GearCast - 5 Essential Tips for Choosing the Right Microphone

With more microphones available than ever before, at more price points than ever before, it can be confusing to choose the right mic. Fortunately, there are some mic characteristics that are universally important, and if you know these, you’re a long way toward choosing the right mic for your application.

1. Condenser mics are most popular for the studio, and dynamic mics for live performance.

Dynamic mics can handle high SPLs, are rugged, tend to be less expensive than other types (all things being equal), and don’t require the +48V phantom powerDefinition:
A source of power for a microphone (usually condenser) that travels to the microphone over the microphone's cable. There are different voltage standards and requirements for different microphones, but the most common standard is 48 Volts. It derives its name because there is no visible power cable. required by condenserDefinition:
An archaic term for Capacitor. mics. However, their transient responseDefinition:
The ability for a piece of equipment to follow a fast-rising waveform, and reproduce it accurately. and high-frequency responseDefinition:
The range of frequencies that an audio, video or data device can pass. isn’t as good as condenser mics, which is why the latter are favored in the studio. High-quality condenser mics can also be expensive. However, there are plenty of exceptions to the “dynamic mics live, condenser mics studio” thinking: Shure’s SM57 dynamic mic (Fig. 1) is a go-to studio mic for guitar amps yet costs under $100, while DPA’s 4018VL Condenser Mic is designed specifically for on-stage use.

2. Choose the appropriate polar pattern for your application.

A mic’s polar patternDefinition:
A graphic representation illustrating in positional degrees the sensitivity or radiation of a microphone, speaker, or antenna. defines how it picks up sound. For vocalists on stage, a cardioidDefinition:
A microphone's heart-shaped directional pickup pattern. response rejects sound from the mic’s rear, which helps reduce the possibility of feedbackDefinition:
1. A squealing, chirping, or ringing sound when a microphone feeding a loudspeaker picks up audio from that loudspeaker. Also called howlround.  2. The state where a device's output connects back to the input.. A supercardioidDefinition:
A unidirectional microphone polar pattern that is narrower than a cardioid mic, but wider than a hypercardioid mic. response is even more focused. An omnidirectionalDefinition:
A pattern describing a microphone, radio antenna, or loudspeaker that radiates or picks up in all directions equally. mic picks up all sounds evenly and has the most balanced sound, which makes it good for recording room sounds, conferences, and group vocals. A ribbon microphoneDefinition:
A microphone technology that incorporates an extremely thin rectangular aluminum or aluminized membrane in a strong magnetic field. It's natural polar pattern is figure-8. See Figure-8. Also called Velocity Microphone., like the Royer R121 (Fig. 2), has a bi-directionalDefinition:
A microphone or speaker that operates in two directions simultaneously, with one side "in phase" and the other 180-degrees out of phase. Also called "figure-8." (also called Figure-8) response.

Ribbon mics accept sounds from the front and back but have almost perfect rejection from the sides. As with all mics, often what a mic doesn’t pick up is as important as what it does pick up—for example with a drum kit, a ribbon mic can pick up specific drum sounds while rejecting the rest of the kit.

3. The diaphragm size matters.

Both condenser and dynamic mics offer large, small, or medium diaphragms—the part of the mic that air hits to help create an electrical signal. Large-diaphragmDefinition:
The moving portion of a microphone that transforms sound waves into motion that can ultimately produce electrical waves. mics, like the MXL-990XL extra-large diaphragm condenser mic (Fig. 3) are more sensitive to low levels, and less sensitive to high frequencies. They’re good for vocals (except for “screamers”) and recording softer sounds like room sounds, nylon-string guitars, ukuleles, and environmental sounds.

Small-diaphragm mics are less sensitive to low levels, can handle higher levels, and are more sensitive to high frequencies. Small-diaphragm condenser mics are excellent choices for acoustic percussion instruments, which also takes advantage of the condenser mic’s inherent fast transient response.

4. Accessories are important.

Wind screens and pop filters not only minimize plosives but help keep “mouth spray” out of the microphone. You’ll also want a solid mic stand, and shockmount to isolate the mic from vibrations that come up through the stand. Good mic cables are important to avoid noise pickupDefinition:
1. Transducer attached to a musical instrument that converts mechanical vibrations into an electrical signal for recording or amplification.  2. The part of a phonograph that translates mechanical motion from grooves into electrical signals for subsequent amplification., and you also want quality mic preamps that, with condenser mics, can produce a full +48V of phantom power (not all do, even though the front-panel silkscreen may say “+48V”). Also, on-location and field recording present special challenges, in particular, wind noise and handling noiseDefinition:
A mechanical noise picked up by a microphone or pickup from being held or touched.. Rycote’s 089101 Cyclone Windshield Kit (Fig. 4) is one of the most effective options available for minimizing noise issues while retaining microphone transparency.

5. Don’t overlook the rich possibilities of stereo miking techniques.

If one mic is good... two mics are better! Okay, not always—stereo only matters with vocals if you have a two-headed vocalist. But for recording ensembles, acoustic instruments, room sounds, and the like, there are many possible methods of stereoDefinition:
A two channel signal simulating a sound space, typically played through two speakers. miking. The most common are XY, A-B spaced pairDefinition:
Spacing two microphones 3 to 10 feet apart to create a stereo image., ORTFDefinition:
(Office de Radiodiffusion Télévision Française) A stereo microphone array based on using a pair of small-diaphragm cardioid mics, spaced 17 mm apart and at a 110 degree angle to each other., Mid-SideDefinition:
Mid-Side processing separates a stereo field into a mid channel (the center of the stereo signal, or what the two channels have in common) and the sides (the right and left components that don't have anything in common). The balance of the mid and side signals can be controlled electronically, before or after recording, prior to combining back into stereo., and Blumlein (for a description of these and how to set them up, see Phil O’Keefe’s book, “Microphones for the Recording Musician,” published by Hal Leonard). For stereo miking, mic bars like the On-Stage MY800 (Fig. 5) are essential for holding two mics in a stereo configuration.