Recording Interview Audio for All Budgets
Written by Jay Goodman
A college film student spends days choosing the location for an interview. His team furiously decorates the set the morning before the shoot, while the lighting crew is adjusting their gear. The actors spend two hours in hair and make-up. The host is in wardrobe and it is finally time to start rolling the cameras. Right before they begin their first take, the student director quickly places a cheap microphone on the table in between the chairs. The shoot went smoothly. The footage was perfectly framed and looked fantastic. But,when the interview was edited the dialogue was nearly impossible to understand. The student ended up failing this assignment because he forgot that the most important part of an interview production is the audio. The viewer will lose focus if they can’t understand the words. The student should have spent more time choosing the right microphones and making sure they were placed properly. I will discuss different types of microphones and how to best use them for interviews; and this buying guide will provide an overview of affordable and high-end option for each type so you can find the right tool for your budget.
Before you run any cables, you have to decide on your location. For interviews, you want a location that sounds as good as it looks. This means finding a place free from unwanted noises (traffic, refrigerator, ringing phones, etc). Listen closely to any location before setting up. If you hear distracting sounds, you can be sure the mic will pick them up too. If possible, find a quiet and fairly small indoor room that does not echo. Absorbent surfaces (carpets, couches, curtains, etc) will reduce the amount of reflection and echo in a room.
Capturing great sound starts with choosing the right microphone. There are five common styles of microphones based on their “polar patterns”. Polar patterns are a three dimensional shape around the capsule that defines where the microphone is the most sensitive and where it rejects sounds.
As you can see above, an omnidirectional microphone captures sound everywhere around it in a sphere. A cardiod mic is directional and captures sound infront while rejecting most behind it. Hypercardiod has a tighter forward focus than a cardiod, but does not fully reject sounds from behind. A bi-directional microphone captures two ovals on either side while rejecting sounds 90 degrees off axis. Lastly, a shotgun microphone is the most focused directional mic as it has a narrow field of sensitivity directly in front. Because it has small areas of sensitivity on the sides and back, relatively minimal sound is captured there. Shotguns are very effective at rejecting unwanted sounds.
The shotgun style microphone is very popular for recording speech in interviews due to its highly directional nature. This allows the sound operator to focus the microphone on the voices while minimizing environmental and other distracting sounds. Some shotgun microphones are mounted directly to DSLR cameras. For an interview, this would be too far away from the sound source. To solve this problem, boom poles (such as the K-Tek KEG-60CC Avalon Series ($355.50)) are used to get the microphone as close to the actors as possible without being in the shot. As a rule of thumb, you should point the shotgun mic in the direction of the area around the interviewee’s chin.
Sennheiser MKH 416($999.95).
The top-of-the-line shotgun mic is the Sennheiser MKH 416($999.95). This mic is regarded as an industry standard for recording human speech. If you have ever seen a movie trailer that begins with a deep voice saying something like, “In a world where…” chances are it was recorded with this mic. This is the microphone for professional sounding dialogue. The MKH 416 features rugged construction, low self-noise, and a low proximity effect. The MKH 416 will require phantom power (+48v) in order to operate. On the budget side we have the versatile Azden SGM-2X ($214). This microphone comes with two detachable barrels. The first is a 16” shotgun style directional barrel, which is ideal for interview audio. The second barrel is omnidirectional, which allows this microphone to double as a handheld or environmental microphone. Additionally, this battery-powered mic can be mounted to a DSLR camera as well as attached to a boom pole for maximum versatility.
Azden SGM-2X ($214)
Lavalier (lav) microphones are another very popular choice for recording interview dialogue. Lavs are small omnidirectional mics that can be clipped or taped onto the actor’s clothing, usually hidden near the collar or lapel. With the exception of low budget productions or perhaps reality shows, you will never see a lav microphone appear on a character in a film.
