Appendix D (Sound Reinforcement) Flashcards
what is electricity
the flow of electrons through wires and circuits
what is voltage
a measurement of electrical pressure or potential as compared to a zero ground potential. potential energy. measured in volts
what are volts
a unit of electromotive force or electrical pressure.
what is one volt equal to
the pressure required to send one ampere of current through a resistance of one ohm
what is current
a measurement of how many electrons pass through a reference point each second.
what is current measured in
ampere
what is an ampere
(A) or (I) is the basic unit of electrical current
what is resistance?
the property of a conductor that determines the amount of current that will flow as a result of a given electromotive force
what is a resistor
a device specifically built for the purpose of limiting current flow
what is an ohm
the unit of electrical resistance
what is impedance
(Z) the total opposition offered to the flow of an alternating current
what is ground
the electrical reference against which voltages are expressed
what are the three types of ground
earth
signal
and chassis
what is earth ground
ground that uses the electrical presence of the earth as a reference
what is signal ground
reference point in which signal potentials (voltages) in a specific piece of equipment such as a microphone are expressed
what is chassis ground
any conductor that is connected to the devices chassis. Chassis ground ultimately drains to earth ground
what is power?
the rate of doing work or rate of expanding energy.
what is the unit of power?
watt
what is a watt?
it represents the amount of work that is performed through heat dissipation
what is a watt equal to?
one joule of energy per second
what is a multi meter?
a device that measures voltage, electronic current, and resistance within a variety of different ranges of values
what does a multi meter look like?
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what is a volt tester?
AKA test lamp, determines the presence of electric voltage
what does a volt tester look like?
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what is a decibel?
DB. a unit used to measure the intensity of a sound or the power level of an electric signal by comparing it to a given level on a logarithmic scale.
What is dB SPL
measure of sound pressure in decibels.
what is 0 dB SPL
threshold for human hearing
what is 130 dB SPL
threshold for pain
what is an audio signal?
an electrical representation of sound in the form of a fluctuating voltage or current
what are standard operating levels?
the amount of power needed to drive the signal coming from a particular source
microphone level?
the lowest level. range from no signal to -20 dBu
line level range?
range is -20dBu to 30+ dBu.
what operates at line level?
the mixing console operates at this level as does most signal processing and electric keyboards
speaker level range?
highest level +30 dBu
what outputs at line level?
power amplifiers
what is gain
gain is the increase in amplitude of a signal
what is gain expressed in
dB
what is attenuation
a reduction of the amplitude of a signal
what is nominal?
the operating level at which an electronic signal processing device is designed to operate
what is the dynamic range
the difference between the maximum electrical signal potential and inherent noise floor
what is noise floor
all unwanted sound in an audio system
examples of noise floor
AC or PA system noise
what is the signal to noise ratio
the difference between nominal level and floor noise
what is headroom
the difference between nominal and maximum output
what do unbalanced cables and circuits use
two conductors: a single active wire, ground/shield wire return.
at what length does it get hard for a cables ground to fend off interference
15 + feet
what is different about balanced cables and circuits
the two signals are sent 180 degrees out of phase to cancel out noise caused by interference. once received the signal is flipped back into phase
what is a conductor?
a material that allows electrical current to flow freely from particle to particle
conductor materials?
copper aluminum tin silver and gold
what are insulators
materials that impede the movement of electrical current
insulator materials
rubber plastic wood
what is shielding
the process of protecting equipment from electromagnetic and electrostatic interference by surrounding it with a conductive or magnetic material.
what material is used for shielding
copper aluminum and other metals
what else is shielding
a means of confining the interference of cables and power lines
what is a cable gauge
the diameter of a cable used to carry energy
what is the standard wire measurement system in the US?
AWG the American wire gauge
the smaller the gauge number
the larger the diameter and opposite
what is EMI
electromagnetic interference generated by an outside element containing radio frequencies
what is emi also known as
RFI radio frequency interference
what is electrostatic interference
unwanted frequencies which can be transmitted between wires
what is a single conductor shielded cable
a cable consisting of a single conductor, commonly used in tip sleeve unbalanced connections
P
what is a discrete dual conductor shielded cable
consists of two independent conductors, commonly used with ring tip sleeve and XLR connections
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what is a speaker cable
individually insulated wire that carries audio signals between speakers and amplifiers. can be a single conductor or multiple conductors housed together
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
What is an ethernet cable
used to send information at high speeds between electronic devices such as computers routers and IP networks. AKA cat 5 or cat 6
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what is a multi channel audio snake
a single cable which houses several discrete dual conductor shielded audio cables. extremely useful for managing several audio channels.
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what are XLR connectors
three pin connectors connect microphones to a mixing board as well as powered speakers
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what are the two common 1/4 and 1/8 inch cables
TS and TRS
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what are neutrik speakon and powercon connectors?
neutrik speakon connectors are an alternative for connecting amplifiers and loudspeakers
Powercon connectors are used as AC power connectors that lock.
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what are IEC connectors
power supply couplers with multiple different applications and configurations
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what are RJ45 connectors
standard for network and telecommunication connections
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what are neutrik ethernet cables
RJ45s connectors designed for video audio and lighting
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
What is OSHA?
occupation safety and health administration
when does OSHA require your employer to monitor your hearing?
after 85 dB over 8 hours
what are direct boxes
DI boxes convert unbalanced high impedance signal into a balanced low impedance mic signal
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what is a dynamic mic
most common and rugged
voice coil that works in conjunction with a small plastic diagram
what is a condenser mic
employs electronically charged backplate that forms a sensitive sound sensitive capacitor
what is microphones polar pattern?
graphical representation of a mics sensitivity in relation to the angle at which sound arrives to the mic
what is an omni directional mic
sensitive at all angles
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what is a cardioid?
cardioid polar pattern AKA unidirectional
sensitive to 0 degrees
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what is super/hyper cardioid
similar to cardioid most sensitive at 0
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what are bi directional mics
the most sensitive at 0 and 180
PICTURE
https://drive.google.com/drive/folders/1eGpB_fW1kMN5uAMnnvkHV-s–iR93mPZ?usp=sharing
what is the proximity effect?
the increase in low end as a unidirectional mic is positioned closer to the source
how to lessen the proximity effect?
roll off around 100HZ
whats a power amp do?
takes line level signal and raise it to a speaker level signal. final component to reach a loudspeaker
PICTURE
what is a peak?
highest momentary power level that a system can withstand
what is program?
a rating based off of a typical rising and falling of power that a system would withstand during a performance
what is continuous?
the amount of power a system can handle going through it continuously
what does a point source loudspeaker do
project sound from a single source
what do full range loud speakers cover
full frequency range
below 100HZ is poor
what frequencies are subwoofers for
below 200 HZ
how many inputs does a big band need?
22 mics
how many monitor mixes are there?
4 mixes
Vocals guitar/keys rhythm and winds
how many input sources for wind ensemble?
21
how many monitor mixes
3 mixes drums rhythm conductor
how many inputs for PMG
21 inputs
PMG monitor mixes
6 mixes
vocals guitar keys bass drums horns
how many inputs for Jazz combo
10 inputs
how many mixes for combo
3
vocals rhythm soloist