Virtual Soundstage via Null Steering in Compact Speaker Arrays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In automotive vehicles, creating a wide soundstage with a compelling listening experience is challenging due to space, weight, and cost constraints, as well as the need for complex signal processing with fewer speakers than in rooms or theaters, requiring a solution to generate virtual sound sources using a compact speaker array with minimal processing.
Innovation Solution
A system with a compact speaker array of at least two speakers centrally positioned, along with a signal processing unit that processes audio signals to create a null and steer it off-axis, manipulating interaural level differences to generate virtual sound sources perceived as being offset from the center, using techniques like time delay and signal inversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If many speakers are used to create a wide soundstage, then the listening experience is improved, but the device complexity, weight, and cost increase
Solution Approach 1:
The patent creates virtual copies of sound sources through signal processing techniques (interaural crosstalk cancellation and null steering) that simulate the acoustic effect of multiple speakers positioned around the listener. Instead of physically placing many speakers, the system generates virtual sound images that the human brain perceives as coming from multiple locations, effectively copying the acoustic field of a multi-speaker system using only 2-3 physical speakers.
Solution Approach 2:
The patent replaces the mechanical approach of physically distributing multiple speakers throughout the vehicle with a signal processing approach. By manipulating audio signals through digital processing (creating nulls and steering them to specific locations), the system achieves spatial sound distribution without the mechanical complexity of multiple physical speaker units, thereby reducing weight, cost, and device complexity while maintaining the listening experience.
2Length of stationary object
If many speakers are used to create a wide soundstage, then the soundstage width is improved, but the weight and packaging space increase
Solution Approach 1:
The system creates virtual acoustic images of sound sources at various positions around the listener through signal processing, copying the perceptual effect of a wide soundstage without the physical weight of multiple speakers. The virtual sound sources are positioned to create a wide stereo image, achieving the same acoustic outcome as a distributed speaker array would provide, but with dramatically reduced weight using only 2-3 physical speakers.
3Reliability
If complex signal processing methods are used to achieve desired listening experience, then the soundstage quality is improved, but the processing power and cost increase
Solution Approach 1:
The patent extracts and isolates the essential processing functions needed to create a wide soundstage, focusing specifically on interaural crosstalk cancellation and null steering algorithms. By concentrating on these core processing tasks rather than implementing full multi-channel spatial audio processing, the system achieves effective soundstage generation with minimal processing power, removing unnecessary computational complexity while maintaining soundstage quality.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively generates a virtual soundstage with virtual sound sources positioned in front, left, and right of the listener, providing a wide soundstage experience with minimal equipment and processing power, suitable for automotive environments.
Implementation Method 1
A signal processing unit is configured to receive an incoming audio signal, to process left and right channel signals of the incoming audio signal to generate a null
Implementation Method 2
The null is steered by adding time delay to one speaker. As a result of the null hitting one ear of the listener, interaural level difference is manipulated, affecting localization
Implementation Method 3
The null is steered by adding time delay to one speaker
Implementation Method 4
the signal processing unit is configured to feed an inverted signal to one of the speakers in the compact speaker array to generate the null
Data Source
AI summary
A system and method for generating a virtual soundstage in a listening environment having a compact speaker array centrally positioned in a listening environment. A listener is sitting offset from the speaker array and the virtual soundstage is generated in front of a listener. A signal processing unit is configured to receive an incoming audio signal, to process left and right channel signals of the incoming audio signal to generate a null, and to steer the null toward one ear of a listener thereby generating a virtual sound source that is offset from the center of the listening environment. Virtual sound sources are generated in front of, to the left of, and to the right of the listener.