Microphone CapSULE Types

Terminology

Mic body
Everything below the capsule
Capsule
Head or pickup area that contains the element
(Transducing) Element
The actual tranducer system
Diaphragm
The part of the element that physically responds to air pressure.  A very thin delicate membrane that can be either small (1/2") or large (1") in size

Characteristics

The mic matters!  Arguably more than any other tool, the microphone is responsible for character of the sound. All other points in the chain derive their results from it.

 

  • Amplitude Sensitivity = Transient Response
  • Frequency Response
  • Directionality

 

Every mic is different– You have to know them

Transient

A high amplitude, short ​duration attack at the beginning of the envelope.

Lots of Transients 

Few Transients

(tabla)

(tamboura)

Faster Transient Response

Slower Transient Response

Faster Transient Response

Slower Transient Response

Transient Response

How fast and accurately the diaphragm reacts to transients

Frequency

More Flat

Less Flat

Audio Technica 3032

Shure SM58

Frequency Response

RIBBON

Principle of Magnetic Induction:

When a piece of metal moves in a magnetic field, it generates a voltage (electricity).

TRANSIENT RESPONSE

Ribbon

(Royer R121)

Less high frequency detail

FREQUENCY RESPONSE

Ribbon

(RCA 77DX)

Because they have these characteristics...

  • Increased low-mid frequency response
  • Decreased high frequency response
  • Slow transient response
  • Somewhat fragile

...Ribbon mics are often used:

  • On quieter high frequency sources that need fullness
    (harp, mandolin, violin)
  • On louder high frequency sources that need controlling
    (horns, some guitar amps
    )
  • On sources that have sharp transients in need of taming
  • Mostly in the studio
    (less in live or field recording)

Royer R121

Cascade

Fat Head II

DYNAMIC

Principle of Magnetic Induction:

When a piece of metal moves in a magnetic field, it generates a voltage (electricity).

These are sometimes called "moving-coil mics."

TRANSIENT RESPONSE

Ribbon

(Royer R121)

Dynamic

(Shure SM58)

FREQUENCY RESPONSE

Ribbon

(RCA 77DX)

Condenser
(AT 3032)

Dynamic

(Shure SM58)

Because they have these characteristics...

  • Moderately restricted high and low frequency response (but still covers key ranges)
  • Moderately slow transient response & sensitivity
  • Very sturdy

...Dynamic mics are often used:

  • On sources that don't need too much detail across the full frequency spectrum
    (kick drum, toms)
  • Close on very loud sources
    (snare drum, guitar amps)
  • In live performance, as well studio in some cases

Shure SM57

Sennheiser

MD 421

CONDENSER

Principle of Electrostatic Induction:

Every object has charged atoms.  When an uncharged object (equal + and – atoms) gets near an electrically conductive object (metal), electrons move between them, causing a flow of electricity.

The static built-up on the cat's fur makes it an electrically charged object (!).  The atoms in the uncharged styrofoam want to move towards the conductive cat, generating a voltage as they do it.

The cat appears unimpressed with this.

This basically how a capacitor works, so sometimes they are called "capacitor mics."

  • Most often supplied by the mixer channel; sometimes with a battery, or a separate power supply (for tube mics).
  • Turning +48v on/off produces a very large spike in the channel– Keep the channel CUT when doing it.
  • Turn +48v on only AFTER the mic is plugged in.  

CONDENSER MICS WILL NOT FUNCTION WITHOUT PHANTOM POWER!

To charge the capsule, condensers require a voltage sent down the mic cable.  This charge is called phantom power.  Phantom Power is often abbreviated as "+48v" (so memorize it)

Phantom Power (+48v)

TRANSIENT RESPONSE

Ribbon

(Royer R121)

Dynamic

(Shure SM58)

Condenser

(Neumann TLM 103)

Most high frequency detail

FREQUENCY RESPONSE

Condenser
(Audio Technica 3032)

Dynamic

(Shure SM58)

Because they have these characteristics...

