Patent Review: Loudspeaker Apparatus

This article reviews a patent awarded to Teppei Yamada, on behalf of Zorzo Co., Ltd. (Tokyo, Japan), describing an original design of a low-frequency enclosure system incorporating multiple woofers inter-coupled in a manner similar to what is known as an isobaric or compound woofer enclosure. James Croft reviews other approaches to the concept, starting in 1954 with a patent granted to Harry F. Olson on a dual, compound woofer system and later "reinvented" and popularized by Linn Corp., in 1975. In the new patent, the inventor uses an enclosure with as many as 12 woofers, all seriously coupled through individual air chambers

A long term effort by José Brusi, the principal of Brusi Acoustics consulting firm and an independent laboratory for loudspeaker testing based in Valencia, Spain, PAcalculate is a very useful mobile app for audio professionals working in sound reinforcement. The latest PAcalculate v1.3.2 release was recently described by Brusi as "the most exciting update to date for the calculator app that tens of thousands of proaudio professionals keep installed in their mobile phones."

For several years, Mike Klasco and Steve Tatarunis wrote a series of articles under the header Parts is Parts where they have explored loudspeaker drivers, how they work, and all the different parts and components. In this specific article, the two audio industry experts provide an excellent introduction to high frequency drivers, revisiting some key historical designs. This article was originally published in audioXpress, January 2013.