Why the Microphone Your Agency Uses Matters (Part 2)
Need a voiceover for a 30-second animation? How about a field recording during a live-action video shoot? Whatever your video project, if you need audio, you need a skilled audio engineer who knows his or her way around microphones and microphone accessories. In this two-part series, you’ll learn all about microphones, what mic equipment you may see at an audio recording or video shoot—and why the right mic can make or break your project.
There’s nothing quite like a live video shoot. The cameras. The cables. The catering. The extraordinary coordination it takes to get everything off the ground.
If you’ve never been to a video shoot, you’re going to have questions about what you see and hear. In this post, we’ll touch on some of the things you’ll see related to audio engineering and microphones.
“Who are all these people at my shoot?”Like we said in Part 1, it takes a skilled team to create a video. You’ll see all kinds of people at a video shoot, including the video director, the cameraman or woman, the gaffer (lighting), the hair and makeup stylist, the talent and more. On the audio side, you’ll see a production sound mixer, also called a sound man, or audio engineer. In a small crew, the sound man may also need to act as a mic boom operator, a grip (lighting and rigging technician) and as a python wrangler (pulling cables).
“Why can’t you just use the camera mic?”Video production requires audio engineers to walk a line between a live, or “field recording” environment and the recording studio, or sound stage. One of the biggest challenges when recording audio for video production is selecting the best mics for the unique filming situation.
Modern video cameras (DSLRs) have built-in microphones. The quality of sound most of them produces falls somewhere on a scale between awful and horrible. The audio collected through the camera’s built-in mic is often used as a disposable “scratch” track. It is then synchronized to, and replaced by, the better quality field audio during post-production.
The job of the camera is to capture the best possible video. Adding a high-quality audio component to DSLR cameras would make those units too large for practical use. It would drive the cost up substantially, and it ultimately could not offer the diverse capabilities that field audio recording demands.
“What’s that mic on top of the camera?”One way audio production can be improved with a DSLR camera is by adding an external mic to the camera rig. High-end video cameras will have a mic input jack and a shoe mount, allowing a quality directional mic to connect to the camera. The external mic, when patched-in, will overwrite the audio collected by the built-in camera mic.
Lots of microphones can be connected to a video camera, but the most commonly used is the “shotgun” mic. Shotgun mics have a long, gun barrel appearance, are mounted atop the camera, and are aimed in the same direction as the lens. Shotgun mics are condenser types and require battery power. Some shotgun mics have level controls to adjust the amount of sensitivity so the sound source can be “turned up” if too soft, or dialed back if needed to prevent volume overload distortion, or “clipping.”
The problem with a shotgun mic is that the camera distance from the subject may be too far away to capture a clean audio. Even though they are highly directional, shotgun mics are still subject to background sound pollution, especially sound coming from behind the primary subject.
“What’s up with the mic on a stick?”Booms are simply a way of mounting a microphone to the end of a long pole so the mic can be positioned closer to the sound source. Sometimes they’re necessary because there are obstacles between the sound man and the subject. But usually, booms are used to keep the mic, the equipment and the sound crew out of the video frame.
Professional quality booms are very light. They’re made from carbon fiber with a built-in mic cable to prevent anything from dangling into the shot. In an emergency, a boom can be improvised with any long dowel or pole, some gaffing tape, and a little imagination.
The boom can be hand-held or mounted. If hand-held, here are some tips and tricks the boom operator may use to make the task easier:
- Cotton gloves are indispensable; a very sensitive mic will pick up the sound of bare hands sliding up or down the boom.
- Sometimes a boom operator has to hold the boom steady for an extended period of time. Even though it may be very light to begin with, after a while, the arms will tire. In that case, boom handlers will often rest the boom behind the neck on their shoulders, using their arms and hands only to steady the mic position.
“What’s that fuzzy thing on the boom mic?”It’s a dead cat—but not the kind that will get you in trouble with PETA. “Dead cat” is a name used to describe a certain kind of wind screen used on microphones when recording outside.
Wind noise can wreak havoc on an audio recording. In extreme cases, it can render the sound you are attempting to record unrecognizable. Even a light breeze can make itself audibly present as it wafts over your mic’s diaphragm. Wind screens create an area of non-moving air surrounding the mic, which eliminates low-end booming sound of wind. Wind screens are indispensable to prevent disruptive wind noise from contaminating the audio.
Like everything else in this industry, wind screens range in price and quality, from a cheap foam muff to elaborate plastic sound cages called “blimps.”
“What’s that tacked to the talent’s blouse?”TV personalities and their guests often clip lavaliere mics, the tiny black microphones, to their shirts or neckties. Lavaliere mics are often called lav mics or lapel mics. There are several kinds of lavaliere mics, and the quality – as with all other mics – is commensurate with the price.
Using a lav mic visually cleans up the video image. A well-placed lav mic may be completely unnoticeable in the shot. Another benefit is that the sound level is very consistent. As the subject speaks and moves, the lav mic remains at the same position and distance from the speaker’s mouth.
The most desirable lavaliere mics are very small, very sensitive and wireless. “Wireless” is a bit of a misnomer. A wireless lavaliere mic does have a wire, but it runs a short distance from the mic to a radio transmitter that can clip to a belt or rest in a pocket. The lav mic receiver then feeds that signal to a camera input or to a field audio recording unit.
Ensure the success of your next video project. Work with a talented video team that knows their stuff—and an audio engineer that knows their way around a microphone.
Note: No cats were harmed during the making of this blog.