Microphones: Types, Patterns, and Selection

The Three Types

All microphones convert acoustic energy into electrical energy. They differ in mechanism — how the moving part generates the signal. That mechanism determines the mic’s character, its strengths, and what you can get away with.

Dynamic

A dynamic mic works like a speaker in reverse. A speaker is just an electromagnet connected to a cone — send some voltage into the magnet and you move the cone. Turns out the opposite is also true. If you move the cone, you generate a little current. A diaphragm is attached to a coil of wire that sits inside a magnetic field. Sound hits the diaphragm, the coil moves, and that motion generates a tiny electrical signal.

Dynamic mics are rugged. They handle high SPL (loud sounds) without breaking a sweat, they don’t need external power, and you can drop one on concrete and it’ll probably still work. That durability comes at a cost — they’re less sensitive to quiet sounds and subtle detail than condensers. They tend to have a focused, “right here” quality that cuts through a mix.

The Shure SM57 and SM58 are the most common microphones on the planet. An SM57 has been on every U.S. presidential lectern since Lyndon Johnson. They cost about a hundred dollars and they work on almost anything. If you’re starting out, start there.

Condenser

A condenser mic uses two charged plates — one fixed, one movable (the diaphragm). Sound moves the diaphragm, which changes the distance between the plates, which changes the capacitance, which creates a signal. Because the diaphragm doesn’t have to move a heavy coil, it responds faster and more accurately to transients and high frequencies.

Condensers are more sensitive and detailed than dynamics. The trade-off: they need phantom power — 48 volts sent from your interface or preamp through the XLR cable. (This is why phantom power exists. We covered the cable that delivers it in Chapter 3.) They’re also more fragile, more expensive, and more likely to pick up sounds you didn’t want.

Two subcategories:

• Large-diaphragm condensers (LDCs) — the classic studio vocal mic. Neumann U87, AKG C414, or any of a dozen excellent options under $300. Warm, detailed, flattering.
• Small-diaphragm condensers (SDCs) — pencil-shaped, accurate, neutral. Acoustic guitars, drum overheads, stereo pairs. AKG C451, Neumann KM184.

Ribbon

Technically, ribbon mics are a type of dynamic microphone — they generate signal through electromagnetic induction, same as a moving-coil dynamic. But they behave so differently in practice that they’re treated as their own category.

A thin corrugated metal ribbon suspended between two magnets. Sound moves the ribbon. That’s the whole design — no coil, no charged plates, no electronics. Just a strip of metal in a magnetic field.

Ribbons sound warm and smooth. They naturally roll off high frequencies, which makes them flattering on harsh sources — guitar cabs, brass, bright or sibilant vocalists. They capture transients beautifully. Historically they were fragile and expensive; modern ribbons are more durable, but you still don’t blow into one to check if it’s on. And never send phantom power to a passive ribbon mic unless it’s explicitly designed for it — the voltage can stretch or destroy the ribbon element. It’s important that everything be connected the right way, because if not, particularly with something fragile like a ribbon mic, the results can be catastrophic.

Other Microphone Types

Beyond the three main families, you’ll occasionally encounter piezo and contact microphones, which detect vibrations through a surface rather than through the air — useful for amplifying acoustic instruments or capturing unconventional sound sources. Carbon microphones were the standard in early telephones but are now museum pieces. And yes, laser microphones exist — they measure vibrations on a remote surface using a laser beam. You won’t find one in a studio, but they’re worth knowing about if only because they demonstrate how broad the concept of transduction really is.

Polar Patterns

A mic’s polar pattern describes where it listens — which directions it picks up sound, and which directions it rejects.

Cardioid — heart-shaped. Picks up sound from the front, rejects the rear. The default for most recording and all live sound. If you only know one pattern, this is it.

Omnidirectional — picks up equally from all directions. No rear rejection, but also no proximity effect (the bass boost you get when a source is close to a directional mic). Good for room sound, ambience, and situations where you want the natural space.

Subcardioid (wide cardioid) picks up mostly from the front but with significantly more rear sensitivity than a standard cardioid. It’s less common on studio microphones, but it shows up on measurement mics and some specialty models. Think of it as the halfway point between omni and cardioid.

Figure-8 (bidirectional) — picks up front and back, rejects the sides. All ribbon mics are naturally figure-8 because the ribbon is open on both sides. This pattern is essential for mid/side recording (Chapter 9).

Supercardioid / Hypercardioid — tighter front pickup than cardioid, but with a small lobe of sensitivity at the rear. More isolation from the sides, at the cost of needing to watch what’s behind the mic.

Some condenser mics have switchable patterns — cardioid, omni, figure-8, and positions in between. These use dual-diaphragm capsules and are among the most versatile mics you can own.

Choosing a Microphone

There’s no “best” mic. There’s only the right mic for this source, in this room, right now. A few starting points that have worked for decades:

• Vocals: Large-diaphragm condenser is the default. But a dynamic like the SM7B works great for loud singers or untreated rooms (less sensitive = picks up less room noise). A ribbon can be magic on the right voice.
• Guitar amp: SM57 pointed at the speaker cone. That combination has produced more recorded guitar than any other. Add a condenser or ribbon a few feet back for room character.
• Acoustic guitar: Small-diaphragm condenser aimed roughly at the 12th fret area. Pointing at the sound hole gets you boom, not tone.
• Drums: Dynamics on close mics (kick, snare, toms), condensers on overheads and rooms.

But the real skill isn’t memorizing these charts. It’s listening with one ear. Close one ear with your hand and walk around the sound source. Move your head until you find the spot where it sounds best — fullest, most balanced, most like the instrument is supposed to sound. That’s where the mic goes. The mic hears roughly what one ear hears. Trust your ear, then verify with the recording.

What to Practice

1. Listen to your mics. Set up whatever microphones you own on the same source — your voice, a guitar, a hand clap. Record each one. Don’t EQ or process. Listen to the raw recordings back to back and notice the differences in tone, detail, and room pickup.
2. Find the spot. Close one ear and walk around an instrument while someone plays. Find the sweet spot. Put a mic there. Record it. Move the mic six inches in any direction and record again. Compare.
3. Test your polar patterns. If you have a cardioid mic, set it up and play music from a speaker. Walk a circle around the mic. Listen to how the sound changes as you move from front to side to rear. That’s the polar pattern in action.
4. Read the spec sheet. Pick one mic you own and find the frequency response chart online. See where it peaks and dips. Now listen to a recording through that mic — can you hear the character the chart describes?