Speaker
Description
The interaction between the enclosure and the acoustic back radiation generated by a loudspeaker driverplays a crucial role in shaping the overall emission characteristics of the loudspeaker system. In this study,Subwavelength Corrugated Surfaces (SCSs), a classof acoustic metasurfaces, are proposed to passivelycontrol the internal propagation of acoustic back radiation and its angular redistribution. The proposedapproach enables the refocusing of the back radiationin lateral directions, while preserving an on-axis soundpressure level comparable to that of a conventionalclosed-box loudspeaker within the frequency rangewhere the metasurface is effective. The behavior ofthe system is assessed through a numerical investigation based on finite-element modeling in COMSOLMultiphysics. Three configurations are analyzed: aconventional closed-box system, a loudspeaker systemwith an open side wall, and a system with open sidewall incorporating the SCS. The simulations allowa direct comparison between the different solutionsand highlight the potential of SCSs to shape loudspeaker acoustic back radiation and extend directivitycontrol through compact, purely passive structuralmodifications.