Sound Reinforcement Final

Portability ____ a primary concern for a sound system

Is or Is NOT

is NOT

Inverse square law

For every doubling of distance from a sound source, the intensity of a sound is reduced by four times it’s strength

Front of House (FOH)

term used to refer to the equipment or resources whose primary function is to provide audio coverage to main audience area

Diffusion

when the energy of a sound is propagated in many directions by an irregularly shaped object

Diffraction

change of direction of travel of sound waves caused by the interaction with an object

Reflection

the striking of a sound against a large flat object that propagates the energy at an angle equal to the angle of incidence

Early reflections

sounds that arrive within the first 80ms of the direct sound and add to the perceived loudness of the sound (when referring to reverberation)

Energy absorbed by acoustic panels is released as

heat

Pink Noise

type of noise signal that is equal energy per octave, most commonly used to assess speaker performance

Power Alley

The line between two speakers where both are in phase

Phantom Power 48 volts of power is supplied through the mic cable on pins…

• 1 & 2

• 1 & 3

• 2 & 3

2 & 3

Proximity Effect

An increase in the low frequency response of a microphone as a user moves very close to the diaphragm

Frequency range of a microphone describes…

The highest and lowest frequencies a microphone responds to

Frequency response graph shows…

How sensitive a mic is at different frequencies

A low impedance microphone is less than ___ Ω

600 Ω

The sensitivity of a microphone directly relates to the

mass of its diaphragm

Monitor world

the location from which the speakers located on the stage for the musicians is mixed

Two most common types of mics in live sound

Dynamic and condenser

Diversity is used to prevent dropouts caused by ____ _____ at the antennas when using wireless microphones

radio cancelations

Sensitivity rating of a mic is related to the…

mass of the diaphragm

Impedance

the total opposition that an electronic device gives to alternating currentQ

Which type of mic requires a small built-in amplifier to amplify the voltage fluctuations from a sound source before it’s sent to the mixer?

Dynamic

Condenser

Ribbon

Piezo-electric

Condenser

ORTF is a stereo near coincident technique using two cardioid microphones placed at a(n) ____ degree angle

110

Common mode rejection or Balancing

Splitting a signal into two copies and inverting one copy while being transmitted through a cable in an effort to prevent signal interference

RFI

Interference created by radio signals

EMI

Interference created by electrical signals or fields

Cross Talk

When an audio signal induces current into a cable lying next to it

Which type of cable shielding is used for permanent installations?

Foil

Speaker wire has two conductors but _______ is needed

• Shielding

• No shielding

No shielding

Cross Talk

when a signal from one cable is induced onto the signal of another cable because of their close proximity to each other