Why is Proper Mic Placement Important?
When recording audio or taking part in a voice conference, the position of your microphone can be one of the most important factors to your overall sound quality. Poor mic placement can result in the appearance of breathing, occasional or complete dropout of volume, and distorted or overdriven audio. If you’re recording a podcast, poor mic placement may not present itself until you review a completed segment after the fact, resulting in a need to reshoot.
It’s important to note here that not every condenser microphone focuses the same way. Some require you to aim the tip of the microphone at the subject while others are attuned so you talk into the side of them. These microphones are typically referred to as “side address” or “side fire.” Make sure you’re using your particular microphone the right way to avoid a muffled sound caused by your subject talking towards the back or side of the pickup.
If you’re working with a lavaliere-style microphone, you’ll want to make sure it’s clipped somewhere that is less prone to movement and friction. Placing it on a loose collar may seem like a great idea, but if that collar shifts as the subject moves and gestures, it can cause a lot of noise on your track. Also, you want to avoid holding it if there’s an option. It’s easy to treat a lavaliere microphone as a regular mic and hold it extremely close to your mouth. This is much closer than the mic is attuned for, and can overdrive the sound if the levels aren’t preset correctly. Any time you’re doing serious audio, you want to have the most consistent possible mic placement from start to finish. Lavaliere microphones tend to be attuned for stationary placement on the person.
It’s also a good idea to bring a black necklace cord with you when going out on the field. If you need to mic a subject with a lavaliere that isn’t wearing something that plays well with a clipped mic, you can clip it to the cord and have them wear that for more consistent audio than a hand-held lavaliere can provide.
Handheld dynamic microphones are typically made to take a beating. They’re designed to be held by hand or by a mic stand, moved around during a performance, and work at variable distances very well. Dynamic microphones are often used by on-stage performers and on-air personalities reporting from the scene of an event. They’re also greatly preferred for interviews where they may be passed between various people. A large condenser microphone generally doesn’t play as well with vibrations and movements. Dynamic microphones are generally flexible in positioning, with the best results coming from a space of between six and twelve inches from a subject’s mouth. You can up the gain for a longer distance, but you’re also letting in more of the background hiss when you do so. Too little gain in a noisy environment can make it difficult to hear the subject at all. As with any microphone, you should avoid placing it directly in front of someone’s mouth unless you’re in an environment that is so noisy that lowering the gain is an absolute must.
Shotgun microphones can usually be found in controlled recording rooms or mounted on top of camcorders. These microphones are attuned to capturing sound from greater distances in a specific direction. Just as the name suggests, you want to aim a shotgun microphone directly at your subject. They are commonly used in situations where a specific subject needs to be heard in a noisy environment. Unlike omnidirectional microphones, shotgun mics perform poorly when receiving audio from the side and back. You’ll receive the best results when using them with subjects or a subject is positioned directly in front of them at a distance.
Headset microphones are generally unidirectional (like the shotgun) with a much smaller field of pickup. It’s very easy to forget proper mic placement when using a headset, as our first inclination is generally to place it over the mouth. Unless you’re using one of those massive sports broadcaster headsets that are made for picking up a specific subject in an extremely loud environment, there’s a good chance that you’re going to be breathing all over the track if you do this. Position the microphone just past the corner of your mouth, near your cheek. This will avoid breathing sounds (check to see if you can feel air from your nose as well) during recording. Also, try to avoid any headset with a loose or easily moved arm. This can cause vibrational distortion during recording.
Record a test track with everyone prior to recording the actual presentation. If you intend to move microphones during the actual presentation, do so on the test recording. Pay close attention to anything that appears off and instruct everyone to keep mic and body positions as stationary as possible.
When people talk, they tend to move around. Some microphones (especially condenser and lavaliere) are set to pick up sound at a specific distance. While you can simply up the gain and capture someone across the room if you want to, this introduces a significant risk of background noise ruining an otherwise clear piece of audio. Any time someone has their head turned away from the microphone, the sound level and gain will drop off significantly. You may not notice it during recording, but after the fact you can hear exactly when someone turns their head.
Distance is everything. Make sure you’re keeping the microphone at the correct distance based on the mic specs and gain levels. The results can be dramatically better with even the slightest change in distancing. Closer is not always better.