“The power of sound has always been greater than the power of logic.” - Joseph Conrad
There’s a firm axiom in filmmaking philosophy: audiences can tolerate bad picture quality, not bad audio. At first, this may seem counterintuitive. After all, aren’t films moving pictures; shouldn’t the image be paramount?
But upon closer inspection, you may recall movies like “The Blair Witch Project” or the recent “Cloverfield”. These films were basically shot with a wild, handheld camera and yet were tolerated, and even enjoyed, by general audiences. This is because the audio was still top-notch, despite the pedestrian filming technique.
So, as you bust out the old handy-cam from 1984, don’t fret. While your images may be suspect, there are still steps you can take to ensure quality audio capture. Below is an introductory view into the world of recorded sound. For those interested, further information is readily available and delves into much denser and more complicated material than that below. We provide here only a broad overview for the novice who wishes to dramatically improve the professionalism of his/her MindBite.
There are basically two different categories of mics: dynamic and condenser. The subcategories for these two branch off into several winding directions, but the main distinction between the classifications are that condenser mics require electronic power while dynamic mics do not.
Dynamic microphones use either moving coils or corrugated metal ribbons suspended in magnetic fields to produce sounds waves that are converted into electrical signals and sent down a cable to an amplifier. It’s all very complicated and quite outside our understanding, but dynamic mics are generally more robust and less expensive than condenser mics. Because they require no electrical charge, they are water resistant and are generally the type of mic you’ll see in the hand of a singer or speaker on stage.
Condenser mics produce electrically charged signals, which make the mics much more sensitive and powerful instruments. They are usually quite delicate and can range from cheap throw-away mics to high fidelity equipment. Because they allow for heightened sound sensitivity, they are the preferred mic for studio recordings and film production. For their power, they require either an on-board battery or what is called phantom power, which simply means that the power is derived from a third-party source, like the recording camera.
Aside from the above distinctions, mics may also be classified by their recording patterns. These polar patterns describe how sensitive the mic is to sound sources located at different angles from the mics central axis. The importance of this feature deals with control. Sometimes, a recordist may wish to gather all the sounds from the surrounding environment, in which case he will want a mic that records in a 360˚ pattern. Other times he will desire only sounds from a specific source and will choose a mic with a narrow pick-up angle, thus limiting interference from other sources.
This aspect is best described using diagrams. Below are illustrations of different microphone pick-up patterns, the protruding bubble representing the directionality. You’ll note that many mics have a smaller bubble emanating from the behind the pick-up, meaning that sounds may register even if the mic is pointed away from their source.
Mic application varies widely depending on the circumstances in which they are to be utilized. For this reason, there are several forms mics may take, each with their own specific usage.
Now that we’ve gone over the different types of microphones and how they record sound, let’s try to figure out what this all means to you, the MindBiter. More than likely, your home movie camera has nothing attached to it that even remotely resembles the designs mentioned above, and yet it still records audio, right? Well, if you look hard enough, you’ll probably find little holes located in the front of the camera. This is the windscreen for your camera’s so-called microphone. But let us impress upon you, these on-camera mics are pathetic and the sound quality they record is far below par.
This is why we highly suggest buying an external mic that’s compatible with your camera. You don’t have to lay down big bucks for a proper instrument, an adequate mic can easily be purchased for less than $100, and the sound quality achieved from such is exponentially greater.
Pictured here is one of the consumer mics we use at MindBites. Not only does it dramatically increase the recorded sound quality, but since it isn’t attached directly to the camera, we can move the mic about the space to focus on different sources or on one moving source.
It’s important to be aware of how these external mics will connect to your camera. Many consumer grade camcorders accept 1/8″ jack inputs, which you’ll probably recognize as the the input associated with headphones. However, some cameras, particularly those made by Sony, have their own unique connection input which requires the owner to buy Sony brand specific microphones. It’s important to do the research before purchasing a mic so you don’t end up with two incompatible components.
Professional microphones will generally use XLR inputs, or three-pronged balanced input connections that are more-or-less incompatible with consumer grade cameras. So don’t think springing for the several-hundered dollar mic and attaching it to your cheap Canon will be a financially savvy investment.
Microphones come with a host of accessories one may choose from, and when choosing their equipment, sound recordists often become like kids in a candy store. Of all these, there are two of which the novice should be aware: boom poles and windscreens.
Boom poles are long, extendable rods that are durable, extremely light, and have a holster at one end which houses the microphone (usually a shotgun mic). They are used heavily on film sets for they allow the mic to be placed close the subject but remain out of the shot. The boom operator holds the pole high above his head and positions it so that it’s above the camera’s frame, hiding it from view but getting the mic closer than would normally be possible. Some poles often house a length of cabling that connects the mic to the recording equipment.
Unfortunately, professionally made boom poles are quite expensive. But fret not, for anyone can construct an adequate pole out of an old broom handle and duct tape. Just make sure the mic is adequately attached and the pole itself is light enough so it won’t tire the operator out after only a few minutes.
Windscreens are enclosures, commonly made of a spongey material, which house the microphone and protect it from wind noise. It often escapes our notice in normal life, but even light wind can create an unpleasant whoosh sound when passing over ears, and this effect is amplified with microphones and interferes with a clear signal from the desired source. Windscreens decrease this interference significantly and are absolutely necessary for professional and amateur production alike.
Aside from proper equipment and an understanding of such, there are guidelines you should be aware of concerning good recording conditions. Before you turn the camera on and begin production, make sure you’ve located yourself in a soothing, quite place. Silence those around you and have a quick listen. Are there any extraneous noises present? Listen hard for the ticking of clocks or the hum of appliances, like the refrigerator. If the sound is audible, unplug the source while shooting and power it up again once the shot is over with.
If your microphone is pointed in the direction of a noisy area, like a highway or airstrip, move your subject and aim your shot away from the sound. Also, be weary of rooms with a heavy echo; it will interfere with your speech, making it unintelligible on tape.
Be careful of too much in-camera zooming while recording. The servo mechanics of the camera may be noisy as they move about inside the lens, creating the zoom effect. Sometimes this can register on the audio track and distract from the subject’s speech.
Distance from the microphone can sometimes have a negative effect on sound quality as well. Test out your mic before shooting your lesson. If sound quality differs significantly when you are close to the subject from when you are farther away, then try planning your shot so you are as close as possible, to pick up the clearest audio signal as you can.
Remember that quality audio comes from proper preparation. If you take time to clear your surroundings of distracting noises, position your subject in a good place, and use quality equipment, you’ll be on the right track for clear sound. And, as stated at the beginning, quality audio is a key component to achieving professionalism in your MindBite, or any of your various video projects.
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