TDMM Chapter 13 Flashcards
(96 cards)
1
Q
Amplitude
A
The magnitude of a signal or the intensity of a wave
2
Q
ER
A
Equipment Room
3
Q
Frequency
A
Number of cycles (waves) in a time period
4
Q
Harmonics
A
Higher frequency waves blended with fundamental waveforms
5
Q
LED
A
Light Emitting Diode
6
Q
Phase
A
A waves position in time compared to another wave
7
Q
Wavelength
A
Distance between two points in two wave cycles
8
Q
Name the four basic elements of AV design and integration
A
- The hardware connected together
- Software
- The environment the hardware is in
- Content: Audio, Visual, etc
9
Q
What term is used to describe the action of molecules pressing close together?
A
Compression
10
Q
What is a wavelength?
A
Distance between two points in two wave cycles
11
Q
What term refers to the magnitude of a signal?
A
Amplitude
12
Q
How does the human ear perceive amplitude of a sound?
A
As loudness or volume
13
Q
What is the relationship between the amplitude of a sound wave and loudness?
A
The greater the amplitude of a wave the louder the sound
14
Q
How is loudness measured?
A
In decibels of sound pressure level (dB SPL)
15
Q
What is the dynamic range of hearing for humans?
A
From the threshold of hearing to the threshold of pain
(0 to 120 dB SPL)
16
Q
What term is used to express a waveforms position in time compared to another waveform?
A
Phase
17
Q
How is a phase expressed?
A
In degrees, with 360 degrees representing a complete cycle
18
Q
What does it mean if a wave is said to be 180 degrees out of phase with another signal?
A
That one wave is at its maximum and the other is at its minimum
19
Q
What term describes a problem that occurs when a sound is picked up by two close microphones at slightly different times and summed together on an audio mixer?
A
Comb filtering
20
Q
How is frequency measured
A
Hertz (Hz) or cycles per second
21
Q
What is heard as a pure tone?
A
Simple single sine waves
22
Q
What is the fundamental waveform?
A
A sine wave
23
Q
What type of waveform determines the sound quality?
A
A complex waveform
24
Q
What are harmonics?
A
Higher frequency waves blended with fundamental waveforms
25
What is the visible color spectrum?
A small section of spectrum the eye can see
26
What determines the color of a light wave?
The Frequency
27
What color is at the center of the visible light spectrum?
Green
28
How is the amplitude of a light wave perceived by the human eye?
As brightness
29
How does amplitude affect the brightness of a light wave?
The greater the lights wave amplitude, the larger the waves displacement from the midline and the lights brightness
30
Why do light waves have different tints?
They have different distributions of color
31
What is color temperature?
A measurement of the distribution of colors, radiating from a light source.
expressed in Kelvin
32
What is the basis of the Kelvin scale as applied to properties of light?
The color of light emitted when substance is heated
33
What temperatures are perceived as white?
- 3200K
- 5400K
- 6500K
- 9300K
34
What is the color temperature of candlelight?
1900K
35
What is the range of color temperature for a tungsten lamp?
3200K to 3400K
36
What is the color temperature for daylight at noon with a cloudless sky?
5500K
37
The higher the temperature the ___ the light
Bluer
38
The lower the temperature the ___ the light
redder
39
What type of signals do humans produce and hear naturally?
Analog signals in the form of sound
40
What is the only real restriction to modern audio technology?
The human ear
41
What is the typical range of audio frequencies used by most audio equipment?
10 Hz to 30 Khz
42
True or False
Modern AV systems no longer involve the use of analog signals
False
Analog components include microphones, speakers, mixers and analog signal amps
43
Name three audio level categories
- Microphone
- Line
- Speaker
44
Name the two typical types of line levels
- Professional ( +4 dBu)
- Consumer ( -10 dB referenced to 1 v (dBv))
45
What are the three connection points for a balanced audio circuit?
- Conductor carrying the signal just as it originated (+)
- Conductor carrying the signal with opposite polarity (-)
- Electrical ground (usually the shield)
46
What makes a balanced circuit?
When two signal conductors have the same impedance relative to ground
47
What is the benefit of using balanced circuits?
