally, it would be better to own two lengths of boom pole, a short onefor travel and small setups and a longer one for larger wide shots. We ownone boom pole, A Gitzo G1553 carbon fiber model that can extend toabout 11'. This unit was very reasonably priced (for a carbon fiber model)at about $330.00 street. Aluminum boom poles are generally heavier thancarbon fiber but are cheaper and easier to repair. I have seen decentquality 9' aluminum poles start at around $150.00. If you shoot morenarrative style projects, it may be worth it to spend the extra money for alighter carbon fiber model.



Aluminum

Carbon fiber

You will notice that as you begin to look at boom poles, there are a lot ofdifferent models on the market. The other decision for you to makebesides material construction and length is whether or not you want topay for an internally cabled model or not. Internal cabling is much handierand a LOT more expensive. The K-Tek version of our Gitzo with a coiledinternal cable system runs almost three times as expensive in price thanas our Gitzo. We live without an internally cabled pole and it's fine. We domostly stationary booming setups with an occasional hand boomed shot. Ifwe did more narrative or ENG/reality type work that was largely handboomed, I would spend the extra money for a cabled pole. When you aredoing a lot of different setups, hand booming a lot or when you travel, acabled pole is more convenient. You just have to decide if the extra moneyis worth it to you.

Lavaliere Microphones A lavaliere is defined as "a pendant worn on a chainaround the neck" which should give you a good ideaabout what a lavaliere microphone ('lav' for short) is. Inthe early days of broadcasting, the smaller microphoneswere actually worn around the neck in the samemanner as a necklace. You may not realize that today'slavaliere microphone is an incredible feat ofengineering. The most popular lavaliere microphones

today are incredibly small. Smaller than a match head. So small that theycan easily be hidden in the talent's hair of even behind a tiny button on ashirt. Lavaliere microphones come in usually one of two flavors, omni-directional and uni-directional, although unidirectional lavalieres are rareand are limited mostly to newscaster style applications. An omni directionalunit has a pickup pattern that picks up fairly well from all sides. Aunidirectional lavaliere has a pickup pattern much more like that of ashotgun or hyper cardioid microphone; it must be "aimed" at the talent'smouth. Because a unidirectional microphone must be aimed at the talent'smouth, the opportunities for hiding the microphone element are mostlyeliminated, limiting the use to mostly planting the microphone in the centerof the talent's chest. Besides being used on talent, certain lavalieremicrophones are also handy for using as a "plant" microphone. A "plant"microphone is typically placed in a hidden spot on the set to pickup talentas a supplement to or instead of a boom microphone. So if you see a"roundtable" or "dinner table" setup, the sound mixer may be covering thescene with one or more "plant" microphones hidden in the centerpiece onthe table. Plant microphones can also come into play when scenes are shot



with a Steadicam or large dolly moves where it may be impractical to havethe boom operator try to follow the camera. Another instance could be thatwardrobe restrictions make using body mounted lavalieres tough orimpractical.

These Are a Few of My Favorite Lavs

The Tram TR-50B ($250.00-$300.00 street) hasbeen a workhorse industry standard for manyyears. It was the first lavaliere microphone touse a "vampire" clip mount (a small plastic clipthat holds the microphone and has two small

'needle-like' barbs) and it sounds very neutral. The Tram is available inseveral different configurations and a frequency-modified version is sold asa Sonotrim ($350.00 street). Another similar mic with a slightly differentsound but a similar look and construction is the PSC MilliMic ($300.00street). All three of these microphones share the same basic rectangularform factor and all Sonotrim and PSC seem to be variants of the basic TR-50B design.

