Solutions in Location Sound Mixing & Recording. TIPS by myself and other sound recordists.
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There is almost or is always a solution to a sound recording problem, when additional audio equipment is available, and the sound person knows the problems cause and is able to apply their prior production experience to a remedy. There can always be another solution to a sound recording or intruding audio problems when back up or additional equipment is brought, and you hire an experience sound man or woman whom can recommend alternate solutions. Even though I’m frequently working in Denver and other Colorado areas, I have worked in other states & counties learning these solutions to problems from applied experience and working with other sound operators of all experience levels, including on feature films.
Research your problem online,
or ask another sound recordist
You can also find a solutions via forums like Creative Cow or other production communities. You can buy the right gear from SoundDevices.com, TrewAudio.com, LocationSound.com – they have people whom are also useful resources for equipment advice. The can also give advice on techniques in location sound mixing & recording, as well provide the gear to do so. Calling the equipment manufacturer is also another solution if you are new to location sound and need to speak with a technical support person over the phone. Sennheiser, Schoeps, Nuemann, Lectrosonics, Sound Devices, Zaxcomm, Tascam, Sony, among others all have technical support staff. If you are newer to location sound mixing & recording calling another veteran sound recordist can also be a quick fix to your problems as well – (720) 299-2084. You can also call or email many resellers of equipment like the one’s listed above and often there are tips & tricks these companies can offer you, or provide you with a supply or piece of equipment or refer you to a technique that will help you. But don’t forget a google search can often help you out with multiple ideas. For instance: google search: “reduce clothing rustle with hidden lavaliere microphone,” is an example.
Removing Buzzing Sounds & Electric Noise
Unshielded or Unbalanced Audio cables
This is usually poor ground or unbalanced audio cables most often, that include most phone cables, RCA cables, 1/8″ or other connections and they are more prone to pick up electromagnetic interference when they exceed 3 feet. XLR connected cables have a ground connection, and also can extend past the limit where signal loss and electric interference causes noise or buzz problems common to other cables. There are cables for RED, ARRI and other specific cameras that have engineered their hardware past these problems. Shielded cables can be interfered with when to close to powerful electric sources or too many electric sources.
Wrong Power, Right Gear
Incorrect power supply to equipment – Examples if you apply phantom power to a dynamic lavaliere, or line based mic, or line level connection. Or applying T power to a non Tonader based microphone, (T-Power), it will cause line hum or buzz, and quite possibly damage the equipment. Applying phantom power to some line level sources may also damage equipment, but there are exceptions. Poorly shielded microphone or connection cables or cables in proximity to electric cables or sources will cause line buzz. Poorly constructed light dimmers near XLR cables will cause line buzz or the 50 or 60 cycle hum in XLR cables or any other cable. Read tips on T Powering here. Read tips on Phantom Power here. It is better as a sound recordist to stop and fix the problem or to retake all needed shots than to continue recording noise into the recording, as this cannot be entirely removed and will ruin the production, and cost to you among the producers, clients & crew for allowing this noise or any other unacceptable noise into the footage that should have been addressed immediately.
Longer cable runs past 25 feet can also cause buzz or weaken the signal, so consider using lavaliere microphones or other radio transmitting sound devices to transfer/transmit your sound to your recording devices.
Too many cables crossed or audio components that are connected or near dirty power sources that are un-shielded will cause these issues as well. Power conditioners, ground lifters can sometimes be used, or going to DC power of your devices (using batteries is a solution as long as the components are sending power correctly to each other), is ofter a solution, as well powering equipment correctly. These problems occur less in ENG or EFP, or mobile recording situations, but can be common if care is not taken.
