CTS-D Calculations Flashcards
An architectural drawing was created using the U.S. customary scale of 1/8 inch = 1 foot. You measure a distance of 4.25 inches on the drawing. What is the actual distance
The actual distance is 34 feet
An architectural drawing was created using the SI scale of 1:50. You measure a distance of 52 mm on the drawing.
What is the actual distance in millimeters?
The actual distance is 2,600 mm
An architectural drawing was created using the SI scale of 1:200.
You measure a distance of 13 mm on the drawing. What is the actual distance in millimeters?
The actual distance is 2,600 mm
An architectural drawing was created using the U.S. customary scale of 1/4 inch = 1 foot. You measure a distance of 5 and 3/8 inches on the drawing. What is the actual distance in feet?
The actual distance is 21.5 feet
A screen has an aspect ratio of 1.78:1 and the following height dimension: 165.3 inches (4199 mm). Determine the width and diagonal of the screen.
Rounded to the nearest tenth of an inch, the screen width is 294.2 inches.
Rounded to the nearest tenth of an inch, the screen’s diagonal is 337.5 inches.
An existing screen is 216.5 inches (5499 mm) wide by 216.5 inches (5499 mm) high. A projected image with a 1.78:1 aspect ratio covers the entire width of the screen. What is the image’s height?
Rounded to the nearest tenth of an inch, the screen height is 121.6 inches.
What is the aspect ratio of a screen with a width of 108 inches (2743) mm) and a diagonal of 135 inches (3429)?
Rounded to the nearest hundredth, the aspect ratio is 1.33:1, or 4:3
You require a 16:9 screen with a height of 60 inches (1524 mm).
What will the screen’s diagonal be?
The screen diagonal is 122.4 inches.
A 16:9 screen will be installed in a lecture hall. The screen’s diagonal is 72 inches (1829 mm). What is its width?
Rounded to the nearest tenth of an inch, the screen width is 63 inches.
There are two listeners in a training room. Listener One is 31 feet (9449 mm) from a loudspeaker and Listener Two is 17 feet (5182 mm) away.
What is the expected change in decibels at Listener One’s position when compared to Listener Two’s position? Round your answer to the nearest decibel.
= -5.218
An audio amplifier outputs 100 watts and then it is decreased to 50 watts.
What is the change in decibels?
-3.0
An audio amplifier outputs 75 watts and then it is decreased to 50 watts. What is the change in decibels?
-1.7
An audio amplifier outputs 10 watts and then it is decreased to 2 watts. What is the change in decibels?
-7
A presenter is playing a music CD from her laptop for two people in a room. Listener #1 is 2 meters away from the presenter.
Listener #2 is 15 meters away from the presenter. What is the expected loss in SPL at the listener #2 position?
-17.5
A presenter is speaking to a large audience. Listener #1 is 2 meters away from the presenter. Listener #2 is 15 meters away from the presenter. What is the expected gain in SPL at the listener #1 position?
17.5
Using a coverage angle of 90 degrees, a mounted loudspeaker height of 12 feet (3.7 meters), and the listener is seated, calculate the diameter of coverage.
16 feet (4.9 meters)
Using a coverage angle of 60 degrees, a mounted loudspeaker height of 12 feet (3.7 meters), and the listener is seated, calculate the diameter of coverage.
9 feet (2.7 meters)
Using a coverage angle of 70 degrees, a mounted loudspeaker height of 15 feet (4.8 meters), and the listener is seated, calculate the diameter of coverage.
