Multi-channel renderer for loudspeaker spatial sound
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing audio systems, particularly those using wave field synthesis, face challenges in providing optimal spatial sound reproduction due to high computational demands and artifacts caused by incorrect loudspeaker arrangements, leading to suboptimal audio quality and authenticity in multimedia systems.
Innovation Solution
An apparatus and method for calculating drive coefficients for loudspeakers using different subdriving coefficients based on specific calculation rules for virtual sources inside and outside the loudspeaker arrangement, with a variable transition zone to reduce artifacts and improve audio quality by accounting for the perceptual behavior of virtual sources at different distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If wave field synthesis is used to achieve natural spatial sound reproduction across a great area, then spatial sound quality is improved, but computational power and transfer rates are excessively demanded
Solution Approach 1:
The patent segments the reproduction space into multiple zones (first reproduction space, second reproduction space, third reproduction space) with different acoustic characteristics. Each zone is processed independently with appropriate transfer functions, reducing the overall computational complexity compared to processing the entire space uniformly with traditional wave field synthesis.
Solution Approach 2:
Different transfer functions are applied to different spatial zones based on their specific acoustic properties. The first transfer function is used for the first reproduction space, the second for the second reproduction space, and the third for the third reproduction space. This localized approach optimizes computational resources by tailoring processing to each zone's requirements rather than using a single complex model for all spaces.
2Productivity
If traditional multi-channel loudspeaker reproduction is used, then computational requirements are reduced, but the listener position and loudspeaker arrangement are fixed, limiting the reproduction area
Solution Approach 1:
The system dynamically selects and switches between different transfer functions based on the listener's position and the active reproduction space. The transfer function selection is not fixed but adapts in real-time to changing spatial conditions, enabling the system to maintain computational efficiency while covering multiple reproduction areas.
Solution Approach 2:
The patent implements a universal audio reproduction system that can handle multiple reproduction spaces (first, second, and third reproduction spaces) with different acoustic characteristics using a single integrated apparatus. The system can switch between different transfer functions to serve multiple purposes and spatial configurations, making it versatile across different listening environments.
3Measurement precision
If wave field synthesis is applied with irregular environment properties, then spatial sound reproduction is achieved, but artifacts occur when environment properties change or do not match
Solution Approach 1:
The system changes the transfer function parameters based on the detected environment type and reproduction space. Different transfer functions are designed with parameters optimized for specific acoustic environments, allowing the system to adapt to varying environmental properties and maintain reliable audio quality across different conditions without artifacts.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An apparatus for calculating driving coefficients for loudspeakers of a loudspeaker arrangement for an audio signal associated with a virtual source comprises a multi-channel Tenderer. The multi-channel Tenderer calculates first subdriving coefficients for loudspeakers of the loudspeaker arrangement according to a first calculation rule, calculates second subdriving coefficients for the same loudspeakers according to a second calculation rule and calculates driving coefficients for the same loudspeakers based on the first subdriving coefficients and the second subdriving coefficients, if a position of the virtual source is located within an inner area of a loudspeaker transition zone. Further, the multi-channel renderer (110) calculates second subdriving coefficients for loudspeakers (410) of the loudspeaker arrangement according to the second calculation rule, calculates third subdriving coefficients for the same loudspeakers (410) according to a third calculation rule and calculates driving coefficients (112) for the same loudspeakers (410) based on the second subdriving coefficients and the third subdriving coefficients, if a position (102) of the virtual source is located within an outer area (434) of the loudspeaker transition zone (430). Further, an apparatus for providing drive signals for loudspeakers of a loudspeaker arrangement based on an audio signal associated with a virtual source comprises a loudspeaker determiner (810) and a multi-channel renderer (820). The loudspeaker determiner (810) determines a group of relevant loudspeakers (812) of the loudspeaker arrangement located within a variable angular range around a position (802) of the virtual source. The variable angular range is based on a distance between the position (802) of the virtual source and a predefined listener position (804). The multi-channel renderer (820) calculates driving coefficients for the determined group of relevant loudspeakers (812). Further, the multi-channel renderer (820) provides drive signals (822) to the group of relevant loudspeakers (812) based on the calculated driving coefficients and the audio signal (806) of the virtual source without providing drive signals of the virtual source to other loudspeakers than the loudspeakers of the group of relevant loudspeakers (812).