Free CTS Installation and Systems Integration Test 2 — Questions and Answers
Question 1: What should be done first if a control system’s touch screen is reported as locked, frozen, or otherwise not functioning?
- Remove the device, switch it out, and return it to the manufacturer for diagnostic checks
- Use a voltage meter to check for continuity, remove the motherboard and switch it out
- Reroute all systems to the nearest functioning system
- Check all connectors; confirm the screen is not in power saver mode (Correct answer)
Correct answer: Check all connectors; confirm the screen is not in power saver mode
If a control system's touchscreen is locked, frozen, or not functioning, the first step is to perform basic troubleshooting. This includes checking all connectors to ensure they are secure and confirming that the screen is not simply in a power saver or sleep mode. Often, a loose cable or a simple power cycle can resolve such issues before more complex diagnostics are needed.
Question 2: The customer demands a front projection system. What drawings should be acquired from the customer in order to pick the proper lens?
- Structural and electrical designs
- Floor layouts and wall detailing
- Reflected elevations and ceiling plans (Correct answer)
- Details on the building section and millwork
Correct answer: Reflected elevations and ceiling plans
To select the proper lens for a front projection system, an AV designer must have detailed information about the room's layout and dimensions. Reflected elevations and ceiling plans are essential as they provide critical data on ceiling height, screen placement, and potential obstructions. This information allows for accurate calculation of throw distance, image size, and lens shift, ensuring optimal projection performance.
Question 3: Noise in a space can distract users and reduce the efficacy of an audiovisual system. Which one of the following produces mechanical and structural noise?
- Reflected ceiling plans and elevations
- Why the VLAN is necessary
- A signal generator and signal analyzer
- HVAC fans, diffusers, and air handlers (Correct answer)
Correct answer: HVAC fans, diffusers, and air handlers
HVAC (Heating, Ventilation, and Air Conditioning) fans, diffusers, and air handlers are primary sources of mechanical and structural noise in a space. These components generate noise through air movement, fan operation, and vibrations transmitted through the building structure. Such noise can significantly impact the clarity and effectiveness of an audiovisual system, requiring careful acoustic design and mitigation strategies.
Question 4: What is the most likely cause of the projector's frequent power failure?
- Overcharging of the projector battery after prior use
- A fluctuation in the power outlet results in an electrical surge to the ground
- Insufficient bandwidth to support picture resolution
- Overheating caused by a filthy filter or a malfunctioning cooling fan (Correct answer)
Correct answer: Overheating caused by a filthy filter or a malfunctioning cooling fan
The most likely cause of a projector's frequent power failure is overheating, often due to a dirty filter or a malfunctioning cooling fan. Projectors generate significant heat, and if the cooling system is compromised, the projector will automatically shut down to prevent damage. Regular cleaning of filters and ensuring proper ventilation are crucial for projector longevity.
Question 5: What may be the cause of a laptop-connected projector not displaying a projected image?
- Ensure that the laptop is exclusively powered by its battery
- Ensure that the laptop's screen port has been activated using the appropriate function keys (Correct answer)
- Ensure the connection is RJ-45 over a HDBaseT-enabled network
- Ensure that you utilized an HD-15 to composite video output adaptor
Correct answer: Ensure that the laptop's screen port has been activated using the appropriate function keys
If a laptop-connected projector is not displaying an image, the most common cause is that the laptop's display output to an external monitor has not been activated. Laptops typically require specific function keys (e.g., Fn + F5, F7, or F8) to toggle between internal display, external display, or mirrored/extended modes. Activating the correct display output is essential for the projector to receive a signal.
Question 6: How does an AV system designer estimate the needed frequency response of an audio system?
- The frequency response should depend on the sort of applications the audio is designed to serve. (Correct answer)
- The audio system output frequency response should correspond to the frequency response of the audio source components.
- The designer should strive to produce as broad a frequency response as feasible given the project budget.
- The audio system's frequency response should be within the industry standard of 20Hz to 20kHz.
