Loudspeaker Group Delay Matching Under Filter Latency Limits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for controlling loudspeaker group delay are limited to adjusting the sound of a single loudspeaker and cannot effectively match the group delay between multiple loudspeakers.
Innovation Solution
A method and system for controlling loudspeaker group delay that involves acquiring latency values and group delays for each frequency of multiple loudspeakers, calculating adjustment amounts for audio signals, and generating frequency responses for filters to minimize delay differences between loudspeakers, using processors and memory units to execute these processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a filter is used to flatten the group delay of a single loudspeaker, then the group delay of that loudspeaker is improved, but the method cannot be used to match the group delay between multiple loudspeakers
Solution Approach 1:
The patent extends the filter-based group delay control method from single-loudspeaker applications to multi-loudspeaker systems. By calculating adjustment amounts based on group delay differences between multiple loudspeakers and generating corresponding frequency responses for each loudspeaker's filter, the system achieves universal applicability across multiple devices while maintaining group delay flatness for each individual loudspeaker.
2Manufacturing precision
If the frequency response of a filter is adjusted to control loudspeaker characteristics, then the group delay is flattened, but the latency of the filter increases
Solution Approach 1:
The patent optimizes filter design by carefully selecting and adjusting filter parameters such as cutoff frequencies and slopes to achieve group delay matching while minimizing latency. The system calculates adjustment amounts and generates frequency responses that balance the trade-off between group delay flatness and latency, allowing for controlled compromise based on application requirements.
Solution Approach 2:
The patent applies group delay control selectively in target frequency bands where it is most needed, rather than attempting to flatten group delay across the entire frequency spectrum. This partial action approach reduces the overall latency introduced by filters while still achieving effective group delay matching in the critical frequency ranges for audio reproduction.
Data Source
AI summary
A method includes acquiring a latency value defining delay of sound through a filter, acquiring a first group delay indicating delay for each frequency of sound of a first loudspeaker, acquiring a second group delay indicating delay for each frequency of sound of a second loudspeaker, calculating an adjustment amount for adjusting a first audio signal supplied to the first loudspeaker and/or a second audio signal supplied to the second loudspeaker, such that a difference in the sounds of the first and second loudspeakers in a target band is reduced, and generating, in accordance with the adjustment amount, a frequency response of a first filter that controls characteristics of the first audio signal and/or a frequency response of a second filter that controls characteristics of the second audio signal, while controlling a latency of the first filter and/or the second filter in accordance with the latency value.