Reducing Air Conditioning Noise or Wind
WIND: Wind screens are imperative to have on any microphone except in well controlled interview situations. Aside from wind screens that a screen or foam based, there are also fuzzy windscreens for most all types of microphones that can be used as well to reduce wind noise, often nicknamed “fuzzies.” In windy situations outside, blocking the wind with a large stable barrier that does not rustle of flap, can also reduce wind intrusion. For outdoors, hiding lavaliere heads under clothing, and using wind screen or foam protection on the microphone head can also can eliminate wind rustle in sound recorded. For shotgun microphones, using a large zeppelin or dead cat wind jammer can also help outside in moderately windy situations as well. A dead cat is a large furry wind diffuser and a zeppelin is a large blimp like wind diffuser for shotgun microphones. Wind barriers can be made as well to reduce wind from hitting microphones as long as they are not affecting the sound. Most wind diffusing devices are designed to absorb wind, or diffuse it or direct it away from the microphone diaphragm.
AC, White Noise & Related Sounds: Turning off air conditioning or electrical appliances not relevant to the shot or subject matter is the first step to avoid the problem. Choosing another location or using high pass filters on mic connections in air conditioning problem-laden situations is another idea. Shielding air ducts if possible is another solution, or flagging them or blocking them in the location of the shoot or shot. Other solutions include using wind barriers, or barriers to the sources that are causing the problem. As AC is the same as wind in a lesser degree wind barriers and high pass filtering are often solutions for the sound person.
Using a low cut on the mixer with an adjustable rolloff will reduce fan noise, moderate air conditioning, even city traffic noise (off in the distance), as well some other white noise sources. Adding barrel filters / high pass filters will often work, (except with phantom powered sources), and can greatly reduce the problem. PSC High Pass filters are excellent for this task. Using more lavalieres than boom sources for audio can reduce air conditioning noise as well in some instance.
As an audio tech I’ve heard several noises that can be resolved with diplomacy or by other remedy. They include:
- Air Planes, helicopters and aviation: Retake the shot or find another location if heavy air traffic continues to interrupt your location sound recording.
- Power tools, lawn mowers, noisy neighbors: Explain to the people sourcing the noise the problem and ask for a temporary pause with the operator.
- Hallway chatter: have the supervisor inform everyone in the area that loud chatter = equals audio problems. If you are not in the shot, the motto is to be quiet in almost every instance. Hallway signs on doors in corridors can eliminate the problem. Explain to everyone in the vicinity that conversation is to be heard by those directly on camera and loud chatter is intrusive & inconsiderate, in a polite way. Explain that lost time due to distraction or lost recording time equals a loss of money.
- RF Hits – radio signal problems are the common culprit. Your receivers can be getting interference from something on the same radio frequency, or your batteries in transmitters are low, which causes loss of signal, or your transmitters are too far away from you/your receivers will compel you to move you/receivers closer to the transmitters. Radio hits or interference sound is like a radio tuning off of a channel for a description or a static sound.
- Popping crackling noises when you move, cables are moved or when the talent moves – chances are there is a short in a cable; either a mic cable, the lavaliere cable with the mic attached or the the AF out or in/ XLR cable on a lavaliere, or a bad cable to the boom or another bad cable. If there is not a locked connection to the audio input or output, this will occur as well. Old XLR ports or cable connections can also cause this problem where they do not lock the cable in properly. You are hearing a loss of disruption in signal in the damaged cable which has a crackling sharp sounding noise.
- Hollow or Distant Sounding Mics – This can be a microphone head from a lavaliere has fallen into the persons wardrobe, or away from the persons heads. If you have multiple mics it’s best to isolate each one from the other on a separate channel and/or track on the recording. Fading down the microphone sources that are not active or picking up the desired sound is the best practice. This also takes out unwanted dialogue when someone is speaking off camera without necessity or is out of the shot, but still miced up.
Solutions to noise can be anticipated with a location scout by an experienced location scout, or preferably a sound person with equipment including a sound mixer as well as microphones to test the ambient noises, as well survey the probability of other intrusions to the sound recording. Obtaining a film permit in public places, as well secluding the production from the public or intrusive elements is critical in larger scale & budget productions, especially in features. Hiring police as well to control areas or traffic can also move annoying intrusions away from your production or set.
