Microphone Types & Characteristics

What is a microphone?It’s a transducer that changes one form of energy (sound waves) into another (electrical signals or electric current)

It converts acoustic sound energy into electrical energy

(Your ear is a transducer too - it also converts sound waves into electrical impulses that are sent to the brain).

Acoustic energy is “converted” to an electrical charge that is amplified and converted back into acoustic energy.

Microphone TypesThere are three different types of microphone.

They differ in the way that they convert sound to electricity. The three types are:

Dynamic

Condenser

Ribbon

Dynamic Microphones

Dynamic microphones work on the electric generator principle

A diaphragm moves a coil of wire within a magnetic field.

Dynamic Microphone

When to use a Dynamic Mic

Great for live vocals

Great for high SPL (sound pressure level) instruments such as snare drums, kick drums, guitar and bass guitar amplifiers.

A very robust option both live and in the studio.

Good for loud rock vocalists.

Dynamic Pros & ConsPros Cons

• Tough

• Inexpensive

• “Gutsy” sound

• Can handle loud sounds

• Good for snares/kick drums/loud amps

& live vocals

• Operate well in different temperatures,

good for outside.

• Resistant to moisture so great onstage

• Lacks the frequency response of

condenser microphones

• Cannot be miniaturised.

Popular Dynamic Mics

Shure SM57 Good for instruments and vocals. Legends!

Shure SM58 Good for instruments and vocals. Legends!

AKG D112 Great on kick drums (Large diaphragm)

Condenser Microphones

Operate on the principle of measuring the change in electrical charge across a capacitor where one of the electrodes is a thin conductive membrane that flexes in response to sound pressure.

Condensers can have a much lighter diaphram and therefore are much more sensitive than dynamic microphones

Condenser Microphone

When to use a Condenser microphone

Vocals

Acoustic guitar

Orchestral recordings

For use on toms and for use as overhead mics on drums

Cello and upright bass (will give better low frequency reproduction on these instruments - ie pick up bass sounds well).

Condenser Pros and ConsPros Cons

• Switchable pickup patterns

• High sensitivity

• High frequency detail

• Flatter frequency response

• Delicate

• Expensive

• Requre phantom power or batteries

• May be affected by temperature and

humidity

Condenser MicrophonesAKG C414

Neumann U87

M-Audio Nova

Studio Projects C3 AKG C480

Neumann KM184

Phantom Power

Condenser microphones need power supplied

48V DC transmitted along the signal cores of a mic cable

Ribbon Microphones

A microphone where the sound capturing element is a thin metal ribbon suspended in a magnetic field.

When sound causes the ribbon to vibrate, a small electrical current is generated within the ribbon.

Very ‘natural’ sounding microphone.

Ribbon Microphone

When to use a Ribbon Microphone

Good for broadcasting - the speaking voice.

Not good for loud instruments

Pros & Cons of a Ribbon Microphone

Pros Cons

•Capable of high quality results in the mid to

high frquencies

• Very delicate.

• Not suitable for high SPL applications.

Such as close mic’ing amps and drums.

Microphone Chatacteristics

Transient

Frequency

Directional Response (polar pattern)

SPL Handling

Sensitivity

Transient Response

A transient is commonly defined as “an abrupt or sudden change in level”.

Transient Response refers to the ability of a microphone to respond to a rapidly changing sound wave” - Shure Microphone Techniques

A microphone’s ability to accurately capture these transients is known as transient response

Condensor microphones generally have a better transient response than dynamic mics.

Transient ResponseAs the diaphragm in a dynamic mic is relatively heavy, the transient response is not as accurate as a condenser mic.

(ie a dynamic mic does not pick up sound as quickly as a condenser microphone).

Frequency Response

Frequency response refers to the way a microphone responds to different frequencies.

It is a characteristic of all microphones that some frequencies are exaggerated and others are attenuated (reduced).

A frequency response which favours high frequencies means that the resulting audio output will sound more trebly than the original sound.

Frequency Response

Directional Response (polar pattern)

The pickup pattern is the area around the mic where sound can actually be “heard” by the microphone.

A mic’s directional response is key to it’s usage, not only in determining where it is most sensitive, but also where it rejects sounds most effectively.

Omni Polar PatternPicks up sound from all directions.

Good for ambient sound/audience and performers

Recording groups of musicians.

Cardioid Polar Pattern

Picks up sound only in front of the mic

Supercardioid Polar pattern

More directional at the front with a narrower pickup at the back.

Tightest pickup

Distance micing

Figure of 8

Picks up sound from front and back but not the sides.

Good for two singers on either side.

Picking up the main source & the reflection (room ambience)

SPL Handling

Ability to handle loud sound sources

Dynamic mics can handle louder sound than condensers

Sensitivity

Sensitivity is simply a measure of how much electrical signal comes out of the microphone for a given level of audio input.

The less sensitive a mic, the more amplification you need to get the sound up to a useful level.

Shure SM57 - Dynamic

Snares

Amps

Frequency Response: 40 to 15,000Hz

AKG D112 - Dynamic Mic

Large diaphragm

Kick Drums

Handles up to 160dBSPL

Bass amps

AKG C414Condenser

Switchable Polar Pattern

Good for vocals and instruments.

Good for close miking

Also good for distance mic’ing such as classical music or drum ambience mic’ing.

Neumann U87

Condenser

Smooth classic vocal sound

Good for vocals and instruments

Used for orchestral recordings

Record in MONO

When you record, open up an audio mono track

Gives you more control over the audio when mixing.

DO NOT record onto a stereo track

Stereo is used in location recording mostly.

You can make stereo recordings in the studio (such as X-Y or spaced pair techniques)

Record in Mono