Individual Sound Zone Volume Control via Frequency Segregation

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Solution Overview

Problem

Existing individual sound zone systems lack independent volume control for each listening position, leading to inconsistent volume preferences and compromised audio quality when adjusting volume settings.

Innovation Solution

Implementing a system with headrest and height speakers for mid and high frequencies, and low pass filters for bass frequencies, allowing users to set distinct volume preferences for each sound zone through separate gain adjustments, while maintaining stereo quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a master volume control is used for all sound zones, then the system is simple to operate, but listeners cannot set individual volume preferences for each sound zone

Engineering Contradiction:
Improvevolume control capabilityVSAvoidindividual volume preference
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The volume control function is segmented from a single master control into multiple independent zone-specific controls. Each sound zone (front left, front right, rear left, rear right) has its own volume control button, allowing individual listeners to adjust volume independently while maintaining system simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A processor acts as an intermediary between the volume control buttons and the amplifiers. The processor receives zone-specific volume inputs, combines them with the master volume setting, and generates appropriate gain adjustments for each channel, enabling individual control without complex direct amplifier connections.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If volume is adjusted in individual sound zones, then individual volume preference is achieved, but stereo sound quality is compromised

Engineering Contradiction:
Improveindividual volume preferenceVSAvoidstereo sound quality
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system changes the parameter being controlled from direct amplifier gain to processor-level volume adjustments. By modifying the audio signal parameters in the processor before amplification, the system maintains stereo integrity while allowing zone-specific volume preferences through mathematical operations on the audio signal.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system uses feedback from multiple microphones to monitor the actual sound field in each zone. This feedback is processed to determine appropriate volume adjustments that maintain stereo quality, allowing the system to adapt volume control based on real-time acoustic conditions rather than simple gain changes.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If separate volume controls are implemented for each sound zone, then individual volume preference is achieved, but the system complexity increases

Engineering Contradiction:
Improveindividual volume preferenceVSAvoidcontrol system structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The processor is designed as a universal control unit that handles multiple functions: master volume adjustment, zone-specific volume control, stereo processing, and feedback analysis. This multi-functional approach consolidates what would otherwise require separate control systems for each zone, reducing overall system complexity.

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

Solution Approach 2:

The system merges the master volume control with individual zone volume controls into a unified processing architecture. Rather than having separate control circuits for each zone, the processor integrates all volume control functions, combining master and zone-specific adjustments through a single coherent system that reduces component count and complexity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3393141B1Volume control for individual sound zones
Publication Date: 2020.01.29 HARMAN INT IND INC
  • EP3393141B1 patent drawingFigure 1
  • EP3393141B1 patent drawingFigure 2
  • EP3393141B1 patent drawingFigure 3

AI summary

A system and method for applying an individual volume control setting to individual sound zones as set by a user. When the individual volume control setting differs from a master volume control setting, the individual volume control setting is applied to the low frequency component of the audio signal. Headrest and optional height speakers for each individual sound zone's independent volume setting are applied to the mid and high frequency components of the audio signal.