Multichannel Audio Bass Enhancement Using Limiter Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional audio processing systems face challenges in maintaining spectral balance and preventing distortion during loud playback, as they often undo previously applied effects and fail to consider previous processing in the signal chain, leading to cancellation of bass enhancement and potential reduction in overall playback volume.
Innovation Solution
A system that performs audio enhancement, specifically bass enhancement, in response to compression feedback from a multiband limiter, using a combination of psychoacoustic and equalization-type bass enhancement techniques to dynamically adjust frequency bands and prevent distortion, while maintaining spectral balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If equalization-type bass enhancement is applied to boost low frequency content, then bass response is improved, but speaker distortion occurs at high volume levels
Solution Approach 1:
The system employs feedback from the multiband limiter to dynamically control bass enhancement. The limiter monitors compression applied to frequency bands and feeds this information back to the bass enhancement processor, which adjusts its output accordingly. This feedback loop prevents bass enhancement from causing speaker distortion by reducing enhancement when the limiter is actively compressing low frequency bands.
Solution Approach 2:
The bass enhancement system transitions from static equalization to dynamic control based on real-time limiter feedback. The amount of bass enhancement varies dynamically according to the compression state of each frequency band, allowing maximum enhancement when speakers can handle it and minimal enhancement when approaching distortion thresholds.
2Object-affected harmful factors
If multiband compression is applied to reduce speaker distortion, then speaker distortion is prevented, but bass enhancement effects are counteracted and overall playback volume is reduced
Solution Approach 1:
The bass enhancement is applied before the multiband limiter in the signal chain. This preliminary action allows the bass enhancement to work on the full-range signal, and the limiter then controls the final output to prevent distortion. The limiter's feedback about its compression action allows the bass enhancement to compensate for any attenuation it causes.
Solution Approach 2:
The multiband limiter provides feedback about the compression applied to each frequency band back to the bass enhancement processor. This feedback enables the bass enhancement to dynamically adjust its output to maintain bass response while respecting the limiter's distortion prevention constraints.
3Object-affected harmful factors
If conventional limiting is applied to ensure speakers do not distort, then speaker distortion is prevented, but spectral imbalance occurs at higher volumes and previously applied effects are undone
Solution Approach 1:
The system uses feedback from the multiband limiter to maintain spectral balance. The limiter monitors compression in each frequency band and feeds this information back to the bass enhancement processor, which compensates for spectral changes by adjusting bass enhancement levels. This feedback loop preserves the spectral balance intended by the original audio mixing while preventing speaker distortion.
Solution Approach 2:
The system applies different processing strategies to different frequency bands based on local conditions. The multiband limiter operates independently on each frequency band, and the bass enhancement responds to band-specific compression feedback. This local quality approach allows spectral balance to be maintained in each band rather than applying uniform limiting across the entire spectrum.
Data Source
Figure 1~2
Figure 3~4
Figure 3A
AI summary
In some embodiments, a method for performing at least one of enhancement, decoding, or rendering of a multichannel audio signal in response to compression feedback or feedback from a smart amplifier. For example, the compression feedback may be indicative of amount of compression applied to each of multiple frequency bands, of the audio signal or an enhanced audio signal generated in response thereto. The enhancement (e.g., bass enhancement) may include dynamic routing of audio content of the input audio signal between channels of an enhanced audio signal generated in response thereto. The enhancement and compression may be performed on a per speaker class basis. Other aspects are systems (e.g., programmed processors) and devices (e.g., devices having physically-limited bass reproduction capabilities, such as, for example, a notebook or laptop computer, tablet, soundbar, mobile phone, or other device with small speakers) configured to perform any embodiment of the method.