Wave Field Synthesis Sound Transducer Array for Uniform Audience Coverage

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Solution Overview

Problem

Conventional PA systems struggle to maintain consistent sound pressure levels across large audience areas, especially at distances from the sound transducer arrangement, due to the limitations of line arrays and the inefficiency of individual dynamic speakers in the bass range, leading to reduced sound quality and increased noise interference.

Innovation Solution

A method using a two-dimensional arrangement of sound transducers based on wave field synthesis, where multiple virtual sound sources with the same signal content are generated at equidistant positions to create a narrow radiation angle, allowing for efficient sound pressure distribution and minimizing comb filter effects, while adjusting signal levels and equalization to optimize sound coverage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If line arrays are used to cover large audience areas, then sound pressure is maintained at distant regions, but sound pressure decreases with distance (by about 3 dB for each doubling of distance)

Engineering Contradiction:

Improveaudience area coverageVSAvoidsound pressure level

Core Design Contradiction:

Area of stationary objectVSStress or pressure

Solution Approach 1:

The system divides the sound field into multiple independent wave fronts, each originating from a virtual sound source positioned at different locations. Each wave front is generated by a specific subset of sound transducers, allowing independent control and optimization of sound pressure in different spatial regions. This segmentation enables maintaining high sound pressure levels across the entire audience area without the rapid decay associated with conventional line arrays.

Inventive Principle:

Principle #1Segmentation

2Ease of operation

If virtual sound sources are positioned at equidistant positions to create narrow radiation angle, then directional control is improved, but comb filter effects increase

Engineering Contradiction:

Improvedirectional controlVSAvoidcomb filter effects

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The system assigns different signal characteristics to different virtual sound sources based on their specific positions and the spatial requirements of the audience area. Each virtual sound source receives customized signal parameters (phase, amplitude, equalization) optimized for its location, allowing narrow radiation angles for directional control while minimizing comb filter effects through localized signal optimization rather than uniform treatment of all sources.

Inventive Principle:

Principle #3Local quality

3Stress or pressure

If multiple virtual sound sources with the same signal content are generated, then sound pressure distribution is improved, but signal processing complexity increases

Engineering Contradiction:

Improvesound pressure distributionVSAvoidsignal processing complexity

Core Design Contradiction:

Stress or pressureVSDevice complexity

Solution Approach 1:

The system pre-calculates and stores the signal characteristics (phase, amplitude, equalization parameters) for each virtual sound source before actual sound generation. This preliminary preparation allows the system to efficiently generate multiple wave fronts with the same signal content without real-time complex processing, reducing the computational burden during operation while maintaining uniform sound pressure distribution across the audience area.

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach ensures consistent sound pressure levels across the audience area, reduces noise interference, and enhances sound quality by maintaining high efficiency even at distances, with improved directional control and reduced energy loss in the bass range.

Implementation Method 1

each virtual sound source behind this arrangement, is physically reconstructed from a plurality of individual transducers according to Huygens' principle

Methodology Applied

Scientific EffectHuygens' principle:

Implementation Method 2

the wave field synthesis method described by A. J. Berkhout in 1988

Methodology Applied

Scientific EffectWave field synthesis:

Data Source

PatentUS9843864B2Method for operating an arrangement of sound transducers according to the wave field synthesis principle

Publication Date: 2017.12.12 HOLOPLOT GMBH

AI summary

A method and a device for operating an arrangement of sound transducers according to the wave-field synthesis principle. In order to supply an extended audience region with the same signal, the same signal content is generated by at least two virtual sound sources, which are arranged such that the wavefronts thereof are directed only onto a part audience area, rather than generating only a single beam extending over the entire audience area. The wavefronts of the distributed virtual sound sources add up vectorially in the plane of the arrangement of sound transducers, whereby the effectiveness of the sound generation is increased.