A Lasso-LS Optimization with a Frequency Variable Dictionary in a Multizone Sound System.

This paper presents an approach for multizone wideband sound field generation using an efficient harmonic nested (EHN) dictionary for sparse loudspeakers' placement and weight. Effectively, the nested arrays provide a priori knowledge of prospective loudspeaker locations based on the frequency bands of interest. The nested arrays are then further optimized in the Lasso stage to form an efficient loudspeakers' location dictionary. The final loudspeaker locations and weightings are estimated by a two-stage Lasso-LS pressure matching optimization. In the first stage Lasso algorithm, the center band frequencies of octave bands from 1 kHz to 8 kHz were used to select active loudspeakers. A second stage then optimizes reproduction using all selected loudspeakers on the basis of a regularized LS algorithm. The results demonstrate that the proposed approach provides a solution for the multizone sound system with the mean squared error (MSE) under -30 dB across the targeted frequency range (500 Hz-16 kHz) using a linear array e.g. 13 loudspeakers. While, the single-stage LS approach generates the MSE peaks of -10 dB and -9 dB at 9 kHz within the active and silent zones respectively using an identical number of loudspeakers and array length.