For a completely different approach, the Countryman B6($350.00 street) is the smallest lav in the world. Youmust hold one in your hand to comprehend exactly howsmall this microphone is. The really cool part is thatbesides being the smallest, it is also, in my opinion, oneof the nicest sounding as well as one of the most flexibledesigns. This mic is so miniscule, that it can be easilyused as a hair or wardrobe microphone. The microphone is also availablewith small plastic caps that can alter the basic frequency characteristics incase a different response is desired or if the microphone's response frombeing buried under wardrobe is too muffled. Very cool! The microphone isalso sweat-proof and waterproof so if the talent will be in scenes withwater or rain (the mic element itself is waterproof, not the power supplyalthough it could be made waterproof with the addition of gaffer tape andsilicon sealant) or if the talent will be sweating a lot. The Countryman B6is also available in different flesh tones as well as black and white.

The Sanken COS-11 ($400.00 street) is anotherpopular lavaliere that is slightly larger than theCountryman B6. The Sanken offers what some peoplefeel is a slightly smoother response than theCountryman B6 at the sacrifice of a slightly largerphysical size. The Sanken is also waterproof andavailable in flesh tone as well as black and gray. TheSanken is another marvel of engineering and is

considered a premium, top of the line lavaliere.

Wireless Microphone Systems There are also two methods that lavalieres aretypically used with in production, wired orwireless. While wireless transmitters can also



be used with a handheld microphone, they aremost commonly teamed with lavalieremicrophone elements. Some sound mixers alsouse wireless systems on their boom mic (thisis very typical in reality type 'run & gun' styleshows like 'COPS') Also, some location soundmixers use wireless systems to "cut the tether" from the sound mixer tothe camera although this strategy can be risky unless the camera operatoris always monitoring the camera's audio. In general, use cables wheneveryou can although for certain shooting styles and locations, wireless mustbe used. A wireless system consists of a single transmitter and a singlereceiver. For some strange reason (costs?), many new DV users seem tothink that a single receiver can simultaneously receive the output signalsof more than one transmitter. I have been asked several times if a singlereceiver can work three or four transmitters. The reverse is actually true,more than one receiver CAN receive the output of a single transmittersimultaneously. So in multi-camera shoots, it is possible to have a singletransmitter's output go to multiple receivers on multiple cameras.

Wireless systems are improving but the bandwidththat wireless systems operate on is becoming moreand more crowded. Diversity (dual) antennasystems are considered far superior to singleantenna systems because in a diversity system,when the reception between transmitter andreceiver is weak or encounters interference on oneantenna, the system can switch over to the otherantenna. The UHF (ultra high frequency) band is

generally considered more effective and less crowded than the VHF (veryhigh frequency band). There are brand new digital systems hitting themarket that have great potential to make wireless usage more reliablethan it ever has been. Unfortunately, the first digital systems available areon the pricey side for DV users, costing considerably more than most high-end camcorders. That's the bad news. The good news is that the digitaltechnology will trickle down the price scale just as it did with digitalcamcorders. In few years, probably almost all wireless systems will bedigital. When that occurs, wireless microphone system usage willundoubtedly skyrocket, as wireless systems are so much more convenientto use than dealing with long runs of cable. But until we are all usingdigital wireless systems, my advice is to only use wireless when you must.

Another term to look for is "frequency agile". If your wireless system is"frequency agile", it means that when your system encounters other users,static or interference, it can be switched over to another operatingfrequency. I am amazed that all wireless systems DON'T have this feature,but they don't.

What Are The "Hot" Wireless Systems For DV Users?



I will admit to being quite biased when itcomes to wireless microphone systems. Ihave rented and used numerous wirelesssystems during my career and in myopinion, Lectrosonics, hands down, are thebest values in wireless systems. There aresystems available that perform as well as

the Lectrosonics UHF systems, but the problem is that they cost a lot ofmoney. $4,000.00 to $7,000.00 per system. The Lectrosonics 210 systems($2,800.00 to $4,000.00 street) are another industry standard thatdeserves their excellent reputation. This system is probably used on morethan half of all of the feature films and television shows made.Lectrosonics' product is built incredibly well and performs reliably. No, Idon't work for Lectrosonics, have never received and compensation fromthem. I just love their product.

If you cannot afford a Lectrosonics 210 UHF system, you can check outsome of their lower cost systems, but not all of them are frequency agile.

