Choosing the Right Microphone
In the recording studio, choosing the right microphone to capture an instrument or vocal is a key to creating a high-quality recording. At the same time, microphone selection is a subjective thing because there may be more than one “right answer.” In fact, this decision is a huge part of how audio engineers come up with their “signature” sound in the studio, which is why every engineer approaches the process a little differently, and why each one has different preferences when it comes to microphone selection and placement.
Because this is such a nuanced part of the recording process, it’s not a simple thing to tell you which microphone to use in a particular situation. All we can do here is tell you what is commonly used; your mentor may have techniques and ideas that vary a bit from what we say here. The key is to choosing the right microphone is to find out for yourself the microphones that work best in certain situations, and this comes mostly through practice and by watching your mentor. Even so, the following overview should give you an idea of the kinds of microphones you’re likely to find in the studio, and how they’re most commonly used.
DIFFERENT MICROPHONE TYPES
There are many different types of microphones, but the ones you’re most likely to encounter in the studio are condenser mics and dynamic mics. Condenser microphones require phantom power in order to operate, and they tend to be more sensitive and detailed in picking up sound (also more fragile). Dynamic microphones are of a simpler and more rugged design, and are considered good all-around workhorses in the studio, great for picking up louder sounds or for proximity miking.
MICROPHONE PICKUP PATTERNS
As if microphone design weren’t enough to deal with, microphones are also described by the area around them where they are sensitive to sound—their pickup pattern. Here are the most common types:
- Cardioid—picks up sound from the front and sides in the shape of a heart
- Bi-directional (or figure-8)—most sensitive to sound from the front and back, rejecting sound from the sides
- Omnidirectional—picks up sound in a 360-degree radius
MICROPHONE SELECTION TIPS
In general, microphones are chosen based on what you’re trying to record, and often multiple microphones are used to pick up different parts of the sound in the room (for example, miking a drum set can involve a dozen or more microphones to pick up individual drums/cymbals as well as ambient room noise to add to the mix). Here’s a basic guide to choosing the right microphone for what you’re trying to capture.
- For louder sounds and voices—Dynamic microphones are the usual choice for high-volume sounds, especially at close range. (In fact, some condenser mike elements are too fragile and will break if incoming sound pressure levels are too high.) Examples might include miking snare drums, rock vocals or electric guitar amplifiers.
- For proximity (close) miking—Dynamic microphones are also good for close-miking, specifically because they tend to isolate the sound from other sounds in the room. For even more isolation, choose a dynamic mike with a tighter cardioid pattern that captures mainly on-axis sounds.
- For softer acoustic instruments with wider dynamic ranges—Condenser mics can be excellent tools for picking up the dynamics and nuances of acoustic instruments, especially woodwinds, strings and acoustic guitars—and equally so for quieter, more expressive vocals.
- For ambient miking—To capture the overall collective sound in a live room, consider using one or more condenser microphones a short distance from the instrument or ensemble, either in a wide cardioid or omnidirectional pattern. To capture even more of the ambient or reflective noise, consider omnis in the further reaches of the room.
- For stereo miking—Condensers are usually best for capturing stereo signals. There are a variety of placement techniques to accomplish this, and they can include various combinations of cardioid, omnidirectional and bi-directional microphones. (Your mentor will likely have his/her own preferences here.)
As you practice with microphone placement, eventually you’ll land on certain combinations and placement methods that you like better than others as you develop into a professional audio engineer. Beyond the guidelines above, ultimately the choosing the best microphone comes down to what you’re trying to capture and what gives you the best sound.