Patent Review: Multiple Path Acoustic Wall Coupling for Surface-Mounted Speakers

This article reviews a patent awarded to Paul Wayne Peace Jr. and Derrick Rodgers, on behalf of Harman International Industries. The patent describes a surface-mounted loudspeaker design that mitigates the interference between direct low-frequency (LF) energy and reflected LF energy by breaking the LF energy from an LF driver into multiple paths using one or more of waveguides, driver load plates, and enclosure ports to diffuse the reflected energy and minimize frequency response errors.

As anticipated, COMSOL unveiled its Multiphysics Version 5.6 Software Suite introducing faster and more memory lean solvers, efficient CAD assembly handling, clip planes, layout templates for building apps, and four new products: Fuel Cell & Electrolyzer Module, LiveLink for Simulink, Polymer Flow Module, and Liquid & Gas Properties Module. Important news in the Acoustics Module include a new time explicit Nonlinear Acoustics interface that uses the dG-FEM technology, a new feature to model Nonlinear Thermoviscous Acoustics, mechanical Port boundary conditions for elastic waves, and much more.

A sound source, such as a loudspeaker, will experience an increase in directivity with increasing frequency, as the wavelength of sound becomes small compared to the baffle’s size. Since the baffle the driver is mounted on is larger than the driver, this occurs at a lower frequency than for the driver diaphragm itself. This article was published originally in Voice Coil, July 2016