Test 4 SPRING 2023

Audio Fundamentals

Balanced Cable

Considered Low impedance or Low Z

Unbalanced cable

Considered high impedance or high Z

What provides common mode rejection (CMR)

Balanced inputs

What does common mode rejection mean

Interference (noise) picked up by the cable will be rejected by the input

What is the PIN side of an XLR connector (male)

The output

What is the socket side of an XLR connector (female)

The input

Male XLR connector (output)

\

Female XLR connector (input)

\

1/4 inch phone plug is considered a

Guitar Jack

What does a tip sleeve TS mean

Mono unbalanced

What does a tip ring sleeve TRS mean

Mono balanced

Stereo unbalanced

Headphone jack

The tip is

\+ (or left)

The ring is

\- (or right)

The sleeve is

Shield (ground)

1/4 in TS - tip sleeve

1/4 inch TRS - tip ring sleeve

What is smaller than the 1/4 “ connector

The Bantam or TT(tiny telephone)

The Bantam / TT(tiny telephone)

What does RCA phone stand for

Radio Corporation of America

What is a unbalanced mono and consumer audio connector

RCA phono

RCA connector

3\.5 mm (1/8”) Mini I I-connectors

Speakon connector

Audio electrical signal is

Analog

Audio signal that is interpreted as ones and zeros

Digital

Computer-based mixer (program)

DAW

Tactile controller for computer-based mixer

DAW with a control surface

Full analog console with added features to control a computer-based mixer

Analog with DAW control

Console inputs and outputs

32x24x2

32 inputs

24 outputs

2 program outputs

What is the icon for an amplifier

What is the icon for trim

What is considered as level control

Trim

Where are trims usually found

Online level inputs and are used to set a course level well the fader sets the fine level

What is the icon for a fader

What are faders

These are variable resistors (potentiometers) or digital encoders

In what systems does the fader adjust the control voltage or control signal which in turn adjusts the audio game

VCA (voltage control amplifiers) and DCA (digital control attenuators)

What processors do larger analog systems include

Dynamic processors

Which is the switches icon

Which is the pan icon

What are panners or panpots

These are panoramic potentiometers (analog)

What are the three different types of solar systems out there

PFL, AFL, and IPL

What are the monosolo systems

Pfl and AFL

What does pfl stand for

Pre fader listen

What does AFL stand for

After fader listen

What does IPL stand for

In place solo or sip (Solo in place)

AUX Master icon

The parts of a meter

What is a device that only attenuates certain bands of frequencies

A filter

What are the three types of basic filters

Low-cut / High Pass

High-cut / low pass

Notch filter

Where is the cutoff frequency

It is 3 DB down from nominal (flat) level

What are considered as tone controls

Shelving equalizers

Bass and treble control is also referred as

Tone control

Image of a shelving EQ

Image of a bell EQ

Which EQ offers the most Equalization control over a signal

A parametric EQ

What type of equalizer is cause phase shift

All analog equalizers

What factors affect the amount of phase shift

The amount of boost or cut, filter slope and slash or Q

What are compressors

Amplifiers whose gain decreases as the input level increases

What are limiters

Compressors whose output level remains constant regardless of the input level

What is a threshold

The input level at which the compressor turns on and gain is reduced

What happens to signals below the threshold

The signals passed through the compressor unchanged this is called unity game

What determines the amount of gain reduction above the threshold

The compression ratio

What is the compression ratio a ratio of

Db in to DB out

What is attack time

The speed with which the processor reacts after the signal goes over the threshold

What is the hold time

The amount of time the gain reduction is maintained

What is the release time

The speed with which the processor stops reacting after the signal Falls below the threshold

What amplifiers game goes down as the input level goes down

And expander

What is the purpose of an expander

To reduce low-level noise (Noise gate)

What is Decay time

The time it takes for the reflected signal to reduce by 60 DB SPL (rt60)

What does a mix of wet and dry signal mean

The closer you are to the source the louder the direct sound and the less you hear the reverberation

What does Decay time Define

Hard surfaces cause the sound to bounce around the room for a longer period of time

What three heads do analog tape machines have

Erase, record and reproduce

What is the creation of flanging represent

The creation of a shifting comb filter using a shifting time delay

What is the creation of pitch shifting

This is varying the playback speed tape provided the ability to raise or lower the pitch of recorded sound

Voltage:

The amount of work required in moving one \n electric charge from one point to the other. Volt is the \n unit.

Current

The amount of charge passing through the \n circuit in unit time. Ampere is the unit.

Resistance

The opposition offered by the flow of \n current in the circuit. Ohms is the units

Power

The product of work done and the number of \n electrons passing through the circuit in unit time. Watt \n is the unit.

the 4 basic units of electricity are

volts, \n amps, ohms, and watts.

Power (watts)

Work Created \n heat, light, amplification, etc.

A doubling of power (watts) yields a

3 dB \n increase

A double of voltage (pressure) yields a

6 dB \n increase.

Inverse Square Law-Doubling the distance

decreases the Sound Pressure Level by 6 dB

Inverse Square Law- Halving the distance

increases the Sound Pressure Level by 6 dB

When a standardized reference power, voltage or \n pressure are used

a specific “kind” of dB is created

The most common types of dB for audio production \n are:

dB-SPL (also A, B, & C weightings) \n • Sound Pressure Level (.00002 Pascals) \n • dBm (1 milliWatt) \n • dBu (0.775 volts) \n • dBFS (0 \= Full Scale (max) in digital) \n • dBV \= (1 volt)

What is sampling like?

This is like “taking shapshots” of the voltage \n level or amplitude at specific intervals

What is the time interval know as

sampling frequency (fs), sampling rate, or Nyquist rate

Nyquist frequency \= ½ of the Nyquist rate \=

the highest audio frequency we can digitize \n accurately (the analog sound that we hear)

Nyquist rate \= sampling frequency

sampling rate (how often we sample or “take a picture” of \n the analog sound)

Violation of Nyquist’s law

(having audio frequencies above ½ the sampling frequency) \n results in the creation of alias waves.

After Sample & Hold

Quantizaing

In digital quality the sampling frequency determines what?

Bandwidth

What does bit depth determine

The dynamic range

How can I find the bit rate?

by multiplying the bit depth by the \n sampling frequency

What is a dither

To prevent quantization error on this a very low \n level noise is sometimes added to the audio (This will increase the dynamic range)

How do you De-Sample

Using a Sample & Hold Circuit

What is an output low pass filter called

anti-imaging filter