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 power required by condenser mics. However, their transient response and high-frequency response 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 is a condenser mic that’s designed specifically for on-stage use.
2. Choose the appropriate polar pattern for your application.
A mic’s polar pattern defines how it picks up sound. For vocalists on stage, a cardioid response rejects sound from the mic’s rear, which helps reduce the possibility of feedback. A supercardioid response is even more focused. An omnidirectional 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 microphone, like the Royer R121 (Fig. 2), has a bi-directional (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-diaphragm 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 pickup, 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 noise. 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 stereo miking. The most common are XY, A-B spaced pair, ORTF, Mid-Side, 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.