AUDIO SYSTEMS

IMPEDANCE Is a measure of resistance AND conductance Is broadly classifiable as – High (or unbalanced) – Low (or balanced)

High Impedance Has an unshielded conductor usually >5kΩ (5,000 Ohms) NEVER run more than 25’ of high impedance cable Very susceptible to outside electrical interference

Low Impedance Has two shielded conductors Is typically ≥50Ω and ≤600Ω – 150Ω, 250Ω, 300Ω, 600Ω Shield takes outside signals to ground

Impedance Matching Impedances MUST match within a range (high or low) Transformers may be used to match different impedances

MICROPHONES May be classified by Generating or pickup element Impedance Pickup pattern Use

Pickup/Generating Elements Ribbon or Velocity Dynamic (electret) Condenser Pressure Zone

Impedance High Low

Pickup Pattern Omnidirectional Cardioid Hypercardioid

Use Handheld Lavaliere Cordless – Body pack – Handheld Directional – Shotgun – parabolic