Patent Review: The Zoltan Bay Loudspeaker Patent

In this article, James Croft reviews a loudspeaker patent granted in 2015 to Zoltan Bay (Tiszaalpar, Hungary). The invention, which is the foundation for the BRS tweeter used in a remarkable series of Bayz Audio loudspeakers, basically describes a horizontally, omnidirectional transducer, using a multiple set of four to eight rolling, half-cylinder film diaphragms arranged in a circle to form a generally omni-directional radiator. This article was originally published in Voice Coil, September 2015.

In this article, James Croft dives in an interesting loudspeaker patent (US20150146910A1), awarded May 28, 2015 to multiple inventors from the Fraunhofer-Gesellschaft Institute in Munich, Germany. The patent describes a diaphragm drive system with a conventional electromagnetic motor and corrective piezoelectric elements that drive the suspension from a sensor that detects the nonlinearity and provides the corrective signal. This article was originally published in Voice Coil, September 2015.

This edition celebrates 35 years of Voice Coil, the Periodical for the Loudspeaker Industry. We discuss a new earphone technology for Balanced Frequency Range, Mike Klasco writes about Subwoofers and Bass, and James Croft reviews a new loudspeaker patent from Tymphany. Finally, Vance Dickason places Purifi Audio’s PTT4.0X04-NFA-01 Home Audio Midbass, and Eighteen Sound’s AMT200P AMT driver and XMT200 waveguide on the Test Bench. Now available in print or download.

The October 2021 edition of Voice Coil discusses "The State of Loudspeaker Magnetics," with an annual overview of these critical industry components and materials for loudspeakers, complemented with an updated industry directory focused on Integrated Electronics. James Croft covers a patent awarded to Coastal Source for the variable waveguide speaker control, while Vance Dickason characterizes the powerful 15DS100 professional subwoofer from B&C Speakers, and Eighteen Sound's latest ND2T 1.4” neodymium compression driver. Now available in print, immediate online access or download.

In this patents review, James Croft looks at one of the most interesting concepts for a “Desktop Audio Monitor System and Method.” US Patent 9036837, was granted in 2015 to James Tuomy (Framingham, MA), Barry Michael Kosherick (Hudson, MA), Laurie Wilk (Framingham, MA), and J. Richard Aylward (Ashland, MA). The concept was actually introduced to the market a year earlier, and made its big debut at the NAMM Show 2015, by Phasx Technologies. This article was originally published in Voice Coil, August 2015.

An interesting patent review of a Bipolar Speaker assigned to Definitive Technology, the Maryland-based company that is now part of Sound United. The patent describes a forward-focused bipolar loudspeaker design with front-facing and rear facing driver-arrays, adjusted to generate a front-to-back acoustical output balance equal to a 2:1 ratio (about 6dB reduction) in the output of the rear firing transducers relative to the direct forward output. This article was originally published in Voice Coil, June 2015

In this Voice Coil Acoustic Patents article, James Croft discusses an interesting Transmission Line Loudspeaker patent assigned to three engineers from Bose regarding an electro-acoustic driver and acoustic waveguide that includes “an enclosure, an acoustic transmission line formed within the enclosure, and a plurality of acoustic transducers contained within the enclosure and disposed along a length of the acoustic transmission line.” As Croft notes, this seems to be an improvement over the Tapped Horn loudspeaker architecture patented by Tom Danley, assigned 10 years ago. This article was originally published in Voice Coil, June 2015

Voice Coil July 2021 is now available and full of valuable articles. Starting with Mike Klasco's insights on glue joints and attachment techniques used in speaker design. Followed by an updated and comprehensive directory of manufacturers and suppliers of adhesives, coatings, and treatments for the speaker industry. James Croft reviews the recent Bidirectional Speaker patent awarded to Resonado Labs, and Vance Dickason places the totally unique Purifi PTT6.5X04-NFA-01 midbass driver on Test Bench, followed by Beyma's 12LEX1300Nd 12” woofer with its unique Maltcross cooling system. Now available in print and online!

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.

Following a recent exchange with loudspeaker designer and inventor John J. Gaudreault, we decided to revisit the very original Planar-Pivot (Planot) Transducer, and make available the two related articles that were published by Voice Coil in its May 2011 edition, and the respective Patent Review by James Croft published in the August edition of that same year. Hoping this will inspire some commercial implementations of this interesting concept, available for licensing.