Late-Reverberation Filter Setting for Room Standing-Wave Control
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Solution Overview
Problem
Existing methods for controlling standing waves in a room require a microphone to be placed at a listening position, limiting their effectiveness and flexibility.
Innovation Solution
A method and device that measure the impulse response of a room, extract the late reverberation component, and generate a filter coefficient to adjust frequency response based on this component, allowing control of standing waves regardless of microphone position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the entire frequency response is used to set dip filter coefficient, then not only standing waves but also other sound components can be adjusted, but the microphone must be placed at listening position
Solution Approach 1:
The patent extracts the late reverberation component from the impulse response, separating it from other sound components such as direct sound and early reflections. This extraction allows the system to focus specifically on standing wave control without requiring the microphone to be at the listening position, as the late reverberation component contains the standing wave information that is distributed throughout the room.
Solution Approach 2:
The patent segments the impulse response into different components (direct sound, early reflections, late reverberation) and processes only the late reverberation component for standing wave control. This segmentation enables independent optimization of standing wave correction without being constrained by the limitations of using the entire frequency response.
2Measurement precision
If microphone is placed at listening position for adjustment, then accurate frequency response measurement is achieved, but the method lacks flexibility for different microphone positions
Solution Approach 1:
By extracting the late reverberation component from the impulse response, the patent isolates the portion containing standing wave information that is less dependent on microphone position. This extraction enables accurate standing wave measurement even when the microphone is not placed at the listening position, thus providing both measurement precision and position flexibility.
3Adaptability or versatility
If late reverberation component is extracted and used for filter setting, then standing wave control is achieved regardless of microphone position, but processing complexity increases
Solution Approach 1:
The patent applies extraction to isolate the late reverberation component, which simplifies the overall processing by focusing only on the relevant portion of the impulse response that contains standing wave information. While extraction itself adds a processing step, it reduces the need for complex position-dependent adjustments and enables a more systematic approach to standing wave control.
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
Enables effective control of standing waves in a room, providing high-quality sound by reducing flutter echo and improving audio experience.
Implementation Method 1
measuring an impulse response of a room in which a speaker is placed
Implementation Method 2
extracting a late reverberation component of the measured impulse response
Data Source
AI summary
A filter setting method includes measuring an impulse response of a room in which a speaker is placed. The filter setting method also includes extracting a late reverberation component of the measured impulse response. The filter setting method also includes detecting a difference between a frequency-amplitude characteristic of the extracted late reverberation component and a predetermined target characteristic. The filter setting method also includes generating a filter coefficient that achieves a frequency response including amplification or attenuation according to the difference. The filter setting method also includes setting the filter coefficient in a filter configured to process an audio signal fed to the speaker.