The Sennheiser Evolution 500 series ($600.00 to$1,000.00 street depending on options) is another viable,low-cost option for a wireless system. This system isavailable with several different options and performsreasonably well, especially considering it's cost.

When using wireless systems, consider renting over purchasing. This isanother situation where you probably will not need wireless systems all ofthe time so it probably makes more sense for the average DV user to rentthe best rather than buy something "middle of the road". When usingwireless systems, it is essential that you feed the system brand newbatteries quite often. Wireless systems eat a lot of batteries and begin toperform poorly as the batteries get weaker. If using wireless all day duringa typical 10-hour day, plan on at least one and possibly two batterychanges.

Other Microphone Types Although a shotgun and a lavaliere are the standard productionmicrophones, there are certain instances when you will want to considerusing or supplementing your audio kit with other types of microphones.

Dynamic Shotguns, hyper cardioids, cardioids and lavalieresare usually condenser microphones. This meansthat they each require internal or external powersources to amplify the signal that they output. Theymust have an internal battery or require phantompower. Phantom power is supplied to the

microphone via the XLR connector from the XLR outputs of recordingdevices or mixers. Phantom power is typically rated at 48 volts,abbreviated as 48V, although some microphones require less voltage. Whyall of this discussion about condensers and power? Because a dynamic mic



DOESN'T require any power, hence it is more reliable. Anothercharacteristic of dynamic microphones is that dynamic microphones cangenerally record at much higher sound levels than condensers withoutdistorting. When we discuss a dynamic mic, we are talking about suchvenerable "institutions" like the Shure SM-57 ($100.00 street) (thestandard rock singer stage microphone) and the Electro Voice RE-50($165.00 street) (the standard newscaster location microphone). Thedownside is that dynamics are not very sensitive so they really only pickupsounds that are very close to the diaphragm. Unless you want to have themicrophone in your shots, the dynamic microphone is not very useful inmost production situations. When you are shooting something that issupposed to look "newsy", the hand held dynamic microphone is the"weapon of choice". Other than this application or recording live, highvolume music or sound effects, its use is severely limited in normal videoor film production.

Shure SM-57 ($100.00 street)

ElectroVoice RE-50 ($165.00

street)

Boundary Boundary microphones (PZM - PressureZone Microphones) are usually flat or plateshaped microphones that are set on a tableor fastened to a wall. These microphonesare useful for recording roundtables oraudience reactions with certain caveats.These types of microphones use the

surface that they are fastened to pickup sounds. When used on a tablewith talent, these microphones will pickup finger tapping, pencil rolling,cups being picked up and set down and any other physical sounds thatreflect off of the surface they are fastened to. Boundary microphones arealso effectively used to mic large areas of audience and work well forpicking up laughter and applause. They are not effective at pickingquestions from the audience.

Stereo

Stereo microphones are more commonly used inrecording musical or dramatic performances than intypical narrative dialogue situations. Dialogue almostalways ends up as a mono element, even in 5.1surround mixes so there does not seem to be muchreason for recording dialogue in stereo since voice is



not a stereo element. Another factor to consider isphase cancellation. Without a decent knowledge of stereo recording andpostproduction processing and mixing, you may encounter phasecancellation where certain sounds within your mix will be cancelled out. Onthe other hand, stereo microphones can work very nicely for recordingambient environments. Any environment sounds more realistic in stereosince stereo recording mimics how our ears perceive our actualenvironments. There are stereo microphones on the market, ranging frominexpensive consumer units that sell for $99.00 to units like the SankenCS-5, a high-end stereo shotgun. In summary, stereo recording is theexception rather than the rule in sound for picture recording. My rule ofthumb for recording in stereo is to determine if stereo recording wouldenhance the subject matter, live musical or dramatic performance, forinstance. In most cases, dialogue would not be enhanced by stereo.

