The Effect of Enclosure Coupling on a Dual-layer Linear Loudspeaker Array

Loudspeaker arrays are increasingly being used in a variety of applications where there is a restriction on the electrical power consumption and the array must be robust to changes in the acoustic environment. Previous work has demonstrated that the efficiency and robustness of a two-source endfire loudspeaker array can be improved by acoustically coupling the two loudspeakers via a common enclosure. This paper presents an investigation into the effects of using acoustically coupled enclosures in a dual-layer linear loudspeaker array. Three different dual-layer array designs will be compared. In the first configuration each loudspeaker is mounted in its own enclosure and, therefore, there is no internal coupling between the loudspeakers. In the second configuration, each pair of front-to-back loudspeakers in the dual layer array are coupled via a common enclosure. Finally, in the third configuration all of the loudspeakers are coupled via a single enclosure. The performance of the three array configurations is investigated in terms of the acoustic contrast, the array effort, or electrical power, and the robustness to variations in the electroacoustic responses. Through this investigation it is shown that an increase in efficiency can be achieved by coupling the front-to-back pairs of loudspeakers in the dual-layer linear array.