Acoustic Enclosure with Waveguide for Directivity Control
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Solution Overview
Problem
Existing public address systems face challenges in achieving homogeneous sound levels and quality across the audience area, particularly in low frequencies, due to limited directivity and resonance issues.
Innovation Solution
The acoustic enclosure features a volumetric shape with front, rear, and lateral sound sources, along with a sound waveguide that directs lateral sound emissions to the sides and rear, enhancing directivity and reducing resonance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If sound diffusion devices are used in low frequencies, then sound coverage is achieved, but directivity is lost and sound pollutes areas to be avoided
Solution Approach 1:
The sound diffusion device is segmented into multiple independent sound sources (first sound source, second sound source, third sound source) positioned at different locations and orientations. This segmentation allows each source to contribute to different spatial zones, achieving broad coverage while maintaining directional control through individual amplitude and phase adjustment of each source.
Solution Approach 2:
The invention transitions from traditional single-axis sound diffusion to three-dimensional sound distribution by positioning sound sources at different spatial coordinates (front, rear, and lateral positions). The third sound source is specifically oriented laterally to provide coverage in previously underserved horizontal directions, creating omnidirectional yet controlled sound distribution.
2Object-generated harmful factors
If electronic control of amplitude and phase is applied to multiple sound sources, then directivity control is improved, but device complexity increases
Solution Approach 1:
The electronic control system is designed to be dynamically adjustable, allowing real-time modification of amplitude and phase parameters for each sound source. This dynamic capability enables adaptation to different acoustic environments and directivity requirements without requiring physical reconfiguration of the device structure.
Solution Approach 2:
The invention utilizes parameter changes in the electronic control system, specifically adjusting amplitude ratios and phase differences between sound sources to achieve desired directivity patterns. By varying these parameters, the system can switch between different radiation patterns (omnidirectional, directional, focused) without changing the physical configuration.
3Object-generated harmful factors
If sound sources are arranged in front-to-back alignment, then directivity is achieved, but summation of sound radiation is not optimal
Solution Approach 1:
The invention merges multiple sound sources (front, rear, and lateral) into a unified three-dimensional sound distribution system. By combining the radiations from all three sources with proper phase and amplitude coordination, the system achieves constructive interference in desired directions while minimizing destructive interference, thereby optimizing overall sound radiation efficiency.
Solution Approach 2:
The electronic control system acts as an intermediary that coordinates the output of multiple sound sources. It processes the audio signal and distributes it to each sound source with appropriate amplitude scaling and phase shifting, ensuring that the combined radiation pattern achieves both directivity and optimal summation without requiring complex physical arrangements.
4Object-generated harmful factors
If DSP settings are adjusted for directivity control, then radiation pattern is adapted, but frequency localization of directivity control occurs
Solution Approach 1:
The invention applies local quality by assigning different amplitude and phase characteristics to each sound source based on its spatial position. The first and second sound sources (front and rear) are configured with specific phase relationships to control forward and rearward radiation, while the third lateral sound source is configured to provide uniform lateral coverage, creating locally optimized radiation patterns that collectively achieve broadband directivity control.
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 configuration improves sound directivity and homogeneity across the audience area, reduces resonance and reverberation, and allows for better control of sound radiation patterns through electronic amplitude and phase control.
Implementation Method 1
at least one sound waveguide, said waveguide being positioned in front of the at least one lateral acoustic source so as to occlude the sound flux emitted by said lateral acoustic source in the main lateral source emission direction
Implementation Method 2
Electronic control of the amplitude and phase of the sound sources makes it possible to adapt the radiation pattern, and thus the directivity of the sound diffusion devices
Implementation Method 3
Summation of the sound radiation from the different devices means the superposition of these radiations, creating constructive or destructive zones
Implementation Method 4
can also excite the resonance modes of rooms and create disturbing reverberation on the audience
Implementation Method 5
reduces resonance and reverberation
Data Source
AI summary
A loudspeaker enclosure comprising a plurality of acoustic sources and having controlled broad-band directivity.