How to Get Pro Audio for Your Pro Video
By Steve SavanyuAlthough we’d like to think that the power of the Video Ministry’s vision will absolve any technical discrepancies with the strength of spiritual impact, this is often not the reality. A sub-standard (or worse) audio track can actually ruin a great video. And because your team worked so hard to script, shoot, convert and edit the footage, it would be a shame to let it go with that nasty audio track that made it sound like you captured it with a cheap-o handicam. What to do?
Common Mistakes
The most common mistake that most video ministries make, is not even thinking about audio. Since most of us are visual people, we spend a considerable amount of time on how the scene should look and take sound for granted. Often the built-in on-camera microphone with its automatic gain control is used to capture audio from a subject who is 10 feet from the camera in a very noisy environment. The resulting audio is negligible at best and many times just plain unusable.
The purpose of this article is to help educate your production team on how to avoid many of the common audio mistakes when producing video. We will assume that you are creating content that will become part of a worship service, and not just recording the service for distribution to shut-ins.
So, how do we capture good audio?
First and foremost, avoid the use of on-camera microphones, as they are susceptible to picking up any camera mechanical noise along with any talking by the camera operator or others close to the camera. If you are just shooting b-roll or establishing shots, the camera mic can be used to capture “wild” or “nat” sound, but not key dialog.
Second, always make certain that your microphones are as close to the sound source as possible. This means using external microphones and placing them on or very near to the talent. Many folks will confuse a shotgun mic’s operation with that of a telephoto zoom lens. The telephoto zoom lens has the ability to “bring the subject in closer” to fill the frame. Unfortunately the laws of physics in audio and acoustics don’t allow this to happen with sound. Thus, if the subject is 10 feet away, he will always sound 10 feet away, even when a shotgun mic is used. Basically what a shotgun mic does is isolate the on-axis or desired sound by rejecting unwanted sound from the sides of the microphone.
Third, always monitor your audio with good closed-back isolating headphones. Just because the audio level meters in the camera are moving, doesn’t mean you have good audio. You might find in fact that you are actually picking up the loud sounds from the highway behind your talent or the room’s noisy HVAC system, and not the desired interview dialog.
Fourth, be aware of the background audio at your location. Our ears are “amazing miracle microphones”, having the uncanny ability to isolate certain sounds while ignoring all of the other sounds around us. A good example is the “Coffee Hour” between services. You are chatting over a cup of joe with the most boring person in the world (pastor’s wife?). However, there is some interesting conversation about the new young youth pastor going on near you.
With our ears, we can block out the wife... and focus in on the juicy conversation nearby. If you were to put up a microphone, record the same scene and play it back, all you would hear is a jumble of voices. So, before you roll tape, have everyone on the location be quiet. Listen carefully for sounds you might not normally be aware of such as: air conditioning vents, traffic noise, people in nearby rooms talking, refrigerators and other machinery. Deal with these undesired sound sources by turning things off or re-orienting your microphones so unwanted sounds can’t be picked up.
Finally, be familiar with what your equipment can do and make certain all of the accessories are packed for the shoot. Don’t forget expendables like batteries, gaffers tape, cables, windscreens, etc. Leaving some key accessory behind can cause the production to grind to a halt while you run back to get it.
Gear Checklist
It all depends on the situation and what you have on hand. For a basic interview shoot you should carry lav mics for the subject and interviewer, a shotgun mic in case you can’t use the lavs, a boom pole for the shotgun, cables, headphones, appropriate interface box if needed to connect mics to the camera, gaffers tape, spare batteries if the mics require them, and all of the appropriate lav mounts (especially if you don’t know who you have to rig the mics on). You may want to consider carrying a small zipper pouch with scissors, moleskin pads, sticky first-aid tape, and safety pins to aid in attaching mics on clothing and dressing the cable to minimize the pickup of clothing noise.
Some people like the convenience of wireless microphones. If you plan to use wireless, make certain you have a set of open available frequencies for each one. The Audio-Technica website can help in choosing frequencies based on your zip code. Always carry spare transmitter and receiver batteries, along with a couple of 30’ mic cables, just in case the wireless system gets interfered with and you need to go to wired mics. Plus make certain you have wired counterparts of the mics you are using or the proper interface adapters for the wireless mics.
You should have a standard gear “punch list” with two columns (Out & In). This way you can check to make certain you don’t leave anything back at home base, and when packing out at the end of the shoot, confirm that you have accounted for all of your gear.