Hiding Lavalieres in Clothing
Cotton is a better material for hiding a lavaliere mic head. To reduce or eliminate the sound of rustling clothes, it’s important if the lavaliere mic head is in contact or secured against the clothing of a person to be in a way that the head will not move around rubbing against the fabric. Hiding microphones under layers of clothing will make the rustle more apparent because it is hearing the sounds of multiple layers of fabric in contact with each other. An example would be if you have a mic head under a collared shirt, that is covered by a necktie or jacket or other overcoat, you will be competing against all those materials on the wardrobe, as well creating muffling the sound. Here are some tips or tricks and places to hide lavaliere heads:
- In the persons hair if appropriate.
- Behind the collar of a dress shirt between the skin inside is a good place to tape or vampire clip a microphone head.
- Underneath the collar or if there is room between the mic head and the fabric place the microphone head in the gap under a shirt collar, but don’t put it under a necktie. This is best in the gap between the shirt and the skin, near the top or top button area in this space.
- Protect the mic head with a rolled tape barrier against the skin. Avoid underneath layers of clothing.
- In the valley (a woman’s bosom if permitted), but away from clothing.
- Using Rycote Stickies to stick the heads to a less noisy portion of clothing can help.
- Slightly exposing a lavaliere head in a necktie knot or pocket near the talents head & mount is also a solution.
- Using a Rycote Stickie, or protected tape barrier inside a roll of tape that is under the collar, between the shirt or underneath a shirt without layer contact from other clothing will work as well.
- If you have disposable wardrobe, cutting a tiny whole and slightly exposing the mic outside a jacket pocket, or other garment nearer to the person’s mouth or as close as possible will work as well. Secure the head with tape just out of view, behind the fabric. If you have colored tape, use this to match color of the wardrobe or use a colored mic head if you have the budget. Countryman makes several colored choices for B3 and B6 microphones.
- Moleskin from Dr. Scholls can be used to secure a lavaliere head to clothing, underneath clothing and can also assist in reducing rustling from clothes, caused by mic heads hidden as well if it is properly taped securely. You may need to use tape just under the portion of the mic head condenser or diaphragm to secure moleskin to the clothing. Moleskin protecting the entire outside of the lavlier head, affixed by tape underneath clothing is a great trick to reduce the headaches of hidden lavaliere heads contacting clothing if you keep the microphone head from moving inside the moleskin, as well secure the entire portion to the underside of the garment working with male or female talent.
- Lavalieres can be suspended right on shotgun mics for interviews to almost completely eliminate all clothing rustle which is caused by the mic head rubbing on the clothing). This will work when the person is not moving distances over a foot, and better if they are sitting or standing in the same spot. This can be used as a backup mic to the use of a shotgun microphone.
- The best mic heads in my opinion for hiding are Countryman B6 heads, that fit Sennheiser & Lectrosonics most commonly. They also have a hard wired version that connects by XLR cable as well.
- The editor can also rely on a good use of a shotgun microphone and a good sound persons placing techniques making the shotgun the primary source, pending the ambient noise conditions), and using the lavaliere as a back up. The editor can also rely on another lavaliere if in reasonable proximity when clothing is slightly or not noisy), say for instance, 2 separate actors are talking to each other with 2 separate microphones, with assignments to separate channels or tracks in the audio recording. You can use the lavaliere of the other talent if needed if the sound is par or use the boom if one can be used for the preferred audio track.
- The smaller the surface of the mic head, the less noise it will pick up from clothing. Clothing rustle can be made more by silk, polyester, or other fabric combinations.
- Double stick tape / double stick / sided gaffers tape can also secure a mic head to a person and secure the garment to the skin (without causing pain), and reducing any clothes rustling sounds as well.
- Also recording isolated tracks with referenced time code is more ideal with all microphone & wireless sources separated from each other will allow the editor more freedom. Also if the actors or talent are close to other microphone sources, using another mic off the person can also work when wardrobes are not cooperative. So lavalieres in proximity can be used to back each other up especially when talent is close to each other.
