Hemispherical Loudspeaker Array for Vehicle Immersive Audio

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Solution Overview

Problem

Conventional loudspeaker arrangements in vehicles fail to effectively create authentic two-dimensional (2D) and three-dimensional (3D) audio environments due to directional gaps and limitations in covering lateral and rear passenger positions, especially when trying to render sound sources from the side and rear.

Innovation Solution

A loudspeaker array with a multiplicity of array loudspeakers mounted on a rigid hemisphere enclosing an acoustic volume, combined with additional loudspeakers at specific levels and positions within the car interior, including headrest and ceiling installations, to enhance sound coverage and create immersive acoustics through advanced digital signal processing and beamforming techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional loudspeaker arrangements are used with speakers distributed throughout the interior, then various audio sources can be provided at various positions, but directional gaps occur and lateral and rear passenger positions are not adequately covered

Engineering Contradiction:
Improvecoverage of lateral and rear positionsVSAvoiddirectional gaps in sound coverage
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent transitions from conventional planar loudspeaker arrangements to a three-dimensional spherical array configuration. Multiple loudspeakers are positioned at different spatial coordinates (x, y, z) forming a spherical geometry, enabling sound radiation in all directions including lateral and rear positions. This dimensional expansion eliminates directional gaps by providing omnidirectional coverage that conventional 2D arrangements cannot achieve.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The spherical loudspeaker array is divided into multiple independent loudspeaker units positioned at specific locations on the sphere surface. Each loudspeaker acts as an independent element that can be individually controlled through beamforming techniques. This segmentation allows precise directional control of sound waves and enables the system to address specific spatial zones (lateral, rear, front) independently, resolving the coverage gaps.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If a spherical loudspeaker array is implemented to eliminate directional gaps, then coverage of all passenger positions is improved, but the device complexity increases

Engineering Contradiction:
Improveomnidirectional sound coverageVSAvoidnumber of loudspeakers and spatial arrangement
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The spherical loudspeaker array serves multiple functions simultaneously: it provides omnidirectional sound coverage, enables directional beamforming, supports virtual acoustic source rendering, and accommodates various seating positions. This multi-functionality justifies the increased complexity by delivering comprehensive audio coverage that conventional single-function arrangements cannot achieve.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system changes the spatial parameters of loudspeaker placement from conventional planar distributions to three-dimensional spherical coordinates. By adjusting the positional parameters (x, y, z) and utilizing spherical geometry, the system achieves omnidirectional coverage with a structured arrangement that, while complex, provides systematic control over sound propagation in all directions.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If additional loudspeakers are installed at multiple levels and positions including headrest and ceiling, then sound coverage and immersive acoustics are enhanced, but the manufacturing and installation complexity increases

Engineering Contradiction:
Improveimmersive audio experienceVSAvoidinstallation of multiple loudspeaker positions
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The loudspeaker system incorporates nested positioning where headrest loudspeakers are integrated into seat structures, ceiling loudspeakers are mounted within the vehicle ceiling framework, and spherical array elements are positioned within the passenger compartment volume. This nested arrangement allows multiple loudspeaker systems to coexist in the limited vehicle space without requiring separate dedicated structures for each component.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The implementation uses a spherical geometric configuration for the main loudspeaker array, which provides natural omnidirectional coverage. This curved spherical arrangement simplifies the spatial relationships between loudspeakers compared to complex polyhedral or irregular arrangements, as the spherical geometry inherently provides uniform angular distribution and simplifies beamforming calculations.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP3185580B1Loudspeaker arrangement for a car interior comprising a hemispherical loudspeaker array
Publication Date: 2022.03.23 HARMAN BECKER AUTOMOTIVE SYST GMBH
  • EP3185580B1 patent drawingFigure 1
  • EP3185580B1 patent drawingFigure 2
  • EP3185580B1 patent drawingFigure 3~4

AI summary

Disclosed is a loudspeaker array with a multiplicity of array loudspeakers, wherein the array loudspeakers are mounted in the surface of a rigid hemisphere that encloses an acoustic volume, and are regularly or quasi-regularly distributed over the surface of the hemisphere, and a loudspeaker arrangement including such array.