They provide for a higher quality signal with less noise over long distance runs
48
Name two disadvantages with balanced circuits
- Expensive to manufacture
- Time consuming to terminate
49
Why do microphone levels need to be balanced?
Their extremely low level requires the best possible connection
50
What is the sampling rate?
The number of times a sample is taken per second
51
What does the Nyquist frequency represent?
The highest frequency of the analog signal being recorded. It is equal to half of the sampling rate
52
What is bit depth?
The number of bits that describe a signal
53
What is the resolution of a digital audio signal?
The range of numbers that can be assigned to each sample
54
What is quantization noise?
The error between the actual analog signal and the digitized value
55
What bit resolution is commonly used with internet voice devices?
8 bit
56
What bit resolution is commonly used with audio digital versatile discs?
24 bit
57
Name the three primary standards for analog video
- NTSC
- PAL
- SECAM
58
What term describes the process of coordinating the signal information with respect to time?
Synchronization (sync)
59
Name three elements needed to create a complete video image
- Horizontal sync
- Vertical sync
- RGB
60
What term refers to the range of frequencies that can pass through a medium?
Bandwidth
61
What is the bandwidth of human vision?
430 to 750 trillion Hz
62
How is bandwidth assessed in electronics?
In terms if frequency of voltage rather than light
63
What will happen when electric frequencies fall out of a circuits bandwidth?
The frequencies will no longer be detected
64
How does composite sync affect signal stability?
Composite sync reduces signal stability
65
True or False
All full bandwidth signals are too robust to be readily handled by most processing equipment
True
66
What is the method of creating bandwidth limited signals that combines the sync information with the signals for brightness?
Luminance or Luma (Y)
67
Human perception of light is most sensitive to what spectrum of light?
yellow/green
68
Human perception of light is least sensitive to what spectrum of light?
Blue
69
How does the color encoder or matrix create the Y?
It strips the brightness information from the RGB signals and adds it up the make the Y
70
Why is component video used extensively in the production environment?
Because of its quality and lack of artifacts
71
What is an RF video?
A composite video with two audio channels
72
Name five common digital video interfaces
- Digital Video Interface (DVI)
- High Definition Multimedia Interface (HDMI)
- DisplayPort
- Serial Digital Interface (SDI)
- HDBaseT
73
Name the three primary digital television (DTV) Standards
- Integrated services digital broadcasting
- Digital video broadcasting
- Advance television systems committee standard
74
Where is the integrated services digital broadcasting standard used?
Japan
75
Where is the digital video broadcasting standard used?
Europe, Australia and Asia
76
Where is the ATSC standard used?
North America
77
What is the aspect ratio for SDTV programs?
4:3
78
What is the aspect ratio for HDTV programs?
16:9
79
What is serial communication?
A form of data communications where information is sent sequentially, one piece at a time, down a cable
80
What is the limit for cable length per RS-232 specifications?
50 ft maximum
81
What would happen if the settings for an RS-232 device were incorrect?
The device would no longer be controllable
82
Why are RS-422 cable runs able to be longer than RS-232 runs?
Because RS-422 is balanced
83
What is the advantage if using RS-485 serial communications over RS-422?
The RS-485 signal supports multiple devices on the same line
84
What is the communications protocol used for computer networking technologies over the internet?
Transmission Control Protocol/Internet Protocol
(TCP/IP)
85
Are IR controls one way or two way devices?
One way
86
How do contact closures communicate?
through changes in current or voltage
87
Why are dark wall colors used in projection rooms and movie theaters?
To absorb unwanted ambient light
88
What is recommended aspect ratio to use when sizing presentation spaces?
2:1
89
What is the optimum viewing angle?
45 degrees horizontally to each side of the center axis of the display
90
What dictates the seating layout for a communications space?
AV sightlines
91
What is the average seated head height?
4 ft
92
What is the average seated eye height?
3.5 ft
93
How are sightlines arranged in a single row vision seating layout?
The vertical sightline of the viewer passed over the heads of the persons in the row ahead
94
How are sightlines arranged in a double row vision seating layout?
Between the heads of the person in the first row ahead and over the heads of the person in the second row ahead
95
What is millwork?
Custom fit cabinetry
96
True or False
All electronic equipment produces heat?
True