- Reduce the size of your lavaliers mic head (the condenser element or diaphragm.
- Use microphone heads that are the same colors of your talents apparel or camouflage the head & cable with colored tape that is less adhesive.
- Slightly exposed microphone heads secured by tape can be very successful at not conducting noise from clothing or skin.
- Most importantly test out the hidden mic before the person(s) go on camera and troubleshoot if necessary. This is critical for any production, and commonly done with feature film production. Using stand ins to test audio before hand wearing the same wardrobe will also help you get cleaner sound, as you take to to prepare and solve any wardrobe issues disrupting your sound recording before the Money Shots.
- Use a shotugun microphone as a backup to your lavaliere microphones or visa versa.
- Or you can in some instances neatly dress the lavaliere outside the talent either out of camera frame or to the clothing in interview situations.
Here’s an article to another sound mans tips on hiding lavaliere heads on people – http://www.dvxuser.com/V6/showthread.php?203757-Hiding-a-Lav-Mic-Good-info-I-found
Here’s a link to other tips on YouTube.com on some ways to hide lavaliers on people: https://www.youtube.com/results?search_query=Hiding+a+Lav+mic
These articles are provided by Nick Teti, a freelance sound recordist; local in Denver or Colorado. Nick provides sound man services, also known as a sound or audio guy, audio tech, sound recordist or mixer services and other related services in all CO, as well, traveling for video, film, television & radio productions.
Dumb syncing or slating
Using the slate clapping method, started in film production before video production, including early days of television production, as well adapting to recent technologies, such as in the use of DSLR cameras or other cameras that don’t have a time code port or audio input ports or audio ports with internal mechanisms that are not as sophisticated to record good, clean sound.. It’s still widely used today in a method of clapping a slate while rolling sound & camera before the slate is clapped where the editor can later look up the frame where the slate makes contact between the separated top & bottom elements, and matches this to the waveform on the recorded audio file. The loudest part of the waveform at the beginning of the recording typically matches the video or film that has the slate in the picture clapping or making the first contact. To help the editor, it’s critical to see the slate clapping before action occurs to see the match between video or film and the audio files.
The video file or film roll can be referenced in the audio recording before or after the slate clap, at the beginning and end of the file as well if critical, this also helps the editor. Typically the camera operator informs the sound recordist the take # or name. A slate mic on the mixer will assist in recording the referenced video or film take for the sound recordist or sound crew.
Time Code Sync
Using time code embedded into the audio file, referenced from the time code out port of the camera enables the editor later to sync these time codes from the video, as well the audio together. This also applies to film production in instances of 16mm, Super 16, 35 or 70mm formats if the camera has a time code port. The sound recordist can also get time code from a more recent film camera, with most either being 35mm or 70mm formats. Many/Most film all stocks do not have a way to embed time code physically onto the film so the DP or camera operator or other person in the camera department must coordinate with the sound recordist or crew to set matching time code. Sending time code out from a film camera to the sound recordist is the easiest method to reference the film picture to the sound recorded.
Time code can be sent from the sound recordist into the camera making the time code match the recorded audio files from the sound recordist or the camera operator can send time code to the sound recordist to embed time code into their recorded files.
Audio Directly to Camera
Audio straight into the camera recorded simultaneously with sound & picture is synced.
Free Run Time of Day
Setting the recorder or mixer recorder’s frame rate to the cameras frame rate along with starting the recorder and camera at the same time code start then letting them free run in non drop frame will also work. It’s called jamming time code. Drop Frame time code will drift from sources as each device will drop frames at varying intervals, and not consistently the same rate. DROP FRAME drops randomly, and not after each second or x amount of minutes from device to device. You can send time code from camera to recorder or recorder to camera to sync them initially then let them free run on the same frame rate. It’s good idea to check this frequently, but the drift will be fractional over days with these methods. You can use a non drop frame rate like 24, 25, 30, 50, 60 with a non drop to avoid drift after you jam timecode camera to mixer or other device.
