Multichannel Reverberator Using Feedback Delay Network for Spatial Audio
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Solution Overview
Problem
Current multichannel reverberation technologies face inefficiencies in handling high numbers of sound sources and loudspeakers, lacking flexibility in source and receiver positioning, and are computationally costly, especially when trying to recreate realistic acoustic spaces with precise spatial cues.
Innovation Solution
A novel multichannel reverberator using a feedback delay network (FDN) that combines audio source signals and reverberated signals in delay lines, allowing for efficient generation of early reflections and late reverberation, with a scalable complexity independent of the number of audio sources, and maintaining spatial information for flexible loudspeaker configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If convolutional reverberators are used to reproduce acoustic spaces with high precision, then measurement precision and reliability are improved, but computational costs and device complexity increase linearly with the number of source and channel pairs
Solution Approach 1:
The patent segments the acoustic space reproduction into two distinct parts: early reflections (handled separately for each source-channel pair) and late reverberation (handled by a shared feedback delay network). This segmentation allows the computationally intensive convolution to be applied only where necessary (early reflections) while using a more efficient FDN approach for the late reverberation, thereby reducing overall computational complexity while maintaining precision.
Solution Approach 2:
The feedback delay network is designed to serve multiple sources and channels simultaneously through a universal set of delay lines and feedback matrices. Instead of having separate reverberation processors for each source-channel pair, a single FDN structure handles all late reverberation needs, making the system multi-functional and significantly reducing computational complexity while maintaining acoustic space reproduction precision.
2Adaptability or versatility
If multiple independent reverberators are instantiated to handle high numbers of channels, then adaptability and versatility are improved, but memory requirements and computational costs increase considerably
Solution Approach 1:
The patent merges multiple independent reverberation processing functions into a single feedback delay network that handles all channels simultaneously. The FDN uses shared delay lines, feedback matrices, and control parameters that can be configured for different loudspeaker setups, thereby maintaining adaptability while significantly reducing memory requirements compared to having separate reverberators for each channel.
Solution Approach 2:
The system employs dynamic configuration capabilities where the FDN can be adapted to different loudspeaker setups and spatial arrangements through programmable delay times, feedback gains, and mixing parameters. This dynamic adaptability allows the same hardware/software structure to serve multiple configurations without requiring separate instantiated reverberators for each setup, reducing memory requirements while maintaining versatility.
3Ease of operation
If conventional reverberation algorithms are used, then ease of operation is maintained, but flexibility in coping with arbitrary source inputs and loudspeaker setups is reduced
Solution Approach 1:
The feedback delay network is designed as a universal processor that can handle arbitrary numbers of input sources and output channels through configurable delay lines and feedback matrices. The system maintains ease of operation by providing a unified control interface while internally adapting to different source and loudspeaker configurations, thereby achieving both ease of use and high flexibility.
Solution Approach 2:
The system provides dynamic adaptability through programmable parameters that allow the FDN to be configured for different source inputs and loudspeaker setups. Users can adjust delay times, feedback gains, and mixing ratios to match specific acoustic environments and reproduction configurations, maintaining ease of operation while achieving high flexibility with arbitrary configurations.
Data Source
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AI summary
An apparatus for generating a first multitude of output signals based on at least one audio source signal comprising a delay network and a feedback processor. The delay network comprises a second multitude of delay paths, each delay path having a delay line and an attenuation filter. Each delay line is configured for delaying delay line input signals and for combining the at least one audio source signal and a reverberated audio signal to obtain a combined signal, wherein the attenuation filter of a delay path is configured for filtering the combined signal from the delay line of the delay path to obtain an output signal. The first multitude of output signals comprises the output signal. The feedback processor is configured for reverberating the first multitude of output signals to obtain a third multitude of the reverberated audio signals comprising the reverberated audio signal.