Exam Revision Flashcards
Which instrument would produce the longest soundwave out of bass guitar and flute?
Bass guitar
What frequency is one octave higher than 440Hz?
880Hz
Which digital audio resolution has the wider dynamic range: 16 bit or 24 bit?
24 bit
What is the maximum dynamic range of a 12 bit digital audio resolution?
72 bit
What is the maximum dynamic range of a 20 bit dynamic audio resolution?
120 bit
What does the term ‘Kbps’ mean?
Kilobytes per second
How many samples per second are required for CD quality audio?
44.1kHz
Which digital audio format uses compression?
MP3
Explain the DAW process of ‘time compression’
Decreasing the length or speeding up the audio without affecting the pitch
Why is audio sometimes ‘choppy’?
Transfer speed or access speed of the USB is insufficient
The SPL is measured at 10 metres from a constant sound source and is found to be 60dB. What would the SPL be at 20 metres from the same sound source?
54dB
What is the function of the insert?
To allow access to the signal path before the EQ section
What is the function of the input sens (gain)?
To adjust the amplitude of the main mix
What is the function of the aux pre?
To hear the sound before it reaches the main mix
What is the function of aux post?
To hear the sound after it is sent to the main mix
What is the function of assign 1-2?
To send the channel output to buses 1 and 2
What is the function of a HPF?
Allows high frequencies to pass through
Removes unwanted bass frequencies
Removes plosives
Gives a clearer vocal sound
What is the function of LF Freq?
To select the frequency below which signal can be boost or cut
What kind of cable can carry phantom power?
A balanced cable
What does the term S/PDIF stand for?
Sony Phillips Digital Interface
How many channels of audio does a standard S/PDIF cable carry?
2
What voltage does a standard GPO (general power outlet) provide?
220-240V
What is the maximum current that can be drawn from a standard GPO?
10A
What is the maximum power that a standard GPO can provide?
2400 watts
Describe a method for tuning or equalising a PA system
Feed pink noise through the PA. Use a microphone and spectrum analyser while adjusting the front of house graphic to achieve a flat response
What does the term RT60 mean?
The time taken for a sound to fall 60dB below its original intensity
What does SPL stand for?
Sound pressure level
If you double the distance, how much does the SPL drop?
6dB
What is the implication of using a 5A fuse instead of a 2A fuse?
The fuse will let more electricity into the system and could potentially blow the speakers or the electronics inside the amplifier
Name two kinds of EQ
Selectable frequency EQ
Parametric EQ
Name two kinds of other EQ
Graphic EQ
Notch filter
Band pass filter
What are the characteristics of a notch filter?
A notch filter is very specific and is often used on set in TV and film to get rid of select frequencies
Define Parametric EQ
Multi band variable EQ which adjusts the amplitude, frequency and bandwidth (or Q)
Define Graphic EQ
Allows levels to be boost or cut at a series of evenly spaced out frequencies
What is Graphic EQ used for?
To tune the room, to help control phase cancellation and to get rid of resonant frequencies in the control room
Define the ratio of compression
How hard or how much you compress a sound
What does ADSR stand for?
Attack, decay, sustain, release
Define the term ‘threshold’
The level at which an effect begins to work
What is the frequency range of the human ear?
20Hz - 20kHz
What is the fundamental range on a four string bass?
41Hz - 260Hz
Describe the following editing function: Normalise
The loudest peak in volume is detected, and the volume of the entire file is increased to maximum without clipping the peak
Describe the following editing function: cross fade
To fade out one sound whilst fading another in
Describe the difference between gain and volume
Gain is the amount of signal being passed through whereas volume is how loud a sound is in regards to a person’s perception of hearing
List two devices you would connect to auxiliaries
Foldback
Graphic EQ
What is the difference between a graphic and parametric equaliser?
Graphic EQ can be adjusted at fixed frequencies whereas parametric EQ can be adjusted at variable frequencies/width
What is phantom power and when is it required?
48V dC power which is required for condenser microphones and DI boxes, and is supplied at the microphone preamp or from an external power source
Where would you connect an external compressor unit to a mixing console?
At the insert point
How does an enabled PRE fade switch on a mixing console affect an auxiliary unit?
The signal is sent to the unit independent of the fader
Describe the difference between a balanced and an unbalanced connector
Balanced signals can cancel out inducted interference. The difference is the number of connections - unbalanced connectors have in phase and earth. Balanced connectors have in phase/out of phase earth.
What is the function of a crossover?
It divides an audio signal into separate frequency ranges, for example, low, mid, high
Describe the difference between an active and a passive speaker sound system
An active system is powered within the unit. Passive systems need an additional power amp.
Describe the following term: watts
A measurement of power output
Describe the following term: ohms
A measurement of resistance
If two signals mixing the same source are out of phase, what is the effect on the sound and how is this caused?
The result is phase cancellation, which is caused by identical wavelengths. Modulation could occur.
0 decibels SPL is commonly known as the threshold of:
Hearing
120-130 decibels SPL is commonly known as the threshold of:
Pain
What is the musical interval between the frequencies 300Hz and 600Hz?
One octave
What is the function of Pin 1 on a typical XLR connector?
It is the Earth pin
Explain why it is not advisable to use instrument cables to connect power amplifiers and speakers together
Because the cables have the wrong impedance
Two types of broadband noise are commonly used as calibration tools in audio production and sound reinforcement. They are named after colours. What are they known as?
White and pink noise
Provide two different uses for TRS connectors in audio production
To connect an insert or a stereo signal
List three tasks you would perform when normalising a mixing console
Turn down auxiliaries, turn down faders and turn off phantom power