title: Analysis and control of multi-zone sound field reproduction using modal-domain approach.
abstract: Multi-zone sound control aims to reproduce multiple sound fields independently and simultaneously over different spatial regions within the same space. This paper investigates the multi-zone sound control problem formulated in the modal domain using the Lagrange cost function and provides a modal-domain analysis of the problem. The Lagrange cost function is formulated to represent a quadratic objective of reproducing a desired sound field within the bright zone and with constraints on sound energy in the dark zone and global region. A fundamental problem in multi-zone reproduction is interzone sound interference, where based on the geometry of the sound zones and the desired sound field within the bright zone the achievable reproduction performance is limited. The modal-domain Lagrangian solution demonstrates the intrinsic ill-posedness of the problem, based on which a parameter, the coefficient of realisability, is developed to evaluate the reproduction limitation. The proposed reproduction method is based on controlling the interference between sound zones and sound leakage outside the sound zones, resulting in a suitable compromise between good bright zone performance and satisfactory dark zone performance. The performance of the proposed design is demonstrated through numerical simulations of two-zone reproduction in free-field and in reverberant environments.
authors.affiliation: Center of Intelligent Acoustics and Immersive Communications, Northwestern Polytechnical University, 127 Youyi West Road, Xi'an, Shaanxi 710072, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 0200, Australia.
authors.forename: Thushara D
authors.initials: TD
authors.lastname: Abhayapala
authors.affiliation: Digital Media and Communications R&D Centre, Samsung Electronics, Seoul 06765, South Korea.
authors.forename: Terence
authors.initials: T
authors.lastname: Betlehem
authors.affiliation: Institute of Sound and Vibration Research, University of Southampton, SO17 1BJ, United Kingdom.
authors.forename: Filippo Maria
authors.initials: FM
authors.lastname: Fazi