title: Optimal source placement for sound zone reproduction with first order reflections.
abstract: The problem of delivering personal audio content to listeners sharing the same acoustic space has recently attracted attention. It has been shown that a perceptually acceptable level of acoustic separation between the listening zones is difficult to achieve with active control in non-anechoic conditions. A common problem of strong first order reflections has not been examined in detail for systems with practical constraints. Acoustic contrast maximization combined with optimization of source positions is identified as a potentially effective control strategy when strong individual reflections occur. An analytic study is carried out to describe the relationship between the performance of a 2 × 2 (two sources and two control sensors) system and its geometry in a single-reflection scenario. The expression for acoustic contrast is used to formulate guidelines for optimizing source positions, based on three distinct techniques: Null-Split, Far-Align, and Near-Align. The applicability of the techniques to larger systems with up to two reflections is demonstrated using numerical optimization. Simulation results show that optimized systems produce higher acoustic contrast than non-optimized source arrangements and an alternative method for reducing the impact of reflections (sound power minimization).
authors.affiliation: Centre for Vision, Speech and Signal Processing, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
authors.forename: Marek
authors.initials: M
authors.lastname: Olik
authors.affiliation: Centre for Vision, Speech and Signal Processing, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
authors.forename: Philip J B
authors.initials: PJ
authors.lastname: Jackson
authors.affiliation: Centre for Vision, Speech and Signal Processing, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
authors.forename: Philip
authors.initials: P
authors.lastname: Coleman
authors.affiliation: Bang & Olufsen A/S, Peter Bangs Vej 15, DK7600, Struer, Denmark.
authors.forename: Jan Abildgaard
authors.initials: JA
authors.lastname: Pedersen