exam 1 Review Flashcards
What are the components of a sound wave?
wavelength, frequency, and amplitude
What is a wavelength?
one peak + valley (compression + rarefaction)
What is frequency?
number of wavelengths passing a certain point
True or False: Low frequencies have long wavelengths.
True
True or False: High frequencies have short wavelengths.
True
Define Amplitude.
difference between maximum and minimum pressure
How is amplitude mesaured?
decibels (dB)
What is amplitude also known for in sound?
Loudness
Describe the ear processing sound.
The movement of molecules in the air known as sound enters the external auditory canal. It travels to the beginning of the middle ear, the tympanic member where the ossicles are attached. There are 3 bones in the ossicle the hammer, anvil, and stirrup which vibrate. The stirrup connects the middle to the inner ear where the cochlea is located. The stirrup is attached to the cochlea and the fluid inside of it moves the cilia which then send electrical signals to the brain.
True or False: The cilia pick up lower frequencies first then the higher frequencies deeper in the cochlea.
False. The cilia picks up higher frequencies then lower frequencies.
True or False: The human ear range is 20 - 20,000 kHz.
True
Which Hz range is most sensitive to the human ear?
1000 - 4000 Hz
Define tinnitus
perception of sound when no external noise is present
Define listener fatigue
listeners experience symptoms of physical exhaustion triggered by sound abnormalities
Define equal loudness principle
we do no perceive sound all the same. we put more energy behind lower + higher frequencies
Describe Phase and two types of interferences.
Phase is the time of the relationship between two or more sound waves at a given point in their cycles. Two interferences are constructive and destructive. Constructive is when the wavelengths are in-sync. Destructive is when they are completely out of sync.
Describe a situation how phase problems occur.
sound cancellation, distortion, microphone too close
constructive interference
sound waves IN sync (C - constant)
destructive interference
sound waves OUT of sync (D - different)
Solutions to Phase
3-to-1 rule (1 ft. from source, 3 ft. from mics)
Define polarity
flipping the signal upside, compared to another
What are the types of transducing properties?
dynamic and condensor
Describe the process of a dynamic microphone.
A diaphragm is positioned at the front of the mic responding to the pressure of the sound waves which is also attached to a coil. The coil is around a magnet and vibrates to the changes in pressure resulting in a disturbance in the magnetic field. This induces a small electrical current into the coil of wire, which is the audio output signal.
List characteristics of dynamic microphones.
simple construction, inexpensive, produces low noise, good frequency response rate, flexible environment, rugged, extremely high SPLs
Describe the process of a condenser mic.
It consists of one charged diaphragm and oppositely charged backplate separated by insulated material creating space between the two plates. When responding to sound waves the diaphragm changes the distance between the backplate which alternates the electrical signal voltage build up generating a small electrical signal.
List characteristics of condenser mics.
phantom power, battery, fragile, expensive, excellent transient response, higher OUTPUT level, poor SPLs, quick changes, more accurate to high frequencies
List and describe the four pick-up patterns.
Omnidirectional (all-around), Bi-directional (two directions, front + back), uni-directional (one direction), cardioid heart shaped)
List the family of cardioid mics.
cardioid, super cardioid, hyper-cardioid, ultra-cardioid
Pros + Cons of Omnidirectional Mics.
Picks up sound evenly on all sides, used for ambience; unwanted background noise, picks up more reverb
Pros + Cons of Cardioid mics.
mainly one direction (front of mic), rejects unwanted sound; does not pick up sound well from the back of the mic.
List and describe the four types of stereo recording mics.
- coincident (X-Y) [mics toward each other, cardioids only]
- near coincident (french/ dutch) [mics pointed away from each other, cardioids only, bunny ears]
- mid-side [1 cardioid, 1 bi-directional side pointed]
- spaced [either 2 cardioid OR 2 omnidirectional facing the same source w/ distance between]
What is frequency response?
how accurately do microphones transduce the sound source
what are SPLs?
sound pressure levels
List examples of proximity effects
- unnatural boost in bass frequencies (cardioid mics - only)
- p-popping
- distortion
- phase
describe the frequency response diagram
x-axis (range of frequencies), y-axis (difference level)
* tells us how efficient the microphone is w/ its source
Shure SM 57
dynamic + cardioid
EV RE-11
dynamic + super-cardioid
CAD E100s
condenser + super-cardioid
AKG D880
dynamic + super-cardioid
Shure KSM 32
condenser + cardioid
EV 635A
dynamic + omnidirectional
Define polar response
where the microphone picks up sound the best
What are the two types of consoles?
on-air/broadcast and production
list the characteristics of an On-air console
- sources immediately distributed to the audience
- designed to facilitate rapid transitions from one source to another
- set a specific way
- inputs already set
- stationary
list the characteristics of a production console
- adaptable for various production tasks
- handles many sound sources
- allows sub-mixes
- inputs usually NOT preproduced
- flexible
Where on the console are the inputs displayed?
