Room-Adaptive Loudspeaker Audio Using Acoustic Sensing
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Solution Overview
Problem
Existing audio systems require multiple speakers to create a natural sound field, increasing cost and complexity, and are affected by nearby obstacles that alter sound reflections based on frequency.
Innovation Solution
An audio system with integrated sensing logic and low frequency correction filters adjusts audio output based on the acoustic environment, using fewer speakers to compensate for room effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple loudspeakers are used to create a natural sound field, then the sound reproduction quality is improved, but the cost and device complexity increase
Solution Approach 1:
The patent changes the electrical parameters of the loudspeaker signal by applying correction filters that modify the frequency response. The system applies different gain adjustments to different frequency bands to compensate for room acoustic effects, particularly enhancing low frequencies that are most affected by boundary reflections. This allows a single loudspeaker to produce a sound field that compensates for room effects without requiring multiple speakers.
2Manufacturing precision
If multiple loudspeakers are used to create a natural sound field, then the sound reproduction quality is improved, but the cost increases
Solution Approach 1:
The patent modifies the electrical characteristics of the audio signal through frequency-dependent correction filters. By adjusting the gain and phase parameters of the signal across different frequency bands, the system compensates for acoustic boundary effects using only one loudspeaker, thereby eliminating the need to purchase and install multiple expensive speakers while maintaining natural sound reproduction quality.
3Adaptability or versatility
If acoustic boundaries are present near the loudspeaker, then reflections are created that may enhance or degrade sound, but the sound quality becomes unpredictable and frequency-dependent
Solution Approach 1:
The system incorporates sensing logic that measures the acoustic environment and uses this information to adjust the audio signal in real-time. By monitoring the room's acoustic characteristics and feeding this information back to the correction filters, the system dynamically compensates for boundary reflections and other environmental factors, ensuring consistent sound quality regardless of the acoustic boundaries present.
Solution Approach 2:
The patent applies frequency-dependent gain adjustments through correction filters that modify the electrical signal parameters based on the detected acoustic environment. The system particularly targets low frequency ranges (below 400 Hz) that are most susceptible to boundary reflections, adjusting the signal parameters to compensate for these effects and maintain predictable, high-quality sound reproduction.
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
The system provides a natural sound reproduction with fewer speakers by dynamically adapting audio signals to the acoustic environment, enhancing sound quality and reducing complexity.
Implementation Method 1
Loudspeaker reproduction is affected by nearby obstacles, such as walls. Such acoustic boundaries create reflections of the sound emitted by a loudspeaker.
Implementation Method 2
The effect of the reflections may vary depending on the frequency of the sound. Lower frequencies, particularly those below about 400 Hz, may be particularly susceptible to the effects of reflections from acoustic boundaries.
Data Source
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AI summary
An audio system includes one or more loudspeaker cabinets, each having loudspeakers. Sensing logic determines an acoustic environment of the loudspeaker cabinets. The sensing logic may include an echo canceller. A low frequency filter corrects an audio program based on the acoustic environment of the loudspeaker cabinets. The system outputs an omnidirectional sound pattern, which may be low frequency sound, to determine the acoustic environment. The system may produce a directional pattern superimposed on an omnidirectional pattern, if the acoustic environment is in free space. The system may aim ambient content toward a wall and direct content away from the wall, if the acoustic environment is not in free space. The sensing logic automatically determines the acoustic environment upon initial power up and when position changes of loudspeaker cabinets are detected. Accelerometers may detect position changes of the loudspeaker cabinets.