Choir

Choir microphones are designed to be suspended above livechoirs. They are good for picking up a large crowd ofvoices. Although they are good for recording an ensemble ofvoices, they are not nearly directional enough to pickupindividual voices out of a crowd. If you shoot a live event,choir microphones are great for picking up the audience

reaction, although once again, choir microphones cannot pickup individualquestions or statements from an audience very well. There is nomicrophone that will pick up an individual sound well unless themicrophone element is fairly close to the subject.

[Top]

The Third Link - Cables and Adaptors

We have already discussed the differencesbetween unbalanced and balanced connectionsand cables. Cables and adaptors are one of themost underrated yet most important parts of theaudio path. It pays to buy the highest qualitycables and connectors. Canare, Mogami andNeutrik all make excellent connectors and cables. While there are literallydozens of different connections and adaptors used in audio and videoproduction, let's go over the most common ones:

XLR

XLR connections and cables use three leads,positive, negative and ground. The XLRconnection has two components, a maleconnector that looks like this and a femalereceptacle. XLR connectors usually have a

locking pin so that they cannot be accidentally pulled out. XLR cables andconnectors are the standard audio connections in most professional sound



for picture equipment.

1/4" Quarter-inch connections are more common in music gearthan in sound for picture gear although there are populardevices like the Mackie line of audio mixers that arecommonly used in both music and video applications thatuse 1/4" connections. 1/4" connections can be mono or

stereo and can be either balanced or unbalanced. These connections arealso common as headphone output jacks on larger gear.

1/8" mini plug (3.5mm mini plug) These connections (usually unbalanced)are very common on consumercamcorders as headphone output jacksand as microphone input jacks. Thisconnection is fairly fragile since it is so

small and hanging any kind of weight with cables, etc. off of the jack is notrecommended. Plug stress is the most common cause of shorts, groundingproblems or failure.

RCA (cinch connections, phono)

RCA connections are the same as the connections used tohook up your home stereo components. Because RCAconnectors are always unbalanced, they are almostexclusively used on consumer gear although a lot of pro gearfeatures RCA connectors as secondary connectors, to be

used in addition to or instead of XLR connectors.

Impedance Matching As we discussed above, there are many more typesof connections and adaptors to go from any of theabove connectors to any other type of connection,but the four listed above will be the most commonones that you will encounter. Special care should betaken when interfacing balanced with unbalanced

equipment. There are special devices known as "impedance matching"boxes that are very useful for interfacing pro to consumer gear. You willgenerally have a better result when using a powered impedance matchingdevice over a passive one. One of my favorites is the Henry EngineeringMatchbox ($169.00 street). This is a box that can simultaneously convert



balanced XLR connections to unbalanced RCA and unbalanced RCA tobalanced XLR. These are very useful for dubbing setups from professionalDVCAM and Beta SP decks to consumer VHS decks, for example.

Distance Another factor to consider is cable distance. Unbalanced connectionsgenerally are not very good for distances over about twelve feet becauseof the lack of a balanced negative connection; noise also has a tendency tocreep into the signal. The relative nominal signal strength of -10dB doesn'thelp either when it comes to distance. Balanced XLR connections generallyare safe to use for runs of up to around 200 feet. At distances farther than200 feet, even balanced lines can use a boost from a line amplifier torestore the signal's strength. Generally, in a location sound kit, you end upusing mostly 25-foot cables for the lines from the microphones to themixer. It does pay to build up a small kit of various adaptor plugs. Younever know when you may have to take a sound feed from a telephone tothe camera, a CD player to an MD recorder, etc. It pays to be prepared. [Top]

The Fourth Link - Mixing and Routing Devices

The first point I want to make in this part of the article is that mostprofessional productions use an audio mixer. The exceptions are singlecamera shoots where the audio is just being used for reference orbackground ambient. But if you are shooting dialogue, you should be usingan audio mixer. It's really that simple. If you are shooting with a stationarycamera and AC power is accessible, you can get a great result with smalldesktop mixers. Just remember, with a location au

location sound - the basics and beyond

Documents