Faders
What is trim/ gain?
fine-tuning the volume of each input
define cue
previews the input sound source w/o affecting the overall mix
What is VU?
measurement of levels on a console can pass 0 (+3 or +6)
- the average is 0 for best quality sound
What is Peak?
measurement of levels on Adobe Audition.
- the average is -20 for best quality sound
What is an equalizer?
it increases certain frequencies changing the tonal quality
What is pan?
how much sound goes into the left/ right channel
What is the difference between mic input and line input?
mic inputs are pre-amplified to match the line input levels. Line inputs are set to take higher electrical signals.
Each is designed to accept different levels of electricity
How do speakers transduce sound?
electrical -> mechanical -> acoustic energy
What are the common drivers in speakers?
woofer, mid-range, tweeter
What is the process of spiltting in crossover networks?
sending frequencies to the drivers
Describe the crossover networks discussed in class.
passive and active. passive is when the sound is amplified BEFORE the splitting to their drivers. active is when the sound is boosted AFTER the signal has been filtered to its designated driver.
How many types of systems were discussed in class?
2-way: 1.5 - 2 kHz
3-way: 3.5 - 5 kHz
What is the relation to the number of crossover networks a speaker has?
it widens to the speaker’s frequency response
Define linearity
how efficient the speaker system is across the audible spectrum
Describe width with linearity
representing the range of frequencies the speaker processes
What is polarity with speakers?
how the speakers are wired
Describe the sound chain
sound -> mic -> console -> speaker
What is monitor placement and describe two types of placements.
It is the distance between the monitor and the control room operator
- far-field: larger, greater amplification, affected by the character of the room
- near field: ensures sound arriving at the operator’s ear will come directly from the speaker
Define impedance and break down each process.
- electrical: speaker’s opposition to alternating current flow
- mechanical: determined by the cone’s opposition to movement (mass, damping, stiffness)
- acoustic: how efficiently the driver moves the airwaves
module: the frequency response diagram represents
how efficient a mic is at reproducing the audible frequency spectrum
module: a 48v button on a console is designed to
provide phantom power to microphones
module: mic and line inputs on a console are different in that
they are designed to accept different levels of electricity
module: crossover networks are designed to
split the range of frequencies and send them to the appropriate drivers
module: tweeters typically
convert electrical energy into high-frequency acoustic energy
module: identify two things one can check to try troubleshooting an issue of no sound coming through the speakers
- make sure the inputs are turned on
- meters are moving indicating there is sound
- volume control levels
module: identify and describe the three properties of sound
The three properties are amplitude, frequency, and wavelength. Amplitude is the loudness and the difference between maximum and minimum pressure. frequency also known as pitch, regards the number of wavelengths that pass a specific point in time. lastly, wavelength consists of the distance one full cycle of a wave (one peak and valley) is completed.
module: the number of times a wave experiences one compression and one rarefaction during a second is known as…
frequency
module: equal loudness principle shows that the human ear is relatively INSENSITIVE TO…
low bass and high treble frequencies
Cilia are best described as the:
hair-like nerves in the cochlea that move the fluid in the direction of the sound waves
module: if a 100 hz tone and a 1 kHz tone are played at the same level/ volume in a noisy environment…
the 1 kHz tone will sound louder according to the equal loudness principle
module: what occurs when two signals are in phase?
constructive interference
module: what does timbre mean?
Timbre is known as the tonal quality of sound and enables us to distinguish two sounds having the same pitch and loudness.
module: how are the terms octave and frequency related?
the relationship of an octave within a frequency is the 2 to 1 ratio.
module: list the 5 tonal categories and identify the number of octaves each one encompasses
low bass (2), upper bass (2), mid-range (3), upper mid-range (1), treble (2)
module: how does the ear process sound?
The movement of molecules is known as sound which enters the outer ear/ external auditory canal. Sound travels to the tympanic membrane/ eardrum, the beginning of the middle ear, and moves the ossicles (consists of three bones: anvil, hammer, stirrup) attached to it. The stirrp connects the middle to the inner ear beginning the cochlea. The cochlea is filled with fluid moving the cilia (hair-like nerves) and sending signals to the brain with the movement of the fluid.
module: if a guitar amp “goes to 11,” that means it is…
one louder
