How to Get good Audio on Location
Though we may be tempted at times, we can’t shoot down overhead screaming jets or flocks of honking geese. We have to accept those elements as simply part of the “ambient” audio or natural sounds at some locations. So your first challenge is identifying what sounds you want to capture and which ones you want to minimize. Those are usually broken down into two main categories – man-made, and natural audio.
For instance, if you’re filming the spring courting rituals of sandhill cranes in an isolated marsh, you’ll want to capture their natural sounds of their flute-like calls, the flapping of their wings, and the stomping of their large feet. Other natural sounds that you might not want to overpower the cranes could be wind whipping the cattails, insects buzzing around you and your camera, and a pesky red squirrel scolding you from some nearby brush. To “mitigate” those sounds, you might place your directional shotgun mic in front of your camera by several feet to rid yourself of the bugs. A quality windsock over your mic will take care of those gusty breeze sounds, and a couple of tossed sticks or a pile of peanuts should silence the red squirrel. It’s up to you to decide what mix of natural audio you want to capture that will help tell your story.
Now let’s consider the man-made audio. Although it’s supposed to be quiet in an isolated marsh, the reality of overhead jets, distant farm machinery, dirt bikers on wilderness trails, camera noise, your crew whispering, can all conspire to pollute the pristine sounds of your cranes. We can’t use sticks and peanuts to quell all those sounds. Yet we still have some control over mitigating them. We can wait for the jets to pass or the farmer to take a break. Or, we might get more aggressive by going and explaining to the farmer or dirt bikers and other man-made sources of unwanted audio, that we’re filming cranes and we’d really appreciate a period of quiet. Some people will look at you like you’re nuts, while many will appreciate your challenge and work with you. If you ask politely with respect for other people’s activities, you might be surprised what you can achieve. We typically try to hush unwanted man-made noises in the form of chainsaws, lawnmowers, vehicles, PA systems, talking people, radios, copy machines, and cell phones.
If your film includes expert interviews, you may actually need to record man-made audio – which is the spoken voice of your expert. This is when you may want to minimize both natural ambient audio and other man-made audio. Fortunately, wireless lavaliere microphones are small dynamic mics that primarily capture the audio in close proximity to the microphone. So when it’s placed near a person’s mouth, usually on their clothing lapel, (that’s why it’s also commonly called a “lapel mic”) it mostly picks up their spoken audio and minimizes any audio in the distance. This video shows a few ways to mount that lavalier microphone.
But don’t rely entirely on your lavaliere microphone to only capture the clean voice of your expert while filtering out background noise. Again, take control of your shooting environment. If you’re doing science stuff, you’ll quickly find that most science labs are awash in various distracting audio that threaten to rob the words of your talent. Although you can’t hush all the devices inside a science lab, here is a hit list of some ambient noisemakers that you may be able to turn off, deactivate, move off location, or stuff a rag in to:
- Humming fluorescent lights
- Air conditioning or heating systems (adjust thermostat)
- Running water, bubbler pumps
- Radios or and music sources – (common in labs and some work places)
- People in conversation – politely explain the situation and ask them to be quiet or leave the area.
- Copy machines, lab machines, phones, office and lab devices that make noise – turn off, unhook, shut doors.
Now that you’ve taken control of the audio in your shooting environment within practical limits, it’s time to turn your trained production eyes to the visual part of your shoot.