MTM Speaker Audio Filtering for Horizontal Interference Compensation
Solution Overview
Problem
Audio filter systems for mid-tweeter-mid (MTM) speaker configurations face challenges in maintaining consistent audio quality across different orientations, leading to a 'narrowing' phenomenon where audio frequencies are canceled out in certain positions, especially when speakers are oriented horizontally.
Innovation Solution
Implementing a digital audio processor that applies distinct filtering to audio signals for each mid-range speaker based on their orientation and configuration within a multiple-device arrangement, using filters such as low-frequency shelf, bandpass shelf, low-pass, allpass, and high-frequency shelf filters to compensate for interference and maintain consistent frequency response across various angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If speakers are oriented horizontally in MTM configuration, then installation flexibility is improved, but audio frequency cancellation occurs in certain positions due to interference
Solution Approach 1:
The patent applies different audio filters to different mid-range speakers based on their specific positions and orientations within the MTM configuration. Each speaker receives customized filtering treatment rather than uniform processing, allowing the system to maintain consistent audio output characteristics across various installation orientations while compensating for position-specific interference patterns.
2Device complexity
If uniform filtering is applied to all mid-range speakers, then device complexity is reduced, but audio consistency across different angles deteriorates
Solution Approach 1:
The patent implements dynamic filtering where the audio processing characteristics change based on the detected orientation and configuration of the speakers. The system automatically adjusts filter parameters and types according to the specific MTM arrangement, enabling consistent audio performance across horizontal, vertical, and other orientations without requiring manual reconfiguration.
3Reliability
If position-specific filtering is applied to compensate for interference, then audio consistency is improved, but device complexity increases
Solution Approach 1:
The patent pre-configures multiple filter types and characteristics that can be automatically selected based on the detected speaker orientation and position. Rather than calculating optimal filters in real-time, the system has predetermined filter profiles ready for different MTM configurations, reducing computational complexity while maintaining the ability to provide position-specific compensation for interference patterns.
Data Source
AI summary
A playback device identifies a first audio filter and a second audio filter. The first audio filter is configured to have a first frequency response and the second audio filter is configured to have a second frequency response. The audio input is processed according to the first audio filter and the second audio filter to produce respective first audio output and second audio output. The first audio speaker renders the first audio output and the second audio speaker renders the second audio output, where the second frequency response of the second audio filter compensates for interference between the first audio output rendered by the first audio speaker and the second audio output rendered by the second audio speaker.