P.A. and Sound Reinforcement Terminolgy
Mixer
The electronic box with multiple inputs and outputs that takes signals
from microphones and electronic instruments (keyboard, bass, guitar, etc.)
and mixes them before sending them to power amplifiers or recording
equipment.
Speaker Stack
Because it has to spread a lot of sound over a wide range of
frequencies, it usually consists of cabinets that house subwoofers,
midrange speakers, and high-frequency speakers. You typically see on
one on each side of the stage.
Power Amplifiers
These beefy boxes contain circuitry that takes the low-level signal
from a mixer and boost it before sending the amplified signal to
speakers.
Monitors
Special speaker cabinets are located onstage so that the performers can
hear themselves and hear each other better. In some cases, these are
replaced by in-ear monitors that look like hearing aids.
Microphone
A device to convert acoustic sound energy to an electrical signal that
can be amplified. The link between the singers and the P.A. system, as
well as the way acoustic instruments and some amplified instruments
have their sounds captured and sent to the mixer.
Microphone Stands
These metal stands aren't just for singers to lean on or swing around.
They're supposed to hold microphones so that the microphones are
pointed toward the sound sources that they're supposed to pick up and
send to the P.A. system.
Large glossaries of P.A. and Sound Reinforcement terms are available at: