Microphone Basics

If you’re looking to start podcasting, there are a few factors to take into consideration when selecting and positioning your microphone. While there are many terms and techniques that may be new to you, there are a few that you should know and understand when designing your recording setup:

Pickup/Polar Pattern

An important characteristic of any microphone is its directionality, also referred to as the pickup pattern or polar pattern. There are three basic patterns that describe the way most microphones are designed: unidirectional, omnidirectional and bidirectional (figure-8). Each of these patterns have distinct pickup characteristics with respect to the sensitivity and frequency response to sounds arriving from different directions. Some microphones have a single pickup pattern (C01U Pro, Q2U, Meteor Mic), while others have multiple patterns (C03U, Go Mic,). The following section addresses some of the features of each pattern to help you choose the best microphone for your application.

Unidirectional

A unidirectional microphone captures sound predominantly from one direction. Cardioid is the most widely used unidirectional pickup pattern for studio and live miking applications .It captures sound in front of the microphone, is less sensitive on the sides and rejects sound from the rear. This allows for better separation and picks up more of the performer’s voice in relation to the sound of the room. Furthermore, there are two common variations of the cardioid pattern: supercardioid and hypercardioid. Supercardioid is similar to cardioid, but has a narrower pickup area in front of the microphone, greater side-to-side rejection and a small pickup area in the rear of the microphone. Hypercardioid offers even more side-to-side rejection with a very narrow front pick area, and a tail off the back that picks up sound directly behind the microphone. While a unidirectional microphone is the best choice when looking to avoid picking up ambient room sounds, the sound characteristic changes if you move off-axis—the high frequency response will decrease.

Omnidirectional

An omnidirectional pickup pattern captures sound from all directions (including off-axis) with an even frequency response, which makes it resistant to the phenomenon known as proximity effect. It captures a greater amount of ambient sound than the other pickup patterns, thus more of a room’s sound characteristics can be expected on these recordings as opposed to those made with directional microphones. The omnidirectional setting is great for recording ensemble performances, including vocalists, as well as brass, woodwind and other instrumental groups, by having the performers face each other in a circle around the microphone. Typically, to select the omnidirectional pickup pattern, set the pattern selection switch to the left position, or wherever indicated by the circle icon.

Bidirectional (figure-8)

A bidirectional pickup pattern captures sound directly in front and back of the microphone while rejecting sound on the left and right sides, and has minimal off-axis frequency response deterioration. It’s very useful in a variety of stereo microphone techniques. The figure-8 pattern can be used to simultaneously capture two instruments or vocalists by positioning the microphone directly between them, so one is playing into the front of the microphone and the other, into the rear. Typically, to select figure-8 pickup pattern, set the pattern selection switch to the right position, or wherever indicated “8” icon.

Microphone Placement

In order to maximize the sound quality of your recording, you should pay careful attention to the placement of the microphone and how it is positioned in relation to the performer. In order to get the best frequency response, start by pointing the microphone directly on axis to the sound source. From there, you can change the desired sound characteristics that the microphone picks up by changing the position of the microphone. Rotating the microphone away (off-axis) from the sound source will decrease its sensitivity to higher frequencies. Experimentation is the best way to find out what sounds best for your recordings.When first setting up to record, place the microphone directly in front of the performer so that the grille is 6–24” away. If using a cardioid pickup pattern, the closer the performer moves to the microphone, the more the bass (or low frequency) response increases due to the phenomenon known as “proximity effect”. As the vocalist moves away from the microphone, the tone will become more natural as the low frequencies roll off. To achieve the fullest sound, the performer should aim the microphone centerline towards their mouth. If some consonants such as “P”, “B” and “S” seem to jump up in level, rotate the microphone slightly away from the artist so that sound arrives at the microphone slightly off-center.If recording multiple people, it’s best to use an omnidirectional or figure-8 polar pattern. These pickup patterns allow you to capture audio from around the microphone.Place the microphone equidistant from the performers. To minimize ambient or external noise, have the performers as close to the microphone(s) as possible and adjust the mic gain to pick up their voice at a level void of any overload or distortion.

Shockmount

To isolate your microphone from external vibrations and prevent unwanted noises that are transmitted through the stand to the microphone, it’s recommended to mount your microphone in a shockmount. Samson’s SP01 Spider Shockmount is an excellent option that will decouple your microphone from its stand or table.

Pop Filter

P-Pops are those annoying sounds that you can get when a microphone diaphragm is blasted with air from certain plosive consonants like hard “P” and “B” sounds. These P-Pops overload the input of the microphone and cause clipping, while adding distortion to your recording. There are a few ways to deal with this problem. The best solution is to use a pop filter such as Samson’s PS01 to reduce the effects of these blasts of air when speakers produce these hard consonant sounds. A pop filter also helps protect the microphone element from moisture. Some famous engineers have relied on an old nylon stocking over a bent clothes hanger, which actually works very well. You can also try placing the microphone slightly off axis (on a slight angle) from the speaker. This technique can often solve the problem without using pop filter.