15.4 feet (4.7 meters)
Calculate loudspeaker spacing for Edge to Edge, Partial Coverage and 50% Overlap if:
Loudspeaker height is 168 inches (426.72 cm)
Ear height is 48 inches (121.92 cm)
Coverage angle is 60 degrees
Edge to edge spacing = D = 138.56 inches or 351.96 cm
Partial coverage = D = 97.98 inches or 248.87 cm
50 percent overlap spacing = 69.28 inches or 175.98 cm
Calculate loudspeaker spacing if:
Loudspeaker height is 144 inches (365.76 cm)
Ear height is 48 inches (121.92 cm)
Coverage angle is 68 degrees
Edge to edge spacing = D = 72.66 inches D = 184.54 cm
Partial coverage spacing = D = 51.38 inches D = 130.49 cm
50 percent overlap spacing = 36.33 inches D = 92.27 cm
Calculate loudspeaker spacing for Edge to Edge, Partial Coverage and 50% Overlap if:
Loudspeaker height is 112 inches (284.48 cm)
Ear height is 62 inches (157.48 cm)
Coverage angle is 72 degrees
Edge to edge spacing = D = 72.66 inches D = 184.54 cm
Partial coverage spacing = D = 51.38 inches 130.49 cm
50 percent overlap spacing = D = 36.33 inches D = 92.27 cm
Calculate loudspeaker spacing for Edge to Edge, Partial Coverage and 50% Overlap if:
Loudspeaker height is 168 inches (426.72 cm)
Ear height is 48 inches (121 .92 cm)
Coverage angle is 60 degrees
Edge to edge spacing = D = 138.56 inches D = 351.96 cm
Partial coverage = D = 97.98 inches
50 percent overlap spacing = D = 69.28 inches
Calculate loudspeaker spacing for Edge to Edge, Partial Coverage and 50% Overlap if:
Loudspeaker height is 144 inches (365.76 cm)
Ear height is 48 inches (121 .92 cm)
Coverage angle is 68 degrees
Edge to edge spacing = D = 72.66 inches D = 184.54 cm
Partial coverage spacing = D = 51 .38 inches D =
130.49 cm
50 percent overlap spacing = D = 36.33 inches D =
92.27 cm
Calculate loudspeaker spacing for Edge to Edge, Partial Coverage and 50% Overlap if:
Loudspeaker height is 112 inches (284.48 cm)
Ear height is 62 inches (157.48 cm)
Coverage angle is 72 degrees
Edge to edge spacing = D = 72.66 inches D =
184.54 cm
Partial coverage spacing = D = 51 .38 inches
130.49 cm
50 percent overlap spacing = D
= 36.33 inches D =
92.27 cm
In a speaking facility, what is the required power to a loudspeaker if:
The farthest listener is 4 m from the loudspeaker.
The target sound pressure level at this position is 75 dB
The loudspeaker’s sensitivity is listed as 89 dB 1 w /1 m
6.37 watts are required
In a speaking facility, what is the required power to a loudspeaker if:
The farthest listener is 8 m from the loudspeaker
The target sound pressure level at this position is 70 dB
The loudspeaker’s sensitivity is listed as 89 dB 1 w /1 m
= 8.06 w
In a music performance facility, what is the required power to a
loudspeaker if:
- The farthest listener is 3 m from the loudspeaker.
- The target sound pressure level at this position is 75 dB
- The loudspeaker’s sensitivity is listed as 1 00 dB 1 w /1 m
= 2.85 w
In a speaking facility, what is the required power to a loudspeaker if:
- The farthest listener is 6 m from the loudspeaker
- The target sound pressure level at this position is 70 dB
- The loudspeaker’s sensitivity is listed as 93 dB 1 w /1 m
= 1.80 w
If the efficiency rating of an amplifier is 65% and the
amplifier draws 7 amperes (A) at 120 V of alternating
current (VAC) what is the heat load it generates?
2850 Btu/hr
According to best practices what is the safe working load
(SWL) requirement for overhead mounting of a 75 pound
(33.75 kg) projector?
375 pounds (168.75 kg)
Considering a 2400 watt lighting dimmer is available, the
design load for the system should NOT exceed
1920 watt
What is the recommended (highest) ambient lighting
level illuminating a front projections screen within a video
conferencing space?
5 footcandles (50 lux)
Why might you recommend to an AV client to set up a
dynamic host configuration protocol (DHCP) server
system?
Reduced possibility of address duplication
During the design phase of a project that has many
network-enabled AV devices. What will the IT team need
from the AV designer?
Bandwidth requirements