CEA CEA Live Sound & Event Production 1 — Questions and Answers
Question 1: What is 'feedback' in a live sound reinforcement system, and what is its primary cause?
- Distortion caused by overdriving the power amplifier
- A sustained howl or ring caused by a microphone picking up its own amplified output from a speaker (Correct answer)
- Low-frequency rumble from a poorly isolated stage
- Comb filtering between two adjacent microphones
Correct answer: A sustained howl or ring caused by a microphone picking up its own amplified output from a speaker
Acoustic feedback occurs when a microphone is positioned so it captures the sound from a loudspeaker it feeds, creating a closed loop that results in sustained oscillation.
Question 2: In live sound, what does the 'front-of-house' (FOH) position refer to?
- The mixing position located offstage in the wings
- The main mixing console and operator position facing the stage from the audience area (Correct answer)
- The monitor engineer's position at the side of the stage
- The area behind the main speaker clusters
Correct answer: The main mixing console and operator position facing the stage from the audience area
FOH is the primary mixing position situated in the audience area, where the engineer controls the main house PA system as heard by the audience.
Question 3: What is the purpose of a monitor mix in a live sound environment?
- To provide a delayed version of the FOH mix for audience members in the back
- To give performers on stage a customized mix of what they need to hear to perform (Correct answer)
- To drive subwoofers separately from the main PA
- To record a dry signal for post-production
Correct answer: To give performers on stage a customized mix of what they need to hear to perform
Stage monitor mixes are tailored feeds sent to wedges or in-ear monitors so each performer hears a personalized blend of vocals, instruments, and click tracks.
Question 4: What is 'gain before feedback' in a live sound context?
- The amount of gain applied by the FOH EQ before the signal reaches the amplifier
- The maximum amount of gain achievable on a microphone channel before the system breaks into feedback (Correct answer)
- The headroom available above 0 dBFS on a digital console
- The preamp gain setting that optimizes the signal-to-noise ratio
Correct answer: The maximum amount of gain achievable on a microphone channel before the system breaks into feedback
Gain before feedback describes how much amplification a live system can apply to a microphone before the loop gain exceeds unity and feedback begins.
Question 5: What is a 'line array' speaker system, and what is its key acoustic advantage in large venues?
- A single large horn speaker with wide horizontal dispersion
- Vertically arrayed speaker elements that couple coherently to achieve controlled, long-throw coverage with reduced splay (Correct answer)
- A cardioid subwoofer array designed to cancel rear energy
- A series of delay speakers placed throughout a large audience area
Correct answer: Vertically arrayed speaker elements that couple coherently to achieve controlled, long-throw coverage with reduced splay
A line array consists of multiple speaker modules stacked vertically that act as a coherent line source, providing consistent sound pressure level over long distances with a narrow vertical dispersion.
Question 6: In live event production, what does 'rider' refer to?
- The stagehands responsible for setting up the PA
- A document provided by the artist specifying technical and hospitality requirements for a show (Correct answer)
- The delay setting applied to the PA to time-align it with the stage
- The rental contract for equipment provided by a vendor
Correct answer: A document provided by the artist specifying technical and hospitality requirements for a show
A technical rider is an addendum to the performance contract detailing the artist's required sound system specifications, stage plot, input list, and backline requirements.
CEA CEA Live Sound & Event Production 1
What is 'feedback' in a live sound reinforcement system, and what is its primary cause?