Audio, Video, and Streaming Media Technologies
Streaming media requires a minimum bandwidth for uninterrupted streaming. What is the minimum network speed recommended for streaming 4K video?
25 Mbps
When planning for the placement of a projector and screen, the viewing angles for all viewers should be between ? and ? .
25° / 50°
When the power is doubled, the sound will increase by ? .
3 dB
Bluetooth is a wireless standard for exchanging data over distances of up to ? .
30'
The layout of speakers for surround sound require the use of a minimum of ? speakers.
5
What is the maximum viewing distance from the display?
5 times the width of the display
Every time distance doubles, the volume decreases by ? .
6 dB
Speakers should be separated by ? .
8' to 12'
Adding a ".1" to the end of "5.1" system indicates the addition of ? .
A subwoofer
Wireless speakers do not need wires for audio transmission, but they do require ? .
AC power or DC power
A distributed audio system will always include which of the following?
Amplification and speakers Audio source(s) and control devices Distribution equipment
? are the final documentation of work performed, showing the accurate end result of a new installation or retrofit.
As-builts
? is the relationship between the width and the height of an image.
Aspect ratio
? refers to the overall lightness or darkness of the image.
Brightness
Which speaker in a surround system reinforces dialog and vocal imaging?
Center
? video is typically an analog video signal transmitted over three conductors to carry five different frequency bands.
Component
? is the difference in brightness between objects or areas in the image.
Contrast
What is the difference between the darkest and brightest part of a displayed image called?
Contrast ratio
In A/V cabling, if there are hums, buzz, pops, or crackles in the audio and distorted video, it is likely interference from ? .
EMI/RFI
? is the observable area a person can see with their head in a stationary position.
Field of view
Which of the speakers in a surround sound system reinforces dialog?
Front center
Which of the speakers in a surround sound system provide the main audio stage?
Front left and right
Which of the following is not one of the five home theater elements?
Furniture
There are several choices for transmitting digital signals, but the de facto standard is ? , a digital replacement for analog video standards.
HDMI
Frequency of sound is measured by the number of cycles per second. This measurement is called ?
Hertz
What would be the first and most important step in designing a distributed audio system?
Interviewing the client
? is a measurement of visible light from a source.
Lumens
In a multi-source-multi-zone audio system, an audio source can be independently selected, allowing different music to be listened to in each zone. Source selection works through a ? .
Matrix
What is the purpose of a magnet in a speaker?
Provides permanent magnetism used to interact with the voice coil as electrical energy flows through it
The ? of an image is the number of pixels in the image.
Resolution
When there is contact between two or more conductors, it is called a(n) ? .
Short circuit
The ? wireless technique deliberately spreads the signal across the frequency domain, resulting in a signal with a wider bandwidth.
Spread-spectrum
? is the most commonly watched form of video content today.
Streaming video
Why does a constant voltage system run an audio signal at a higher voltage and lower current?
To minimize power loss over long cables
A sight line is the unobstructed line of vision between a viewer and the displayed image.
True
A zone refers to a listening area and is not defined as being a room; it can be made up of multiple rooms. A good rule of thumb is when rooms are not separated by walls, they should be the same zone.
True
HDMI is a proprietary audio/video interface for transmitting uncompressed video data and compressed or uncompressed digital audio data.
True
It is best practice to coordinate with the builder to reinforce and brace the structure where a display, projector, or screen will be mounted.
True
One should always follow the manufacturer's documentation for the appropriate method of wiring speakers and control devices based on their components.
True
The six proven steps of troubleshooting—preparation, examination, analysis, solution, testing, and documentation—should be followed at all times.
True
The technology behind video compression is known as a codec, an abbreviation of compression/decompression.
True
When electrical energy is applied to the voice coil, the magnetic field opposes the fixed magnet. This reaction causes the diaphragm to move back and forth, creating soundwaves.
True
What is the purpose of a driver in a speaker?
Vibrates the diaphragm to create sound waves
The loss of signal strength is known as ? .
attentuation
A(n) ? is needed to stream media.
broadband connection
A(n) ? occurs when one conductor in a pair is connected to the wrong pin at both ends of the cable.
cross pin
When connection types are limited on a piece of equipment, it is always better to choose a(n) ? connection over a(n) ? connection.
digital / analog
To increase volume by three decibels, ? the power/wattage. To decrease the volume by three decibels ? the power/wattage.
double / halve
To save time, use the same holes drilled by other trades to run the cables.
false
A(n) ? happens when equipment grounds are connected at more than one point, causing unwanted current that was not part of the original signal to flow through the circuit, likely on the cable shield.
ground loop
A ? is a physical space with speakers, and may have a separate volume control.
listening area
The symptom of a ground loop in audio is a ? coming from the speakers.
low-frequency hum
A(n) ? , also known as a video router, is an electronic component designed to route multiple input sources to one or more display devices.
matrix switcher
The ? pixels in a given measurement, the ? the resolution.
more/higher
One of the easiest ways to improve the sound in a home theater is to ? .
move seating away from the walls
A ? is a handheld device that performs analog or digital measurements including voltage, current, resistance, and the changes in each measurement.
multimeter
When there is no continuity on a conductor or pair, the installer needs to fix a(n) ? .
open circuit
Thomas Edison invented the first audio source, the ? , in 1877.
phonograph
Sound performance is impacted by ? in the wire carrying the signal to a speaker.
resistance
When there is no sound from any source in an audio system, there is usually a problem with the ? .
source distribution amplifier
When a cable cannot be found, a "Fox and Hound" test is performed using a ? .
tone generator and probe
Avoid using lighting fixtures or loads that use a(n) ? because they can produce unwanted noise.
transformer
Video problems typically relate to one of four categories: display adjustments, video distribution system performance, sources, and media or transmitted video signals
true
A cable tester used to check for continuity on twisted pair cable or coaxial cable with compatible connectors is known as a ? tester.
verification
Frame rate refers to the number of frames displayed by the source media in ? .
1 second
Optimal viewing distance from the screen when watching a 1080p or HDTV display should be ? times the image size.
1.5 to 2.5
Electrical power or lighting wiring should not run through the same pathway as A/V cabling. Keep a minimum of ? separation and cross at a 90° angle.
12"
What is the minimum viewing distance from the display?
2 times the width of the screen
What is the audible range of frequencies that humans hear?
20 Hz to 20 kHz
Which audio source is an analog source?
-Magnetic tape player -Radio -Turntable
Drag-and-drop these troubleshooting steps into the correct order.
-Preparation -Examination -Analysis of the problem -Solution -Testing -Documentation
The installation process of a distributed video system happens in four phases. Place the following steps in order from the beginning.
-Site walk through -Pre-wire -Trim-out -Final installation
The components of a distributed video system include ?
-amplification and processing devices -control devices -distribution components -sources -viewing equipment
An A/V receiver may be able to perform which of the following?
-audio signal amplification -decoding of surround formats -deinterlacing of composite or S-video inputs and conversion into progressive scan -network access
Digital audio is the preferred method for transporting audio signals because it ? .
-can be copied and amplified, retaining quality -can incorporate multiple audio signals into a single stream -does not degrade with distance -is less susceptible to interference -reduces the cost of signal transmission
If the display image is too large, ? may occur.
-eye strain -headaches
