Audio Engineering 101 Flashcards
Noise vs Notes
Music (Notes) is a form of art with sound as a medium,
- Combination of PITCH and DURATION as its foundation.
- sound waves regular and EVENLY SPACED.
Noise is unpleasant to a person because of its irregular wave form, low frequency, and SUDDEN CHANGES IN WAV LENGTH.
-A sound wave repeating component and non-repeating component
Resonance
Natural frequency of an object; ie, bell or tuning fork.
It’s the tendency of a mechanical or electrical system to VIBRATE or OSCILLATE at a certain FREQUENCY when excited by an external source, and to keep oscillating after the source is removed
Analog
Refers to audio recorded using methods that replicate the original sound.
Magnetic audio tape is used to capture speech and music. Vinyl records, vinyl.
Analog technology can wear out or be damaged
Digital Recording
- recording by taking samples of original sound at a specified rate.
- Computers translate the sound into a series of numbers(bits) that APPROXIMATE what we’re hearing.
- Advantage is portability and ability to be reproduced
Properties of digital sound
Bit depth
- The number of bits available for each sample .
- The higher the bit depth, the higher the quality of the audio.
- INDUSTRY STANDARD 16, 24, 32
Sample rate
- The number of samples per second.
- The samples are just points in time. Ie., 44.1 kHz, 48 kHz
- The higher the greater the size of the file
XLR Cable
Have three pins + / - / GROUND
They are used to deliver BALANCED, SHIELDED signal to/from microphone over long distances,
STEREO CABLE
Thought of as a microphone cable.
1/4” Cable
Unbalanced cable.
Mono signal
Susceptible to noise, so the shorter the cable the better is often the suggestion.
Usually used for equipment such as guitars, keyboards, amplifiers, etc.
Patch Panel
- Connects all of the inputs/outputs of outboard gear into a centralized hub.
- Allows to route one device to the next without needing to go behind a rack full of gear in order to change one thing.
- Normalling - How the audio signal is routed through the patchbay
Phantom power
Commonly designated as +48V or P48
- way of sending the DC electrical current required through a balanced XLR cable
So microphones dont need a bulky external power supply such as the ones required for tube microphones.
Widely used as a power source for condenser microphones, which have active electronics.
Direct box
Device that converts signal to unbalanced to balanced.
1/4” to XLR
Dynamic Microphone
- Uses a Transducer, Diaphragm, movable induction coil suspended in a magnetic field.
- Lower frequency response - can take higher output
- Cheap, durable
- For guitar and snare drums
Condenser Microphone
CAPACITOR CONCERT capacitor convert acoustic vibrations into DC electric current thru XLR cable
+48V phantom power to operate
- capture VERY high frequencies
- Vocals
- transducer - large diaphragm and ribbon behind
Work by using a capacitor (or condenser) to convert acoustic vibrations into an electrical current. That means they need a power source like 48V phantom power to operate.
Vocals
Has a large diaphragm and ribbon behind that is a transducer
Difference - side capture VERY hi freq
Ribbon Microphone
- Uses a THIN ALUMINUM of electrically conductive ribbon placed between the poles of a magnet to produce a voltage by electromagnetic induction
- the most natural mics that you can use to capture the sound of an instrument, a voice, and even the ambience of a room.
- figure-of-8 polar pattern, massive low-end pick-up, and natural high-frequency roll-off
- respond to EQ extremely well.
Preamp
- Amplifier takes the low output from a microphone and amplifies the signal to a higher line level
- The GOAL of preamp should be to CAPTURE the sound as clearly as possible
- Built into most audio interfaces
- Budget preamps inherently introduce at least some degree of his
Cardioid
Most common
Easy to get a dry signal as it blends out a bad sounding room, a noisy fan in the background
Ideal for LIVE PERFORMANCE live performance and other situations where NOISE REDUCTION and FEEDBACK SUPPRESSION are needed
Supercardioid
More directive than a cardioid pattern having a bit MORE SIDE SIGNAL and a bit LESS REAR REJECTION
Keeps the signal very dry; you get MAINLY THE DIRECT SIGNAL FROM SOUND SOURCE.
Popular Choice For Close-Miking In Live, Film, And Noisy Environments
Omnidirectional
SAME SENSITIVITY to sound pressure coming from ANY direction.
Recommended in any situation that requires viewers or audience members to hear sounds from MULTIPLE DIRECTIONS
Best in GOOD SOUNDING ROOMS and time-based stereo recordings
Often used for ORCHESTRA recording.
Recordings that were done in a bad sounding room using an omni polar pattern might not lead to a satisfying result.
Figure-8
Same sensitivity at 0° and 180°; it is the least sensitive at 90° and 270°
Recording TWO VOICES at the same time
Recording a SINGING GUITARISTS/instrumentalist
Recording in STEREO
AKG C414 Microphone
It is the microphone of choice for miking up vocals, grand pianos, percussions, and any other sound sources with complex waveforms
Selectable cardioid, hypercardioid, omnidirectional or figure-8 polar patterns
Three switchable pre-attenuation pads at -6dB, -12dB, and -18dB.
Three different bass cut filters
Cloud Microphones (CloudLifter)
increases output volumes for mics when preamps dont deliver enough
Lowers floor noise
They just need a little “push” to sound their best.
Gives mics a 25dB shot of gain, which is more than enough to let them work well with virtually any preamp
Sample
The process of transforming analog musical source into a DIGITAL FILE.
Digital audio recording does this by taking samples of the ANALOG source along the soundwaves at regular intervals
First thing you do when someone sends you mix?
a) Listen to the whole song through
b) Listen to each individual track separately to test the sound quality you have to fal with. What will you have to edit.
What are the 7 when mixing a song?
1) Listen to song and and each track
2) Playing on time and in phase
3) Editing - mistakes, white noise, add fades
4) Mixing - EQ/Compression
5) Vocals - Lead guitar and vocal not playing over another
6) Effects - Reverb./Delay, etc.,
7) Panning
Mixing Order
1) bass/drums
2) acoustics
3) rhythm guitars (if acoustics - do them first)
4) electric guitars
5) piano, strings
6) vocals
B A R E P/S V
What frequency range does kick sit?
- 45-100 hz Punch
- 300-500 hz Boxiness
- 3k - 10k Click
What frequency range does kick sit?
- 50-100 hz Punch
- 300-500 hz Boxiness
- 3k - 10k Click
What frequency range does bass guitar sit?
- 60-100 Hz Weight
- 500-800 Hz Growl
- 2k-3k Snap
- 5k-10k Sheen
What’s frequency range is presence? What instruments?
2k - 5k
Acoustic guitar, organ, piano, voices, cymbal
Whats panned in mono?
Lead vocal, Kick, Bass, Lead guitar (When no vocal)
Where do background vocals sit in the pan?
3:00 & 9:00
What sits in 3:00 and 9:00?
Background vocals, keys/pad, rhythm guitar
Where does lead guitar sit?
10:00 (50% left); Back
Where does acoustic guitar sit?
2:00 (50% right); Middle
Where does the snare sit in the pan?
Just to the right of the kick.
What do we have to make sure of in stereo field/panning?
Mics have to be equal distance when mixing drums.
Why is panning important?
Can make or break the mix.
