MidTerm Review

What are the four elements of sound

Frequency (Tone or Pitch

Duration (Length)

Amplitude (Intensity) [Measured in dB SPL]

Waveform What differes same pitch (Fundamental) Between Instruments [Harmonic content] (Overtones)

Sound definition

Is a vibration of air molecules that proagates as an audible wave of pressure through a transmission medium such as air water or other materials

Hertz is defined as?

1 full cycle + / - per second

Human hearing range

Humans can hear sound waves with frequencies between about 20HZ and 20KH

4 basic sound waves

Sine

square

triangle

Sawtooth

frequency band descriptions

Sub bass

bass

midrange

highmids

presence

high

brilliance

Sub-Bass

The very low bass between 20HZ and 60HZ more felt than heard Gives low sounds power

Bass

The bass between 60HZ and 250HZ responsible for the moomy sound

Mid-Range

The midrange between 250HZ and 2Hz sometimes called the lower mid range can cause listening fatigue if overdone

High Mids

The upper midrange between 2khz and 6 khz can affect the important speech recognition sounds

Presence

The presence range between 4khz and 6 Khz responsible for clarity and recognition

High Frequency

Between 6khz and 16khz

Brilliance

Too much emphasis between 6khz and 16Khz can cause sibilance on vocals

Digital audio

Mathematical representation of analog sound

2 Fundamentals of digital sound

Sample rate

Bitrate/Depth

Sample rate

Sampling the process of taking discrete measurements of an electrical signal at various moments in time. The sample rate is the frequency of when these measurements are taken

Bitrate/Depth

The number of bits used per sample the more binary digits included per sample the grater the accuracy of the measurements. 6dB of dynamic range per bit

Digital audio file

WAV/AIF Uncompressed

MP3/AAC compressed

Pro tools Important keystrokes

Play [Spacebar]

Stop [Spacebar]

Return to zero [ReturnKey]

Mix/edit window Toggle [Command/=]

Save [Command/S]

(PT) Selecting tracks

Shift and click to add selection

command and click to single select/deselect

(PT) Edit modes

Slip- In slip mode clips can be moved freely within a track or to other tracks in this mode it is possible to place a clip so that there is space between it and other clips in a track when the track is played back this space is silent it is also possible to move a clip so that it overlaps of completly covers another clip

(PT) Editmodes 2

shuffle in hsuffle mode you can move tirm delete cut or past clips freely within a tack or to other tracks but their movement is constrained by other clips in a track they automatically snap to each other you cant hen shuffle their order but you cannot seperate them from each other and you cannot make them overlap as in sli

(PT) Corssfading

The process of fading ebtween tow clips of audio to prevent pops clicks or sudden changes in sound

[The shortcut is Command/R]

Types of tracks

Audio track

Aux Input

Madterfader

Audiotrack

Allow you to import record and edit audio in a wavefrom display audio tracks can be mono stero or any supported multi channel format

Aux input

Auxilary input tracks provide the same signal routing options as audio tracks ecept that their input must come from an internal bus or hardware input

Master Fader

A Master Fader is a single fader that represents the sum of the output used to control hardware output levels and bus paths master fader tracks control the overall level fo the audio routed to the session main output paths or busses

Microphones

Dynamic

Condenser

Polar patterns

Dynamic Mic

Are passive which means they do not require a power source

theyre rugged robust and reliable

Since dynamic microphones have a weaker signal than condenser mics they must be placed relatively close to the audio source

Condenser

Condenser microphones require a power source which can come from a phantom power supply or a battery

Condenser microphones and have better high frequency response characteristics

They have higher fidelity than dynamic microphones but th they are less durable. typically more expensive too

Polar Patterns

Omni

Unidirectional

Cardioid

Super Cardioid Tighter pickup patterns in front (Relative to a cardio) but slightly more sensitive to the rear.