  • Full-range frequency response
  • Very fast transient response & sensitivity
  • More fragile than a dynamic mic

...Condenser mics are often used:

  • On sources benefit from the full frequency spectrum (drum overheads, rooms, piano)
  • On sources with detail and nuance in their transients (acoustic guitar, voice)
  • In the studio and in the field, and sometimes in performance

Mojave

MA-100

Neumann

TLM 102

DIAPHRAGM SIZE

Mic diaphragms are different sizes (generally 1/4"–1"), and this has an effect on the characteristics of the mic.

 

This distinction in diaphragm size is most useful when describing condensers, although dynamic mics also have a diaphragm.

 

Regardless of diaphragm size, both mics still use the same operational principles.

Mojave

MA-100

Neumann

TLM 102

SMALL DIAPHRAGM CONDENSERS

Neumann

TLM 102

Neumann

TLM 102

LARGE DIAPHRAGM CONDENSERS

Audio Technica

4050

Manufacturer logo is always the front

  • Have a diaphragm of 1/4"–1/2"
  • Have a flatter frequency response (especially highs)
  • Give faster transient response
  • Have more accurate directional patterns
  • Are smaller and lighter 

Small Diaphragms...

  • Have a diaphragm of 1/2"–1"
  • Have a less-flat frequency 
  • Give a slightly slower transient response
  • Have a less-accurate directional pattern at high frequencies
  • Are bulkier and heavier 

Large Diaphragms...

  • Room Mics
  • Drum Overheads
  • Piano
  • Acoustic Guitar

Small Diaphragms...

  • Often preferred for close-miking
  • Voice
  • Strings & Woodwinds
  • Piano
  • Acoustic Guitar

Large Diaphragms...

These are very general guidelines.  Sometimes the difference between choosing a large or small diaphragm is obvious, and sometimes it's subtle.   

COMPARISONS

There are no "good" and "bad" mics– Only the right mic for the right job.  Choose purposefully!

TRANSIENT RESPONSE

Ribbon

(Royer R121)

Dynamic

(Shure SM58)

Condenser

(Neumann TLM 103)

FREQUENCY RESPONSE

Condenser
(Audio Technica 3032)

Dynamic

(Shure SM58)

Ribbon
(RCA 77DX)

Neumann

TLM 102

SAFETY

This is one area where there is real potential danger of damage to people and things!

MIC MOUNTING

This is one area where there is real potential danger of damage to people and things!

PEOPLE

It is your #1 responsibility as an engineer to be in control of all listening levels at all times– Even you're not in the control room.

  • The control room level is always down when going out to move a mic.
  • The DIM and CUT buttons in the control room monitoring section are your friends.
  • Mics fall, get hit, short circuit– These can be extremely loud events.  Mute mics that are being moved.

PEOPLE

Take special care with phantom power!

  • +48v is never on when plugging or unplugging a mic.
  • The channel is always CUT when +48v is switched on/off.  

Not being careful here is the fastest way to lose the confidence and trust of people you're working with.

THINGS

Set up every mic correctly:

  • Solid stand– on the ground, center post raised
  • Mic mounted securely, and not prone to slipping out of shockmount or clip
  • Won't be in a performer's way or hit
  • No stretched cables, and cable runs are the least intrusive they can be
  • Gaff tape where needed (but don't over-do it)

THINGS

Mics & speakers can damage easily:

  • DO NOT BLOW IN A MIC!
  • DO NOT BANG ON IT WITH YOUR HAND (OR ANYTHING ELSE)!
  • Check a mic by lightly scratching the grill with your finger.
  • Do not turn +48v on a ribbon mic.
  • Use a pop filter on every voice recording, and when using a ribbon on a very loud source.
  • When assembling a mic, think about where it goes if it falls...
  • If you drop a mic:
    Note it and test at the end of the session.  If there is some doubt it is working, mark it and alert the authorities.  Pretending it didn't happen is worse than dealing with it.

See Also:

Mic Setup class exercise checklist

 

New Mic Setup videos (Reading at the bottom of the "Capsules" topic page)

Microphone Capsules

By Brian

Microphone Capsules

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