Acoustics and sound systems Part 2

Sound systems :

Fundamentals of sound system design and operation.

Theoretical tools and models associated with the design of sound systems for large spaces.

Design of advanced broadcast system layouts for auditoriums.

Optimising the performance of PA systems by measuring acoustic parameters used in sound systems.

B 1: Reminder of acoustic sources

Principles of radiation from acoustic sources: wave surfaces, free field decay law, directivity function, embedded sources, notion of near field and far field, radiation impedance, etc.

Omnidirectional radiation: the point source

Interference from 2 point sources, introduction to the notion of directivity, application to cardioid subs

Directional radiation: the recessed circular planar piston

The source line

B 2 : Sound reinforcement loudspeakers

Types of transduction: electrodynamic, electrostatic, piezoelectric

The electrodynamic loudspeaker: magnetic aspect, membranes and suspensions, equivalent electrical diagram and exploitable bandwidth

Baffles: flat baffles, closed enclosures: resonance frequency, efficiency, standing waves, diffraction effects.

Bass reflex

Multi-channel loudspeakers: bass speaker (usual characteristics), sub-bass speaker (floor effect), treble speaker (compression chamber, horns).

Filtering

Technical characteristics of loudspeakers

Distribution processors and amplification

B 3: Introduction to power sound systems, elements of sound design

Outdoor system :

Free field decay and pressure level calculations, sound coverage

Acoustic gain and acoustic response

Indoor system

Acoustic source in a room: direct field, reverberant field, critical distance

Elements of sound design: direct field and reverberant field coverage, critical distance, distributed multidiffusion, Haas effect

C: sound system conception and design

In-depth study of acoustic modelling and simulation tools for listening rooms and large spaces.

In-depth study of sound coverage modelling tools and the expected characteristics of sound systems.

Audit of a real venue and assessment of constraints.

Drafting of specifications and a technical file presenting different solutions and their characteristics.

FSMS 2

Continuous assessment, followed by the submission of a personal report on the design of a system adapted to the constraints of the room and the project.

2 Written tests:

- Acoustics

- Sound