Quiz: System Structure – Holophonix Learning Platform

1. Sound reinforcement system

3

Select the correct answers.

A sound reinforcement system works exclusively by reflection off the room walls.
A sound reinforcement system is placed between the performers and the audience.
A sound reinforcement system works on the same principle as light, by reflection.

2. Traditional front-of-house system

2

A traditional sound reinforcement front-of-house system is composed of

A network of loudspeakers distributed behind the performers.
Main loudspeakers to the left and right of the performers’ stage area: a stereophonic system.

3. Basic structure of a spatialized sound system

5

A spatialization sound system is:

composed of an immersive system formed by a network of loudspeakers surrounding the audience emitting the same signal.
composed of a main front-of-house system (FOH) located behind the stage.
composed of an immersive system formed by a network of loudspeakers surrounding the audience, emitting specific signals to reproduce localizable sound sources.
composed of a main front-of-house system (FOH) distributed between the artists and the audience.
composed of an immersive system formed by a network of loudspeakers at the center of the audience emitting the same signal.

4. Front-fills

3

Front-fill loudspeakers

complement the main diffusion system in order to cover the audience area in front of the stage.
are used to allow performers to hear themselves better.
form a loudspeaker array located at the front of the stage.

5. A stereophonic system

4

A stereophonic system:

can have more than 2 loudspeakers.
reproduces a centered virtual source if the signal is the same in both loudspeakers and if the listener is at the sweet spot.
reproduces a centered virtual source if the signal is the same in both loudspeakers regardless of the listener’s position.
requires that the listener, to perceive the original sound scene, be at equal distances from the loudspeakers with an angle of plus or minus 30° on either side of the frontal axis.

6. Multichannel spatialization

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Multichannel spatialization:

allows better frequency reproduction
can extend the listening area to faithfully reproduce a sound scene.
improves intelligibility.
unlike stereo alone, allows better visual correlation with a live source.

7. Visual correlation

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Visual correlation with an amplified sound source (the listener is in the audience area)

can be preserved with a traditional stereo system if the listener is positioned in front of the source.
is not possible with a sound field reproduction system such as Wave Field Synthesis (WFS).
can be preserved with a traditional stereo system if the listener is positioned at the “sweet-spot”.
can be improved with a multichannel diffusion system enabling the spatialization of this source.
means that the sound and image perceived are localized at the same place.

8. Sweet spot

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For a spatialized multichannel playback system, the sweet spot:

the position of the farthest loudspeaker.
is the ideal listening point for perceiving a spatialized sound scene.
is the reference point in space (center of a coordinate frame) used by a spatialization algorithm to identify the coordinates of sound sources and loudspeakers.

9. Positioning of a sound source relative to the system

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Sources spatialized on an immersive spatialization system:

are localized at the periphery or beyond the loudspeaker system.
must be localized inside the system, i.e. within the listening area.

10. Spatialization algorithms

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Spatialization algorithms are

individual listening systems.
spatialization by signal matrixing: amplitude panning and KNN.
Spatialization by acoustic field reconstruction: wavefront synthesis (WFS) and Ambisonics (HOA).
Virtualization of the acoustic field on 2 channels: binaural and transaural rendering.

Structure of Sound Diffusion Systems

Quiz: System Structure Quiz