Sound Systems:
Purpose - reinforce the sound.
Mixer:
Purpose - "Mixes" the sound, receives signals from microphones, instruments, etc.
Process the signal for level and tone which then goes to the outputs.
Online Samples
Beatbox DJ Mixer
Online Mixer
Types:
Powered - Built in Amplifier
Unpowered - Amp and Mixer are separate units
Parts of the Mixer:
Channel Strip
Gain
EQ
Pan
Monitors
Mains
Signal Flow