Free Run TOD timecode is ideal of the sound recordist and camera person cannot stay connected together during recording and there are no lock-it boxes or tentacles available to keep time code in continuity. As a sound man, I use tentacles when disconnected from the DP or camera operator or videographer. Another solution if your camera does not have a time code port is to use a cell phone time of day and match the camera, as well other devices to free run time of day in a matching frame rate and start them running at the same time. You can do this either in a NON Drop format or DROP FRAME TIMECODE. People have argued that drop frame time code is not consistent from device to device, but I can only comment that no frames are DROPPED in DF TIMECODE, just the numbers are dropped according to what I have read. Drop Frame was invented for master control operations, and may not be as necessary on the production side on time of day time code, as it can be converted in post production or your final program. Read more about DROP FRAME timecode by this wiki search link that opens in a new tab or window. I can do all frame rate recording for audio sync in NTSC or PAL. from 23.98 to 60. Under and overcranking typically is not a function of audio sync and many cameras when over or undercranking do not record sound, that is typical over 60 fps. 59,94 frame rates are closest to 60p in many mixers/mixer recorders. I can also record sound of course if you are under or overcranking the camera because I’m that type of sound guy.
Lock-It Boxes and Tentacles or Wireless
Tentacle’s are a simple wireless lock-it box device that are easy to operate. The only downside is not being able to sync multiple Tentacles by the iPhone or Android app to time of the cell phone. However you sync from Tentacle to Tentacle or from Tentacle to camera and or mixer recorder. Tentacles have a very low drift factor and battery life making them ideal for longer shoots. Tentacles have adapter cables to sync to phones, Andriod devices, mixer/recorders, BNC ports, cameras and Lemo connections, as well the mini port allows them to send time code into DSLR or other devices that have a mini connection. My personal choice as a sound guy is the Tentacle over a Lock-it Box for wireless syncing.
Lock it boxes are varied in manufacturer but are a reliable wireless method to get time code, but some do not have the syncing interface ease of mobile devices like iPhones or Androids without applications help. Some are better suited to direct time code ports like BNC or Lemo to BNC for connections with less diversity between common or uncommon time code connections like an iPad, iPhone, Android or other mobile device, in addition to a mixer/recorder or camera. Tentacles have an advantage in you can set them up with these mobile devices as well, as cameras or mixers.
Lavalieres with Adapted Cables
Wireless microphones with a transmitter and a receiver can send time code to an XLR channel input or other audio input, effectively giving the other channels a reference signal where an editor can use editing or syncing software to match time codes later in post production. The wireless system needs to be able to input and output a LINE LEVEL signal to match the characteristics of SMPTE time code. The sound recordist still needs an adapted cable in certain instances to send the timecode into the camera or mixer or recorder. If you use the AF out connection from the receiver into the camera’s or mixer audio input, you send time code to an audio channel. Or adapt the AF out of the transmitter to the input of the mixer or camera or other recording device time code port. You will probably need adapted cables from the camera or mixer into the transmitter as well, adapted cables from the receiver to input and output to the time code connections of each. As a location sound mixer, I’ve done this before, but have other methods and hardware I use before doing this.
Editing Software and Audio Software for Sync
Video Editing Software
Newer versions of Adobe Premiere, Final Cut X and Davinci Resolve, AVID have syncing capabilities as well, but remember that it’s better to sync with all the methods in tandem mentioned above such as audio directly into camera, time code referenced recording and slating if you have the time.
Tentacle Sync Studio, PluralEyes are common applications I have used to sync audio together as well many other video editors, (aside from being a veteran sound recordist, I am a seasoned video editor as well).
Contact by telephone at (720) 299-2084
Email Address Directly Below
Skype: Nick Teti or misterphotonmedia (Colorado)