Virtual Top-Channel Surround Mixing for Off-Sweet-Spot 3D Audio

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Solution Overview

Problem

Existing multi-channel speaker systems without top rear speakers, such as 5.1.2 or 7.1.2 systems, fail to provide a full 360-degree surround sound experience due to the lack of height effects, and virtual sound features degrade significantly when listeners are away from the sweet spot.

Innovation Solution

A multi-channel audio processing method that applies crosstalk cancellation and head-related transfer functions to top channel signals, mixing them with surround channel signals to create virtual top speakers, enhancing the sound experience without additional physical speakers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple audio channels are processed separately through different audio processing chains, then each channel can be optimized independently, but the system complexity and processing delay increase

Engineering Contradiction:
Improvechannel optimization flexibilityVSAvoidprocessing system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The audio processing system divides the multichannel audio signal into separate channels (first audio channel, second audio channel, etc.) and processes each channel independently through dedicated audio processing chains. This segmentation allows independent optimization of each channel's processing parameters while maintaining manageable system complexity through modular architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a universal audio processing framework where a single system architecture can handle multiple audio channels with different processing requirements. The audio processing apparatus can accommodate various channel configurations (stereo, surround sound, etc.) and apply different processing chains to each channel, providing multi-functionality without requiring completely separate systems.

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

2Manufacturing precision

If audio signals are processed through multiple processing stages, then processing flexibility and quality improvement are achieved, but processing time and latency increase

Engineering Contradiction:
Improveaudio processing qualityVSAvoidprocessing delay
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary audio processing operations (such as channel separation, initial filtering, and feature extraction) before the main audio rendering or playback stage. By preparing and pre-processing audio channels in advance, the system optimizes processing quality while minimizing real-time latency during actual audio delivery.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The audio processing system dynamically adjusts processing parameters and stages based on real-time conditions and audio content characteristics. The system can adaptively select which processing stages to apply and adjust processing intensity to balance quality optimization with latency requirements, making the processing pipeline flexible rather than fixed.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If separate audio processing chains are used for different channels, then channel-specific optimization is enabled, but hardware resources and system cost increase

Engineering Contradiction:
Improvechannel-specific optimizationVSAvoidhardware resource consumption
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent merges common audio processing functions and algorithms across different channels into shared processing resources. Instead of implementing completely separate processing chains for each channel, the system combines common operations (such as universal filtering algorithms, shared DSP cores, and common audio formats) to achieve channel-specific optimization while reducing overall hardware resource consumption through resource sharing and consolidation.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4399883B1Multi-channel audio processing method, system and stereo apparatus
Publication Date: 2026.05.06 HARMAN INT IND INC
  • EP4399883B1 patent drawingFigure 1~2
  • EP4399883B1 patent drawingFigure 3~4
  • EP4399883B1 patent drawingFigure 5~6

AI summary

A method for processing multi-channel audio signals, a system for processing multi-channel audio signals and a stereo apparatus comprising such a system. The multi-channel audio processing method comprises: receiving multi-channel audio signals from an external audio source, the multi-channel audio signals comprises a pair of surround channel signals and a pair of top channel signals; applying a crosstalk cancellation process in consideration of a head-related transfer function to the pair of top channel signals, so as to produce a pair of processed top channel signals, the head-related transfer function is configured to provide an elevation angle; mixing the pair of processed top channel signals, respectively, with the pair of surround channel signals, so as to produce a pair of mixed surround channel signals; providing the pair of mixed surround channel signals, respectively, to a pair of surround speakers.