Patent Review: A Circular Shaped Planar Speaker System

The patent in review was granted in February 2015 to inventor Zhijun Zhao (West Bloomfield, MI) on behalf of Harman International Industries. As James Croft notes, planar magnetic transducers are often preferred for their thin form factor, ideal for shallow mounting spaces where a standard transducer may not fit, such as in-wall systems and automotive applications. The patent in review offers a practical solution for an oval or circular format planar magnetic transducer for such applications. This article was original published in Voice Coil, April 2015.

The April 2021 edition of Voice Coil is now available and combines a wide range of topics for loudspeaker industry professionals. Starting with "Practical Considerations for Quality Control Testing of Loudspeakers," to an overview of innovations in wires and connectors, and a directory of cable and connector vendors. And, Vance Dickason looks at two compression drivers matched with factory-supplied horns - the ND1TP from Eighteen Sound and the CD-11Nd from Acustica Beyma. Now available in print and digital.

James Croft looks at an interesting new patent covering a “Compact Stand-Alone Stereo Loudspeaker” by inventor Jes Mosgaard from Libratone A/S (Denmark). This patent submitted in 2010, was granted in 2013, and describes a compact and portable stereo loudspeaker system that is capable of providing a spacious sound field using an internal stereo pair of loudspeakers arranged in a dipole configuration. This article was originally published in Voice Coil, February 2015.