Audio Recording Scott Barnes, Sanford Media Center - Gorgas Library

Microphone Placement

Knowing how your microphone picks up sound is important when deciding the best placement for the mic. Every mic has areas that it is more sensitive and less sensitive this map of sensitivity is called the pick-up pattern.

The three most common pick-up patterns that you are likely to run into are cardioid, figure 8, and omnidirectional. Cardioid microphones have a heart-shaped pattern with the front of the mic being more sensitive than the sides and the rear of the mic being the least sensitive. Figure 8 has areas of sensitivity at the front and back and reduces sensitivity as you approach the sides. Omnidirectional microphones have equal sensitivity around the entire microphone. You will want your sound source to be in the sensitive areas and any noise sources to be in rejection areas. To see what is microphones or recording devices are available for reservation and check out from the Library click the button below to take you to the Equipment Reservation Page

Sound Source Distance

With multiple sound sources (like with multiple people), distance adjustment is a little trickier. You want to adjust distances so that everything is recorded at about the same level. For example, if you're recording 2 speakers with a "figure 8" mic, a quieter person should be closer to the mic and the louder person should be a little farther. It's best to experiment for a few minutes to get the levels right before you start recording.

Another thing to be aware of and avoid, especially when recording vocals, is "plosives". Plosives are the harsh sound created from jets of air that are released from our mouths when using words with p's and q's. If you place your hand in front of your mouth and say "Peter piper picked a peck of pickled peppers" you will feel the jets of air hitting your hand. To reduce this effect a barrier is placed in between your mouth and the mic to either diffuse that jet of air or redirect it. This is called a pop filter. It is best to use material that is specially constructed to do this. But in a pinch hosiery or dress sock stretched over a wire hanger could be effective.

Recording Space

Next to getting the microphone close to your audio source, the most influential part of how your audio will sound is the space you are recording in. Ideally, this will be in a space that is treated with sound damping material. Like the Whisper Booths or The Studio Space in the Library at Sanford Media Center.

This may not always be possible. The first thing to do when choosing a place to record is to "listen". Just stop and listen to the environment around you. Do you hear things that can be turned off or unplugged for a short time while you record like air-conditioner or computer equipment? Do you hear the hum of electronics or slight rumble of street sounds that could be placed on the side of the microphone that isn't as sensitive? Also look around. Do you see a lot of hard surfaces? Hard surfaces reflect sound they should be avoided. Look for places with soft absorbent material like a walk-in closet. Or better yet build a pillow fort! No, seriously it helps.

Setting Audio Levels and Avoid Clipping

We are at the last part of setting up your recording. Most audio recording software is going to include a way to meter your audio's intensity often called Levels. In most programs this takes the form of a bar meter with colors that go from green to yellow to red. Avoid Red. This will cause "clipping" an undesirable form of distortion that doesn't sound good and can't be fixed in post. You should be shooting for the green and yellow regions or -6 if you don't have colors and just numbers. Here are some examples of good levels readings.