A lavalier microphne
Lav mics have the advantage of always being the same distance from the speakers voice but also can fall victim to interviewee error. The interviewee might accidently rub the microphone with their clothes, or gesticulate, creating unwanted sounds. On the high-end of the market is the Countryman B6 ($299). The mic itself is not much bigger than a plump grain of rice. The cable is remarkably thin and discrete. This incredibly small profile makes the B6 weightless to the actor and easily concealed for the camera. The omnidirectional pattern minimizes handling noise, wind noise, and plosives, making it ideal for interviews. The B6 would typically be used in conjunction with a wireless transmitter pack, which can cost more than the mic itself. Having a wired lavalier microphone keeps your actors on a literal leash and restricts their freedom to express through movement. There is a budget way to avoid the pricey wireless pack. First, you find a low cost wired lav mic like the omnidirectional Audio Technica ATR2250iS ($21.99). Next, you purchase a low cost digital recorder such as the Zoom H1 ($99.99). You attach and conceal the lav mic on your actor and then run the cable through the shirt and into a pocket. You plug the lav mic into the Zoom H1, check levels, press record, and leave it in the actor’s pocket. With this DIY lav pack you can take the leash off your actors for under $125. For an even lower budget option, the ATR2250iS comes with an adapter that allows you to plug in and record to your smartphone. That means you would have to give up your phone for the whole shoot. You shouldn’t be taking calls or texting on set, anyway. It is important that the whole crew has their phones on airplane mode or turned off when rolling. Yes, the ringer is a problem, but the real concern is induced cellular interference (digital hash) when recording audio. Even a phone on silent can ruin an audio take if it is still receiving cellular signal. Airplane mode or off are the only options when on set.
From left to right, The Audio Technica ATR2250iS ($21.99) and the Zoom H1 ($99.99)
Handheld microphones are the iconic “reporter on the street” style mic. They are held in the hand of the interviewer and it is often moved back and forth between people during an interview. Unlike a lav or a shotgun mic, the handheld mic is used by the actor or interviewer and will be seen on camera. For that reason, these types of mics are only used when it is appropriate to have a microphone in the frame. The optimal position for a handheld interview microphone is a couple of inches below and infront of the speaker’s chin, pointing up at their mouth. Handheld microphones are omnidirectional because of how much they move while recording. There is a good chance that the interviewee may turn their head suddenly as they speak, and themic will have to sway to follow them. When using an omni in this situation, the microphone isn’t trying to cancel out ambient noise from the sides, so the sound is going to maintain a more consistent level. For example, if you used a cardiod mic in this situation, you would get a dip in your audio level and likely miss what they are saying. By design, omni microphones have less handling noise than cardioids. Handheld microphones are mostly dynamic and do not require external power or batteries.
From left to right, the Beyerdynamic M58 ($259) and the Audio-Technica AT8004 ($99).
A professional model is the Beyerdynamic M58 ($259). The internal shock-mount of the omnidirectional M58 reduces handling noise. The internal frequency response has been specially tuned capture accurate and intelligible sound. The rugged M58 features an extra long body that allows the mic to be placed close to the mouth without arm fatigue. The Audio-Technica AT8004 ($99) is a lower priced handheld option. Also an omnidirectional, the AT8004 provides a forgiving pick-up area for talkers who tend to move and change directions. For ten more dollars you can get the Audio-Technica AT8004L ($109). Functionally, they are the same microphone. However, the 8004L has an extra long handle that allows the interviewer to relax their arms as they hold the microphone.
So which microphone should you use? The answer is: the more the better. Most productions use shotgun and lav mics simultaneously. This allows at least one backup audio source. You never know what is going to happen once you start rolling. An interviewee might get cold and put on a sweater over their lav mic, which would muffle the mic’s ability to record properly. One of the microphones might pick up some radio interference. Or worst yet, one of the mics might not be recording at all. Multiple sources of audio will allow you to mix and match to hide mistakes and generate the clearest interview audio. That being said, the shotgunmic on a properly handled boom will likely yield the highest quality audio. Regardless, backups are a must. Lastly, and most importantly, use your ears when recording dialogue. Experiment with different mics and placements the same way you would change lenses on a camera. Listen to a sample before you record the whole thing. Make changes and listen again. Like any art, it is all about experience. An expert with budget level microphones could capture better audio than a novice with the most expensive equipment.
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