Hyper cardioid Extermely tight pickup pattern in front but not as much rear rejection as a super cardioid

Figure-8 The same pickup pattern in the front and the rear

Amplifier

A device that tracks the amplitude of an incoming signal and proportionally increases the voltage, current or power of the signal by adding power from another source

Attenuation

The process of decreasing the amplitude of a signal as it passes from one point to another along attenuation circuits typically uses resistors to reduce the voltage of a signal in audio The effect of such attenuators is usually expressed in decibels.

Balanced audio

An audio line comporiing three conductors two carrying singal and a ground wire where one of the singla wires carries the sound and the other carries an inverted copy when the singal reaches the destination the inverted copy is fipped and added to the orginal any noise that has been induced into the singal is also inverted when this is combined with the univerted noise it cancls it out balanced lines thus are less sucepible to hum and can carry audio singals over longer distance blanced audio lines typically use 3 pin XLR or ¼ inch tip ring sleeves TRS phone connectors

Cardioid

A microphone with a directional pickup pattern that is most sensitive to sounds coming from the front and sides which rejecting sounds coming from the rear the pickup pattern is roughly heart shaped hence the name cardrioid

feedback

A condition where the output of a circuit recycles through its input acoustic feedback is a whine or howl that occurs in live audio situation where an amplifed sound re enters a sound system through the same microphone that reproduced the original sound

Highpass filter

A circuit designed to attenuate or cut frequencies that fall below some designated point while allowing higher frequencies to pass unaffected

Microphone pre-Amplifer

A device that prepares a microphone signal to be processed by other quipment micrphone singals are often too weak to be tramitted to units such as mixing concloes and recording devices with adequate quality

Proximity Effect

A boost in the low frequency response of a directional microphone The phenomenon begins when the source is about two feet away from the mic cap

Roll off Filter

A circuit that attenuates a signal that is above (Lowpass filter) or below (Highpass Filter) a specified frequency for example microphones frequently have a bass roll of filter to remove wind noise and or excessive breath pops

transducer

A device that transforms energy from one from to another examples of electromanatical transuces include microphones and loudspeakers

Equalization

An equalizer allows the sound in specied frequency bands to be amplifed or reduced to adjust the quality and character of the sound

Notch/Bell

adjusts frequencies over a dertermined range. the range can be wide or very narrow

Shelf- Very basic

Low shelf- passes all frequencies but attenuates or boots frequencies below the shelf frequency band by a specified amount

High shelf passes all frequencies but attenuates or boosts frequencies above the shelf frequency band by a specified amount

Pass filters

Low pass Removes frequencies above the sleected cutoof and passes everything below

Highpass filter Removes frequencies below the sleected cutoff and passes eveything above

Graphics

Gives you the ablity to adjust a range of frequencies using a bank of slider controls that are venly spaved to boost or attenuate the singla through the aduio spectrum

Parametric equalizer

most common and flexible multiband equalizer has fully configurable and adjustable frequency band that can be individually enabled or disabled to cut boost and filter indivdiual frequency rnages wit h the highest precision

Gain

sets the level of the selected band this parameter is often deactivated when the lwo pass or high pass filter shape is selected

Q (width or resonance)

contorls the badnwidth by allowing you to widen or narrow the selected frequency band

Graphic Vs semi parametric vs parametric EQ

Graphic

Parametric

Semiparametric

Graphic

Used to shape the overall sound and to tune a room or space

Parametric

Used for precision to surgically shape indivdual sounds

Semi Parametric

Less options than a parametric Eq used to shape a tone and not very flexible

Input Gain

The level of the audio going into the compressor

Threshold

The level that the audio will start to attenuate once reaching threshold

ratio

how much the level is attenuated once reahcing threshold

Attack

How quickly the compressor attenuates once reaching threshold measured in milliseconds

release

The rate attenuation stops once below threshold measured in milliseconds

Output/Makeup Gain

Raise the level out of the comrpressor to match the rest of the audio