Real World Digital Audio

Mic Type and Construction

Microphone types or models are families of microphones that share a means

of construction and accompanying acoustic characteristics. The two most

common types are dynamic and condenser mics, although ribbon mics are

popular for recording as well. Traditionally, dynamic mics have been more

affordable, but today many high-quality condenser mics compete even in

the sub-$200 range; ribbon mics almost always command a higher price.

Because different mic designs produce various trade-offs, there’s no perfect

mic: even beginners should consider assembling a small “mic cabinet” of

models for maximum flexibility and creative options. Typically, this would

include at least a matched pair for stereo recording and a combination of

condenser and dynamic mics. Even two or three good mics will provide

additional choices for recording.

Needless to say, this isn’t just “buying advice.” Once you have several

microphones to choose from, you’ll regularly select certain microphones

for different applications, so knowledge of mic types is critical to creating

the recording you want.

Tip: Starter mic ideas

A great recording can begin with relatively inexpensive mics; two matched dynamic

mics and a condenser mic would be a good starting point. Here are some typical

examples, although there are many options:

Dynamic:

Shure SM57 / 58 / Beta 58 ($80–150 street), Blue The Ball or USB-compati-

ble Blue Snowball ($100–150)—Ideal for drums, vocals, onstage

Condenser:

Røde NT-1A ($200, shown), Studio Projects C1 ($200)—Ideal for vocals,

instruments

Dynamic

Dynamic mics use a moving magnetic coil to produce voltage (Figure 6.5),

so they’re sometimes called moving-coil mics. They operate on the principle

that any coil moving perpendicular to a magnetic field will create current, a

process called electromagnetic induction. The fact that they require a physical

coil to be moved is their primary advantage and disadvantage: dynamics are

unusually resistant to air pressure and are the most rugged mics, but they’re

not as good at picking up high frequencies.

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If you want a mic that can take some physical abuse or record loud sources,

make sure you use a dynamic mic. You’ll find it’s invaluable for many other

recording applications, too, which is why you won’t find a pro studio in the

world without an SM57 on hand.

Genre-bending mics:

You can’t rely on rigid categories to understand micro-

phones, because engineers are always breaking the rules. Case in point: Blue makes

popular, powered dynamic mics like the USB-connected Snowball (pictured, courtesy

Blue Microphones), an exception to the “rule” that dynamics don’t need to be powered

(see sidebar “Phantom Power”, p. 167). By powering the mic, engineers are able to mix

desirable qualities of condensers and dynamics, and make a mic that can be used in

a wider variety of recording situations.

Figure 6.5

Inside the

dynamic capsule.

(Illustration cour-

tesy Shure, Inc.)

 A light, thin diaphragm (usually Mylar) is displaced by air

pressure created by sound waves.

 A coil of wire attached to the diaphragm moves as the

diaphragm moves.

 As the coil of wire moves it disrupts a fixed magnetic field,

generating current, which is fed out of the mic as output

signal.

Dynamic examples:

Shure SM57/58,

Sennheiser MD421 mk II

(shown at the bottom

of p. 164, courtesy

Sennheiser Electronic

Corporation)

Needs power?

No

Pros:

Rugged, wide

amplitude range, often

more affordable

Cons:

Not as good at

capturing high frequen-

cies, tend to “bias” low-

end, produce a weaker

signal

Best for:

General-

purpose recording, loud

recordings like drums

and guitar amps,

onstage applications

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