Audio Equipment and Microphones

Audio Interface

Connects ALL audio to DAW

Audio Interface Ports

Can vary in number of ports from 1-2 all the way up to more than 20 inputs

Audio Interface Inputs

Many will have a combination of inputs: Audio in (XLR or 1/4") and Digital I/O (ADAT)

Audio Interface Output

Output can range from 2 channels (stereo out) to 4 channels (Quad) to 6 channels for 5.1 out

Phantom Power

Many interfaces also have phantom power (48V) as well as pre-amps for microphones

Mic Pre-amp

Used to boost low-level signal from microphones

Built-in Pre-amps

Most consoles and interfaces will have a pre-amp built in

Separate Pre-amps

Separate pre-amps generally have superior frequency response

Mic and Pre-amp Selection

Engineers often pick mic and pre-amp to best suit the instrument/voice and mic

Pre-amp Capacity

Most pre-amps can handle 1-4 microphones; some as much as 8

Rack Mounted Pre-amps

Usually rack mounted - conceivably, a rack unit could be dedicated to pre-amps if you need to have multiple units

Audio Processing in Pre-amps

Some will have some audio processing abilities (EQ, effects)

Pre-amp Cost

They're not exactly cheap - ranges from ca. $200 -$5K

Graphic Equalizer

Basically a filter bank

Graphic Equalizer Function

Each fader controls a small range in the audio spectrum

Fader Adjustment

Fader is set to boost signal (above the "0" center line) or curtail it (below "0")

Limiter/Compressor

Often used in mixing to shape the sound

Dynamic Control

In recording, used often to prevent a signal overload

Compressor Function

Compressor decreases the dynamic range of the signal

Patch Bay

Allows the user to connect various devices (mics, instruments, effects, speakers, etc.) in one central location

Patch Bay Modes

Most have different modes to connect the front panel connectors to the rear connectors

Microphone Invention

Microphone invented by Johann Reis in 1861

Edison's Phonograph

Captured acoustic vibrations

Electrical Recording

Edison's Carbon Microphone used in the telephone

The Ribbon Mic

Classic mic introduced in the 1920s

Ribbon Mic Function

The Ribbon acts as a Transducer converting mechanical vibrations into an electrical signal

Condenser Mics

Two electrically charged plates: Diaphragm (moving) and Backplate (fixed)

Electret Condenser

Permanently polarized material (electret) that does not need phantom power

Neumann U 47

Telefunken Condenser Mic shown with VF - 14 tube amplifier costing $14K

Neumann U 87

Large dual-diaphragm capsule introduced in 1967, still in use as the U87A or U87Ai, original used two 22.5V batteries, new cost ca $3750