CRAS Live Sound Final Exam 3
Questions & Answers 2025/2026
What are the 3 elements of single phase power? - ANSWERShot
neutral
ground
What are the three elements of 3 phase power? - ANSWERSthree hots
one neutral
one ground
What is a ground loop? - ANSWERSWhen voltage moves back and forth between ground via a
signal carrying line
What do ground loops cause? - ANSWERS60 Hz hum
How do you fix a ground loop? - ANSWERSDI box and ground loop switch
What colors are the wires in an xlr cable? - ANSWERSground/shield = green
positive/hot = red
negative/cold = black
What colors are the wires in a US outlet? - ANSWERSneutral = white
hot = black
ground = green
, What do +4dbu and -10dbu represent? - ANSWERScommon line level
how much must the resistance of the mic pre be to function at optimal level? - ANSWERSIt must
be 10x the mic's output impedance
What is +4dBU in dBV? - ANSWERS1.2 dBV
What is -10 dBU in dBV? - ANSWERS0.3 dBV
What kind of splitters lose mic signal when they split? - ANSWERSdigital splitters
When do pre-fader splitters split? - ANSWERSbefore the fader
What happens every time you add a console to an analog split? - ANSWERSThe signal to each
console decreases
What is a VOM and what does it do? - ANSWERSVolt Ohm Meter
It measures AC and DC current
What are the four steps to get any channel to any bus? - ANSWERS1. bring mic pre to 0dB
2. bring channel fader to 0 dB
3. Bus it
4. Bus fader to 0dB
What do power amps do? - ANSWERSBring line level to speaker level
Questions & Answers 2025/2026
What are the 3 elements of single phase power? - ANSWERShot
neutral
ground
What are the three elements of 3 phase power? - ANSWERSthree hots
one neutral
one ground
What is a ground loop? - ANSWERSWhen voltage moves back and forth between ground via a
signal carrying line
What do ground loops cause? - ANSWERS60 Hz hum
How do you fix a ground loop? - ANSWERSDI box and ground loop switch
What colors are the wires in an xlr cable? - ANSWERSground/shield = green
positive/hot = red
negative/cold = black
What colors are the wires in a US outlet? - ANSWERSneutral = white
hot = black
ground = green
, What do +4dbu and -10dbu represent? - ANSWERScommon line level
how much must the resistance of the mic pre be to function at optimal level? - ANSWERSIt must
be 10x the mic's output impedance
What is +4dBU in dBV? - ANSWERS1.2 dBV
What is -10 dBU in dBV? - ANSWERS0.3 dBV
What kind of splitters lose mic signal when they split? - ANSWERSdigital splitters
When do pre-fader splitters split? - ANSWERSbefore the fader
What happens every time you add a console to an analog split? - ANSWERSThe signal to each
console decreases
What is a VOM and what does it do? - ANSWERSVolt Ohm Meter
It measures AC and DC current
What are the four steps to get any channel to any bus? - ANSWERS1. bring mic pre to 0dB
2. bring channel fader to 0 dB
3. Bus it
4. Bus fader to 0dB
What do power amps do? - ANSWERSBring line level to speaker level
