Patent Review: Inverse Horn Loudspeakers

This article reviews a patent originally granted to inventors Philip R. Clements; (Tempe, AZ), Boaz Shalev; (Needham, MA), and James Joseph Croft, III; (Bellevue, WA), which has now expired. The patent describes a low-frequency transducer system with a multi-compression chamber, where an inverse horn structure is employed in combination with a resonance-distortion filter chamber. This was the third patent granted on Atlantic Technology’s low frequency system known by the trademark name H-PAS (High Pressure Acceleration System). This article was originally published in Voice Coil, September 2016.

It's an historical moment for Resonado Labs, which announced a strategic partnership to develop a new line of Klipsch home audio solutions integrating its technologies. Together, the companies aim to develop a line of products engineered to deliver the highest output possible in sleek and compact form factors. A major accomplishment for the speaker technology startup, which has not stopped to surprise the market with its innovative transducers.

An overview of Loudsoft's latest FINE Suspension Nonlinear FEA Spider and Surround Design software. This new transducer engineering tool, specific to the development of speaker surrounds and spiders (dampers), allows for the simulation of different types of surrounds and spiders from imported DFX files or created from templates with parameters selected by the user, and then outputs the compliance curves similar to the Kms and Cms curves measured by Klippel DA2 or KA3 analyzers.

This Test Bench article characterizes Eighteen Sound’s AMT200P Air Motion Transformer and accompanying XMT200 6.5” waveguide. This driver is the brand's latest entry into the high-frequency transducer category, specifically designed for the pro sound community. The Eighteen Sound AMT200P includes a rectangular throat with a Kapton diaphragm with a neodymium magnet structure, and is rated for a power handling of 90W AES above 1.2kHz, with a sensitivity of 105dB, and a recommended crossover frequency of 1.2kHz at 48dB/octave. While the AMT200P can be used as a standard planar device it can be also coupled with a dedicated constant directivity horn, the 90°x 20° XMT200, featured in the characterization.

This Test Bench explication characterizes the 15DS100 15” professional subwoofer from B&C Speakers. This new transducer from the Italian company is a very high power handling design, able to deliver 3kW continuous (1.6W nominal), thanks to B&C's latest generation of very long voice coils - a great asset in applications from discreet PA subwoofers to three-way PA speakers. The B&C 15DS100-4 uses a proprietary 12-spoke cast aluminum frame with cooling vents for the neodymium FEA motor, which uses a 4” four-layer voice coil wound with round aluminum wire on a non-conducting glass fiber former. This article was originally published in Voice Coil, October 2021.

In the first part of this work, the authors discussed the difficulties in estimating cabinet losses using the classical Thiele-Small framework, and proposed a solution using an advanced transducer model. In this second article, the authors detail how their Speakerbench web-app offers an accurate and practical approach to this problem, and demonstrate how users will be able to easily and accurately determine the best suitable box volume for a loudspeaker system. This article was originally published in audioXpress, September 2021.

Sound Solutions International (SSI) introduced its latest family of high-performance microspeakers featuring improvements on loudness, linearity, and distortion levels by featuring the company's Coil-Anchor System (CAS) rocking suppression technology. The new microspeakers can easily scale for multiple applications and requirements in highly constrained mobile and portable designs. The patent-pending high-excursion Manticore speaker family already includes three models for smartphones and laptop/tablet applications.

CUI Devices’ Audio Group announced the introduction of a 3.2mm x 3.2mm magnetic transducer buzzer, making it among the smallest micro buzzers in the industry. As the latest addition to CUI Devices’ micro buzzers line, the CMT-322-65-SMT-TR features a low profile of 2mm, surface mount packaging, and a sound pressure level (SPL) of 65 dBA at 10 cm. The new product targets uses in portable equipment and space-constrained designs.

Resonado Labs is rapidly growing its US engineering team, and now announced the appointment of Benny Danovi as the new company Vice President of Engineering and Principal Transducer Engineer. In his new role leading the transducer team, Danovi will spearhead the expansion of the company’s proprietary Flat Core Speaker (FCS) technology architecture with a focus on next generation driver designs for automotive and multimedia applications.

This contributed article by Hermann Schenk, and Lutz Ehrig describes a new transducer technology that promises to be a power efficient solution for wireless earbuds. Arioso Systems is a successful Fraunhofer IPMS spin-off company that is now launching an innovative sound transducer principle for miniaturized headphones, in-ears and hearables. The article describes how this new technology, and specifically the company's new MEMS topology can contribute to the next-generation of true wireless earbuds.