Shotgun Vs. Lavalier
Shotgun Microphones
Traditionally a shotgun microphone mounted on a boom pole, controlled by a skilled operator, is the mic technique of choice in many productions. Having the mic close to the talent allows for optimum sound pickup while rejecting unwanted background sounds. Booming from above provides balanced natural dialog and also allows the mic to pickup footsteps, and other desired sounds if the talent is moving. When dealing with an interviewer and subject having different voice levels (loud vs. soft), a practiced boom operator can take advantage of the microphone’s pickup pattern placing the louder talker slightly off axis and the softer one on axis to balance the voices. Finally in some instances it might be impractical or difficult to wire up the talent with lav mics thus making the boom the only choice.
As an alternative to booming from above, booming from below can provide satisfactory results if done carefully. When booming from below, be aware that the mic has a tendency to pick up more of the chest resonance, which can muddy up the dialog. Also be aware of what is above and behind the talent as the mic is sensitive to those sounds as well.
When using a shotgun mic, try putting a strip of white gaffers tape around the tip of the mic’s windscreen. This way the camera operator can see if the mic dips into the shot as the contrast between the tape and windscreen show up well in the camera viewfinder. Then you can dip the mic into the frame during a shot rehearsal (with a resulting “boom in the shot cry from the DP”), allowing you to set a visual reference of how close in you can put the mic.
When using a directional microphone outdoors, protect it from wind with a good windscreen. Although the foam windscreens included with the microphone are ok indoors or outside on a windless day, a good “fuzzy-type” windsock will provide maximum wind protection without compromising audio quality. Before rolling tape, take a moment to “fluff up” the fuzzy’s fur for best wind isolation. And if all you have is the foam windscreen that came with the microphone, simple techniques such as placing your body between the wind source and talent can help some.
The disadvantage to a shotgun mic is that it requires a person to hold and position it. An alternative would be to use a shotgun mic/boom pole affixed to a stand and aimed at the talent. Often called a plant mic, the mic is literally planted someplace and aimed toward the action. A C-Stand with a boom pole holder or even a regular mic stand can work. Always remember to keep the mic in as close as possible.
Lavalier microphones
Lav mics attached to the talent are another way to capture good clean audio. Of course, care must be taken when attaching the mics so that clothing or cable noise isn’t picked up when the person moves. For a basic interview locate the lav mic on the person’s lapel about 6-7” below their mouth. A good rule of “thumb” is to have the person make a “thumbs-up fist”. While placing their thumb on their lower lip, make note of where the bottom of the fist hits their chest. This location would be a good starting point for the Lav.
Lavalier mics come in two “flavors”, Transparent and Proximity. A transparent lav is typically omnidirectional and has a smooth natural sound with no proximity effect whereas a Proximity lav has a directional pattern (typically cardioid) and some proximity effect which can enhance chest resonance and minimize the pickup of undesired background sounds. However, when wearing a proximity lav, the person must take care to move their head and body together (turn at the hips, not at neck) so their voice does not go in and out of the mic’s pickup pattern resulting in varying levels as the person moves.
Unless there is a lot of undesired background noise, a transparent (omnidirectional) lav is first choice.
Often lavs will be connected to a wireless transmitter for convenience and to provide freedom of movement for the talent. Unless it is reality TV or a situation where the person is doing a lot of moving around, I prefer to use wired lavs and mic cables. They are an inexpensive insurance policy against drop-outs, battery failure, etc. However one must take care when running the cables.
When rigging lav mics on the talent, take care when mounting them and dressing the cable. Use a “broadcast loop” to bring the microphone cable back thorough the clip, securing it with the back of the clip. This will minimize pickup of any mechanical noise travelling up the mic cable. Other rigging methods using moleskin, safety pins and sticky tape allow the mic to be hidden on the person while minimizing the pickup of cable noise and clothing noise. Be aware of what the talent is wearing and suggest that they do not wear nylon or other synthetic material, as these are more susceptible to noise pickup. Try to also have them avoid wearing overly starched shirts, jewelry, medallions and other accessories that can make noise if they touch or rub against the microphone.
If your lav mic or shotgun uses a battery, make certain that it is fresh before a critical shoot. Although the batteries in a wired mic can last a long time, carry a spare just in case.
Closing Tips
Always monitor what is being recorded with good closed-back headphones. Pay attention to background sounds and undesired sounds that might affect the recordings. If possible turn off air conditioning, HVAC systems, things with motors or compressors, and other noisemakers. When recording, tell other members of the cast, crew and bystanders to keep quiet. At the end of shooting, record a little background sound with no talking, etc. This “room tone” can sometimes be used during post production to cover up discrepancies in the audio. For example, an actor flubbed a line that went unnoticed until postproduction. The actor came in and rerecorded the line in the studio. By adding some of the previously recorded room tone, it was possible to seamlessly blend this line into the rest of the dialog.
Always carry spares, especially if it is a one-time, critical event or it is difficult to go back for a retake. Spares at the minimum should include: microphone cables, batteries if needed, and a spare microphone, just in case…