Correct answer: The frequency response should depend on the sort of applications the audio is designed to serve.
An AV system designer estimates the needed frequency response of an audio system based on the specific applications it is designed to serve. Different applications, such as speech reinforcement, background music, or high-fidelity concert sound, have varying requirements for bass, mid-range, and treble reproduction. Tailoring the frequency response ensures optimal performance for the intended use rather than simply aiming for the broadest possible range.
Question 7: The sound energy of a loudspeaker, for example, decreases as the listener travels away from it. Which formula would you use to calculate the decline in acoustic energy if the user traveled from 6 to 12 meters away from a sound source, using the inverse square law?
- dB = 20 log(6 meters = 12 meters)
- dB = 20 log(12 meters/6 meters)
- dB = 20 log(6 meters/12 meters) (Correct answer)
- dB = 20 log(6 meters × 12 meters)
Correct answer: dB = 20 log(6 meters/12 meters)
The inverse square law states that for every doubling of distance from a sound source, the sound pressure level decreases by 6 dB. To calculate the decline in acoustic energy when moving from 6 to 12 meters, the formula is dB = 20 log(D1/D2), where D1 is the initial distance and D2 is the final distance. Therefore, dB = 20 log(6 meters/12 meters) correctly represents this calculation.
Question 8: Which of the following scenarios is most likely to cause excessive high-frequency hiss in an audio system?
- Poor gain structure (Correct answer)
- Poor compression
- Noise gate thresholds set too low
- Source output gain is set too high
Correct answer: Poor gain structure
Poor gain structure is the most likely cause of excessive high-frequency hiss in an audio system. This occurs when gain levels are set too high at various points in the signal chain, amplifying inherent noise (hiss) present in electronic components. Proper gain staging ensures that the signal-to-noise ratio is optimized throughout the system, minimizing unwanted noise.
Question 9: Once the features of the system breakdown have been recognized, what is the suggested next step to restore normal operation?
- Logically divide the system in half, and discover which half has the failure
- Request that the user provide a more detailed description of the situation
- Replace the component that appears to have failed
- Examine the system to see if the problem is straightforward to solve and gather further information (Correct answer)
Correct answer: Examine the system to see if the problem is straightforward to solve and gather further information
Once a system breakdown's features are recognized, the suggested next step is to examine the system to see if the problem is straightforward to solve and gather further information. This initial assessment helps determine if it's a simple fix or requires more in-depth troubleshooting. It prevents immediately replacing components or dividing the system without a clear understanding of the issue.
Question 10: An amplifier can provide 100 watts at 2 ohms. How many 8-ohm speakers may be linked in parallel without surpassing the amplifier's capacity?
- 3
- 4 (Correct answer)
- 2
- 1
Correct answer: 4
To determine how many 8-ohm speakers can be linked in parallel without exceeding an amplifier's capacity of 100 watts at 2 ohms, first calculate the amplifier's maximum current. An amplifier rated for 2 ohms can handle a minimum impedance of 2 ohms. Four 8-ohm speakers wired in parallel result in a total impedance of 2 ohms (1 / (1/8 + 1/8 + 1/8 + 1/8) = 1 / (4/8) = 1 / (1/2) = 2 ohms), which matches the amplifier's minimum impedance rating.
Question 11: A technician sets up a condenser microphone. It isn't picking up sounds. What's the most likely reason?
- Phantom power is turned off (Correct answer)
- The microphone is malfunctioning
- The cable is excessively lengthy
- Pins 2 and 3 are switched at the XLR connection
Correct answer: Phantom power is turned off
Condenser microphones require external power, known as phantom power, to operate their internal active electronics. If a condenser microphone is not picking up sounds, the most common and likely reason is that phantom power, typically 48V DC supplied through the XLR cable, has not been enabled on the mixer or audio interface. Without this power, the microphone's capsule cannot convert sound waves into an electrical signal.
Free CTS Installation and Systems Integration Test 2
What should be done first if a control system’s touch screen is reported as locked, frozen, or otherwise not functioning?