How Good Is Your Port

Ported enclosures are known to extend the low-frequency output of loudspeakers by exploiting the Helmholtz resonator effect produced by the compliance of the air inside the enclosure and inertance of the air in the port. This article looks at the problem of port nonlinearity to determine the correct port size, and the acoustic impedance of the port under high air velocity. This article was originally published in audioXpress, September 2001.

COMSOL announced the latest version of COMSOL Multiphysics Version 5.4, which in addition to two new products provides performance improvements and additional modeling tools. The latest version of COMSOL Multiphysics features COMSOL Compiler, giving specialists the freedom to distribute their simulation applications through executable files, and the Composite Materials Module for layered structures analysis. For acoustics modeling applications, the update introduces acoustic ports and nonlinear acoustics Westervelt model.

When Sony introduced its new flagship Signature Series MDR-Z1R headphones, it received mixed reviews from precisely the user communities that it targeted, considering its hefty price tag that placed it in direct competition with Audeze, MRSpeakers, HiFiMan or Stax. Already announced in Asia and more recently at IFA in Europe, the new Sony MDR-Z7M2 premium headphones inherited core technology from the MDR-Z1R, uses new 70mm drivers, keeps the comfortable design, and retails at a much more affordable price.