Sound Reinforcement

Question 1

Electricity

Answer 1

The flow of electrons

Question 2

Voltage (V)

Answer 2

Measurement of electrical pressure or potential as compared to a zero ground potential.

Can be thought of as: potential energy

Question 3

Voltage

Answer 3

Unit of electromotive force or electrical pressure. One volt is required to send One ampere of current through a resistance of one Ohm.

Question 4

Current and Ampere

Answer 4

Measurement of how many electrons pass through a reference point each seconds. Measured in amperes (A) or (I)

Question 5

Resistance (R)

Answer 5

Property of a conductor that determines the amount of current that will flow as the result of the application of a given electromotive force

Limiting current flows it is referred to as a resistor

Dissipates through heat loss

Question 6

Ohm

Answer 6

Ohm is a unit of electrical resistance

Question 7

Impedance (Z)

Answer 7

Total opposition offered to the flow of an alternating current

Question 8

Earth ground

Answer 8

Ground that uses electrical potential of the earth as a reference

Question 9

Signal ground

Answer 9

Signal potentials (voltages) in a specific piece of equipment such as a microphone

Question 10

Chassis ground

Answer 10

Any conductor that is connected to the devices chassis, ultimately drains to earth ground

Question 11

dB SPL stands for

Answer 11

Decibel Sound Pressure Level
Measure of sound pressure in decibels

Question 12

Microphone level

Answer 12

Lowest level
No signal to -20 dBu

Question 13

Line level

Answer 13

Midrange
-20 dBu to +30 dBu
ie. Mixing console

Question 14

Speaker level

Answer 14

Highest level
Everything above +30 dBu
ie. Power amplifiers

Question 15

Gain

Answer 15

Increase in amplitude of a signal
Expressed in dB

Question 16

Attenuation

Answer 16

A reduction of the amplitude of a signal

Question 17

Shielding

Answer 17

Protecting electronic equipment from electromagnetic or magnetic interference (surround with copper or aluminum and other metals)

Question 18

Cable Gauge

Answer 18

Refers to the diameter of a cable used to carry energy

The higher the gauge # the smaller the diameter the cable will be, and the opposite for lower gauge

Larger cables carry more current and best for long distances

Question 19

AWG stands for?

Answer 19

American Wire Gauge

Question 20

EMI

Answer 20

Electromagnetic Interference
Interference generated from an outside element

Question 21

RFI

Answer 21

Radio Frequency Interference

Question 22

Electrostatic Interference

Answer 22

Unwanted frequencies which can be transmitted between wires

Question 23

Tip-sleeve (TS)

Answer 23

Single conductor shielded cable

Question 24

Tip-ring-sleeve (TRS)

Answer 24

Dual shielded cables and extra conductor on the shaft. Can run left and right mono signals for stereo output

Question 25

IEC

Answer 25

International Electrotechnical Commison
C1-C24
Most common: C13 and C14
Rates up to 250V AC

Question 26

RJ45

Answer 26

Registered Jack
For network and telecommunication connections

Question 27

Neutrik Ethercon vs Neutrik Speakon

Answer 27

Speakon are blue and meant for speakers

Ethercon is essentially an RJ45 for audio/video/lighting (Avioms)

Question 28

OSHA

Answer 28

Occupational Safety and Health Administration

Question 29

DI Box

Answer 29

Direct injection box
Convert unbalanced, high impedance signals to low impedance microphone level signal

Question 30

Condenser microphone

Answer 30

Costly, more sensitive to temperature and humidity, not as good for live sound as dynamic microphones are

Requires phantom power of 48 vdc from the mixing console