Location Sound Mixing Equipment

By R. Taylor

This article is meant to act as a guide for people who are curious about the equipment involved in working as a location sound mixer in the film/television industry.

I will only be covering the very basics of what you will need to work efficiently. For a more in-depth description, please check back soon for a more advanced article.

Most professional sound mixers have acquired thousands of dollars worth of equipment, and are usually prepared for any situation they are faced with. Gaffer's tape, sound blankets, batteries, and more; these items may be necessary, but we'll only be discussing the most important tools of the trade. Without these key items, a sound mixer wouldn't be able to function.

A sound mixer's toolkit starts with his microphone(s), his mixer, his cables, and in many circumstances, his recording device. In this article we will assume you are going to be recording the audio direct to camera - meaning the same device that is capturing the video footage will also record the audio. This arrangement is common for filming documentaries or low budget films.

The Microphones

The sound mixer's microphones capture the majority of the sound you hear in movies or on television. The two most common microphones used on set are shotgun microphones (aka a "boom mic") and lavaliere microphones (aka a "lav").

A shotgun microphone is a long cylindrical object that is most sensitive to sound waves that come from the direction it is pointed at. It is usually attached to a long pole (boom) and suspended directly above, and in front, of the actor's mouth. Aimed properly, this microphone can produce a highly accurate recording of dialogue, and other noises made on set. A shotgun microphone is an essential tool for working as a location sound mixer.

When choosing a shotgun microphone you should research and test as many types as you can. Sennheiser makes several shotgun microphones that are commonly used by professionals. Neumann offers some excellent shotgun microphones, but they're in the higher price range so they may not be suitable for those of you who are on a tight budget. If you're looking for something a little more budget friendly, there are some excellent microphones from Audio-Technica and Rode.

Lavaliere microphones are miniscule objects that are often pinned to the actor's clothing. They are aimed towards the speaker's face and capture sound waves emanating from the mouth and chest. They are usually connected to a wireless transmitter and sent to the mixer that way. This allows for the actor to move freely without being restricted by cables. Lavaliere microphones can be used in combination with a shotgun microphone, or alone, when a boom cannot reach the appropriate position.

Some lavaliere microphones come as a package deal with a wireless transmitter/receiver but they can also be purchased individually. Sennheiser makes a very popular and affordable model called Evolution.

The Boom Pole

A boom pole may seem like a simple device, but it takes one of high standards to work well. It looks similar to a thick fishing rod, and has a handgrip at one end and a microphone stand connection at the other. They come in many lengths, materials, and weights. They can also be "cabled" which means they have an internal cable that allows you to not worry about wrapping a cable around the pole. These can work well, but many professionals use a regular (un-cabled) boom pole because of its simplicity and reliability.

A standard pole is between 9 and 12 feet and made from aluminum or carbon fiber. The lighter the boom pole the better, as you will be holding it above your head for long periods of time. Don't worry, you'll get used to it.

The Wireless System

To transmit the electronic signal from your lavaliere microphone you will need two things: a transmitter - to encode and send (transmit) the signal from the microphone; and a receiver - to decode and receive the signal before sending it to the mixer.

A transmitter is a small rectangular box that is usually worn in the actor's pocket, or clipped onto their belt. In simplistic terms, this device receives an electronic signal from the microphone and sends it through the air to be captured by the receiver. The receiver is a similar looking object that does the exact opposite of the transmitter. It receives the signal from the transmitter, changes it back to an audio signal, and sends it to the mixer, It can be conveniently stashed in your mixer's bag, which allows an easy connection to your mixer. A wireless system acts almost like an invisible cable.

Wireless systems can be purchased as a set, or individually.

The Mixer

The mixer is one of the most important parts of your equipment. For location sound mixing they commonly come in two to four channel models that easily fit into shoulder bags so you can mix while walking around. The concept is simple: the mixer receives the signal from the microphone(s) and allows you to adjust the volume of that signal. It then combines each individual microphone signal in to one stereo signal (two outputs - left and right) that is then sent to the recording device (i.e. the camera).

Each mixer has different parameters that allow you to pan the signal to the left or the right, send phantom power to your microphones, cut the low frequencies, and much more. It's important to invest in a high quality mixer so that there is no signal degradation. Higher quality mixers usually come with more options and last a lot longer. A good starting point is the Sound Devices MixPre, an affordable two-channel mixer that is very similar to the industry standard "442" four-channel model.

The Cables

Cables are another important (and necessary for obvious reasons) link in your audio chain. Audio cables with an XLR connection (commonly called "mic cables") connect the microphone(s) to the mixer and then connect the mixer to the camera (or other recording devices). You will need at least three 15-20 foot microphone cables for this purpose.

A good idea is to invest in a break-a-way cable to connect your mixer to the camera. These can be quickly disconnected allowing you to connect and disconnect from the camera without getting in the way. It also helps keep things neat and tidy - very important on a busy set. These cables also come with a monitor cable that sends the signal back from the camera, allowing you to hear what the camera hears. Without this, there is a risk of signal distortion that can go unnoticed until it is too late. Bad audio is always blamed on the sound mixer, so be careful.

Although cables seem as flexible as a rope, they are actually quite fragile and need to be taken care of. Cables must be wound properly so that the interior materials don't bend the wrong way. If this done incorrectly, cables can become internally damaged and short out (this causes a loss of audio signal, and can be heard as a crackling sound).

Take care of your audio cables and never wrap them around your arm or tie them in knots. You'll only end up with damaged cables and a higher credit card bill.

The Headphones

You'll need a good pair of headphones to be able to monitor the audio signal coming from your mixer. This topic is fairly self-explanatory. The industry standard headphones for location sound mixing are the Sony MDR series, but any will do as long as they surround your ear, and provide a clean sound with a fairly flat frequency response.

The Clothing

The clothing you wear as a location sound mixer isn't something that will get you hired or fired, but it's worth a quick mention. Some sound mixers wear all black clothes so that they can easily blend in - or not be noticed - if they accidentally get caught on camera.

Pants with a lot of pockets can work wonders when you need a convenient supply of batteries or wireless transmitters. Oh, and comfortable shoes should always be worn - you will spend most of the day on your feet. You've been warned.

The End...

So now you know what basic equipment is necessary to work as a sound mixer in the film industry, go out there and do it. To cut costs, try and find some used equipment or rent some of the more expensive items until you make some money. Either way, the most important thing to do is get out there and start working. You'll probably have to volunteer for a while, but if you keep going, and always work hard (and with a positive attitude) your efforts will pay off.

Stay tuned for more informative articles about audio and how if relates to the film industry.