Multichannel room response equalization with a broadened control region using a linearly constrained approach and...

Area of Science:

• Acoustics
• Signal Processing
• Audio Engineering

Background:

• Room acoustics present challenges for effective sound reproduction.
• Traditional equalization methods often have limited spatial coverage.
• Accurate sound field reproduction requires advanced signal processing techniques.

Purpose of the Study:

• To develop a room response equalization technique that widens the effective equalization area.
• To enable precise sound field matching at measured and interpolated control points.
• To reduce the number of required physical measurements for room equalization.

Main Methods:

• Utilizing an underdetermined multichannel inverse filtering (UMIF) and linearly constrained minimum variance (LCMV) approach.
• Formulating a constrained optimization problem to minimize matching errors.
• Employing plane wave decomposition-based sensor interpolation for unmeasured points.
• Applying a two-stage procedure with the least absolute shrinkage and selection operator (LASSO) for component selection.

Main Results:

• The proposed UMIF-LCMV system successfully widens the effective equalization area of the reproduced sound field.
• Precise matching at measured control points and minimized error at interpolated points were achieved.
• The system demonstrated efficacy with a linear loudspeaker and microphone array setup.

Conclusions:

• The developed technique effectively expands the listening area for room equalization.
• Limited discrete measurements are sufficient for achieving a wide effective equalization area.
• The combination of UMIF, LCMV, and interpolation offers a robust solution for acoustic equalization.