Intro to recording Flashcards
error protectiong and interleaving
does some math so you can detect a error later then mixes it up
Gain reduction
how much db is lost after compression
dither
high fq added to make sure the analong signal covers at least 2 quantization levels
Threshold of pain
10,000,000,000,000
error deduction and correction
uncrambles the data on disk
How did you use tape delay
the time it takes the tape to go from the record head to the playback head creates delay
low cut
removes low fq
Pure tone/sine wave
A sound that consist of a single basic frequency
what is the Robinson and Dadson curves
Equal loudness contours
why put a speaker in an enclosure
It capture the rear rendering energy
What is the anti alias filter?
An high cut smoothing filter
Octaves
Double of frequency
wavelength
speed of sound DIVIDED BY frequency
Pressure gradient
Whats an alias fq
getting a fq in the out put that was never at the input
Limiter
sets a ceiling, 20:1
Digital audio
Computer based encoding and decoding of a waveform
Pitch
Lowest to highest (relations of frequency)
high cut
removes high fq
Amount of availible numbers for a 16 bit CD
65536
the 4 ways to make reverb
- Chamber (in a room)
- Spring
- Plate
- Digital
20 Hz to 20k
What a human ear can hear
Heads
send in a voltage you change the magnetic field
Cardioid
Flutter
fast variations in tape speeds
Tape speeds (15-30 ips)
pushing the fq high enough to push gap loss
sample
instantaneous snapshot of amplitude
Q
when you choose a ratio, q will make the adjustment to fit it. no matter where the center fq is
Dynamic microphones
Creates a voltage by the moving of a conductor in a magnetic feild
What will happen if a barrier is larger then half of the wavelength?
It will reflect it
sample and hold
sampling a point on a signal, then waiting a little before sampling another point.
Reverbs
reflections so close that it makes a wash of sound
Proximity effect
Pressure gradient design
More low fq output the closer it is to the sound source
Passive radiator
Max the use of the rear radiating energy (pressure inside the speakerbox)
quantization error
theres an finite amount of analog signals and a certian amount of available numbers, so they estimate
Ports/vents
A opening that utilize the rear radiating energy
RT60 reverb time
how long it take to decay 60db
Pressure design
Cross talk
Adjacent tracks on the tape magnetize against each other
Bi-directional
Pick up in the front at back
2 direction
Reverse Polarity
Tuning the positive negative and the negative positive
Why do we use decibel
The range of human hearing is enormous
the human perception of loudness is exponential
Digital Audio advantages
- Using Comupters to edit music
- farther dynamic range
- can take alot of damage and still can get your data back
- faint cross talk and print through
- no wow and flutter
Expander
an varible amplifier where any signal below an set threshold would get quieter
Complex tones
Made of more then one frequency
Tape
what is made of (storing a magnetic field that changes in a way that an analgist to the wave the air pressure change)
A bunch of finely crushed magnet on plastic /the formulation of the crushed magnets can vary
what is the result of the balance of the harmonics
Timbre
Condenser/capacitor
o Something that can store a charge
o steady voltage goes in and varying voltage goes out by the way the diaphragm is move
phantom power goes to the external pre amp and store a charge
Point source
Omni directional theoretical sound source
Head order
Erase
Record
Playback/reproduce
Tape hiss
White noise
whats is quantization
the process of assigning analog signals to the nearing avalible number, the quantization levels
Hard knee
instantly gets compressed after passing the threshold
Attack time
how long a compression begins once a signal past the threshold
disavantage
- Musicians play worse
- lower level signals gets distorted
decibel
10Log Pm/Pr (powered measured/ reference power)
Transducers
Changes a kind of energy to another kind of energy
Twice as loud is
10 times the power
Effect of room surfaces
(doubling of energy) 3db more in your direction by each barriers
2 walls and a floor will get you 9db and it will sound twice as loud
a lot of low fq. When a speaker is put in a corner
4 parts of reverb
- Inital sound
- Early reflections
- onset of reverb
- decay
Tape saturation (tape compression)
All the magnetic are used up and the tape is saturation and distorts
Sounds cool on a lot of things (especially from rock music)
Pumping and breathing
audible hearing compressing going in and out
Why do we use dynamic processers
- To make something sit better in a mix
- Protecton
- Reduce dynamic range
- effect or manipulate dynamic range
- dynamic range in music would be larger then the dynamic range of the storag media
digital to analog convertor
takes a voltage and turn it into a corresponding number
Timbre
The characteristic sound of anything
Parametric EQ
continuous control on the center, boost/cut, and Q
Analog
The wave form that we store is analogist to the wave from in the air
Reverse order of digital Audio
- Error detection and correction
- demultiplexer
- digital to analog converter
- sample and hold
- anti alias filter
- dither generator
Bias
Very high fq (15000 hz) that we add into all analog recording to fixed zero cross distortion
On axis
Where you get the best sound
Unity gain
not boosting or cutting the signal
Pink noise
Equal energy per OCTIVE
What important colcusion might an enginner draw from the Robinson and Dadson Curves
- You should always mix low
- perception varies on how loud the music is
equlization
fq dependent control of amplitude
Twice the power is
3db
What do a microphone polar pattern show
where sound is picked up at and where it rejects
Omni
Equal sensitive in all directions
Pressure design (draw it)
Sound can only get to one side of the diagram
Band width
The range of fq the will be effectied from being around the center fq
Multiplexor
Turn 16 bit parallel info into 16 bit cereal info
Print through
When one winding of tape magnetize its adjacent winding of tape
Compressors
A varible gain amplifer where, above the set threshold, output would gain less as input increases
Graphic equalizer
Graphically shows you what you’re doing to the fq responce
analog to digital convertor
take a number and turn it into a corresponding voltage
Dynamic range
The quiet sound something can produce to the loudest sound with a little distortion
Frequency
Cycles per second
White Noise
Equal energy per FREQUENCY
Order for Digital Audio
- Dither generater
- Anti alias filter
- Sample and hold
- Analog to digital converter
- Multiplexor
- Error protection and interleaving
Wow
slow variations in tape speeds
Gap loss
When a fq is high enough (making the wave form shorter) it can fit in the gap and playback see no different and play
shelving filters
boost/cut all fq at the same time
What do you need for sound? 2 Things
Motion and medium
soft knee
eased into compression after passing the threshold
side chain
one sound controlling another sound
Release time
The time it take a signal to go to unity gain after dropping under the treshold
What is the symbol of Reverse polarity
A circle with a line through it
Zero cross distortion
Anything near zero become zero
Fixed by sending a very high fq tone
Threshold of hearing
the quietest sound a healthy person could hear
Delay
Refections you can hear individually
wavelength size
About 1100 feet per second
2 to 1 rules
nyqust found it
when your sample fq is twice the highes fq you record, nothing will happen
breaking this rule will result in making alias fq
