Speaker Array Equalization Using Segmented Frequency Response Analysis

Solution Overview

Problem

Current sound reproduction systems in cinema environments face challenges in accurately equalizing speakers across multiple channels and arrays, leading to suboptimal frequency response and bass management, particularly in complex configurations with increasing numbers of channels and sophisticated sound reproduction modes.

Innovation Solution

The system determines individual frequency responses for each speaker and array, using equalization coefficients to modify stimulus signals, and employs bass management by directing low-frequency energy to sub-woofers based on distance, ensuring accurate frequency content modification and acoustic energy distribution to simulate realistic three-dimensional sound environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional equalization methods are used for speaker arrays, then the setup process is simple, but the frequency response accuracy and timbral matching deteriorate

Engineering Contradiction:

Improvefrequency response accuracyVSAvoidequalization process complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The equalization process is divided into two distinct stages: individual speaker equalization and array equalization. Individual speaker equalization determines equalization coefficients for each speaker based on its specific frequency response characteristics. Array equalization then determines additional coefficients to account for interactions between speakers in the array. This segmentation allows each stage to optimize for its specific purpose, improving overall frequency response accuracy while keeping each individual process manageable.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Individual speaker equalization is performed as a preliminary step before array equalization. By first equalizing each speaker individually to achieve accurate frequency response, the foundation is laid for subsequent array-level adjustments. This preliminary action ensures that each speaker contributes optimally to the overall array performance, improving timbral matching and reducing artifacts.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If individual speaker equalization is performed, then frequency response accuracy improves, but processing time and computational resources increase

Engineering Contradiction:

Improvespeaker equalization precisionVSAvoidequalization processing time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The equalization process is divided into two distinct stages: individual speaker equalization and array equalization. Individual speaker equalization determines equalization coefficients for each speaker based on its specific frequency response characteristics. Array equalization then determines additional coefficients to account for interactions between speakers in the array. This segmentation allows each stage to optimize for its specific purpose, improving overall frequency response accuracy while keeping each individual process manageable.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system changes the parameters being optimized at different stages. Individual speaker equalization focuses on frequency response accuracy for each speaker. Array equalization then adjusts parameters to optimize overall array performance, including timbral matching and artifact reduction. This parameter changes approach allows efficient optimization at each stage without requiring exhaustive processing of all parameters simultaneously.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If bass management directs low-frequency energy to sub-woofers, then acoustic energy distribution improves, but system complexity increases

Engineering Contradiction:

Improveacoustic energy distributionVSAvoidbass management system complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The bass management system serves multiple functions: it directs low-frequency energy from individual speakers to appropriate sub-woofers, manages the frequency responses of multiple sub-woofers, and integrates with both individual and array equalization processes. This multi-functionality improves acoustic energy distribution across the listening environment while consolidating control within the existing sound reproduction system architecture.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The bass management system acts as an intermediary between the individual speakers/arrays and the sub-woofers. It receives audio signals from speakers, processes the low-frequency energy components, and directs them to appropriate sub-woofers based on spatial and frequency characteristics. This intermediary role simplifies the overall system by providing a centralized control mechanism for bass distribution.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9118999B2Equalization of speaker arrays

Publication Date: 2015.08.25 DOLBY LABORATORIES LICENSING CORP

AI summary

Methods and apparatus are described by which equalization and/or bass management of speakers in a sound reproduction system may be accomplished.