All items tagged with James Croft (73)
Make It Active! Voice Coil October 2024 Is Now Available
October 1, 2024 by audioXpress Staff

Make It Active! Voice Coil October 2024 Is Now Available

In Voice Coil October 2024, Claus Futtrup writes about Compliance Alteration, and Mike Klasco and Nora Wong prepared an updated directory of Integrated Electronics for Loudspeakers. James Croft returns with a "Loudspeaker" patent review, granted to industry veteran Michael Levy, and Vance Dickason focuses solely on the eagerly awaited Purifi Audio PTT10.0X04-NAB-01 10" Midbass Woofer.
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Patent Review: Head-Related Transfer Function Equalization and Transducer Aiming of Stereo Dimensional Array (SDA) Loudspeakers
June 26, 2024 by James Croft

Patent Review: Head-Related Transfer Function Equalization and Transducer Aiming of Stereo Dimensional Array (SDA) Loudspeakers

This patent, awarded to Polk Audio, describes a very specific loudspeaker design that claims to be able to achieve better stereo sound reproduction with “a realistic ambient field and a larger, and more stable acoustic image.” This obviously aims at achieving something that Polk Audio actually patented nearly 40 years ago, with its original Stereo Dimensional Array (SDA) loudspeaker, and for which the new updated patent now provides a new improved version. This article was originally published in Voice Coil, February 2019.
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Patent Review: Multi-Layer Voice Coil Plate and Flat-Type Speaker Comprising the Same
June 19, 2024 by James Croft

Patent Review: Multi-Layer Voice Coil Plate and Flat-Type Speaker Comprising the Same

In this patent review, James Croft (Croft Acoustical) looks closely at a new patent of a multilayer voice coil plate and a flat speaker including the same type of multilayer voice coil plate, granted to three inventors from South Korea, on behalf of ICUBES Co., Ltd., Gyeongi-do, Korea. Detailing multiple configurations of this interesting concept, this patent offers an interesting take on the quest for the realization of a high-performance, one way, full-range electrodynamic transducer.
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Patent Review: Acoustic Passive Radiator Rocking Mode Reducing
June 12, 2024 by James Croft

Patent Review: Acoustic Passive Radiator Rocking Mode Reducing

With the increasing popularity of miniaturized systems, the application of the passive diaphragm radiator, as the acoustic mass component in a bass reflex enclosure, is becoming standard practice in the low-frequency portion of the system. And these systems have a few parameter demands that can exceed the capability of many conventional approaches to passive radiator design. In order to solve those challenges, including rocking modes, Bose proposed an effective design.
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Patent Review: Acoustic Filter for Omnidirectional Loudspeaker
June 5, 2024 by James Croft

Patent Review: Acoustic Filter for Omnidirectional Loudspeaker

This is an interesting patent awarded to Lakshmikanth Tipparaju, Allan Devantier, William Decanio, and Andri Bezzola, on behalf of Samsung Electronics - effectively the audio research team that Samsung created in Valencia, CA. The industry has attempted to achieve a successful implementation of acoustic radiation closely coupled to a boundary surface for omnidirectional and subwoofer applications - unfortunately, mostly plagued by resonances generated by the waveguide or reflector surface. This new approach appears to be an effective solution.
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Voice Coil June 2024 Explores More Drivers and Transducer Options
May 29, 2024 by audioXpress Staff

Voice Coil June 2024 Explores More Drivers and Transducer Options

In the June 2024 issue of Voice Coil, Claus Futtrup explores the Linkwitz-Riley (LR4) Bass Reflex Alignment, in Acoustic Patents, James Croft revisits an important invention from Bang & Olufsen, which has been granted the respective patent, and Vance Dickason characterizes the new Wavecor WF211PA01 8.25" woofer and the Faital Pro 10PR330 10" woofer, both suitable for PA systems and professional applications. Finally, there's an updated industry directory of Headphone Test & Measurement Equipment.
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Voice Coil Patent Review: Controlled Passive Radiator
March 27, 2024 by James Croft

Voice Coil Patent Review: Controlled Passive Radiator

James Croft has fun reviewing a Controlled Passive Radiator patent awarded to inventor Tony Doy, on behalf of Sonos (Santa Barbara, CA.) The patent details multiple techniques to control a passive radiator, including a device buffering successive samples of audio content and predictive techniques on active designs. With this extensive review, Voice Coil readers will gain a valuable perspective on key possible innovation areas. This article was originally published in Voice Coil, October 2018.
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Ideas for Speaker Enclosures Now in Voice Coil March 2024
February 28, 2024 by audioXpress Staff

Ideas for Speaker Enclosures Now in Voice Coil March 2024

Voice Coil March 2024 focuses on speaker enclosures with a unique directory of innovative material ideas, followed by an always insightful patent review, where James Croft revisits the pivotal Dinaburg invention. For Test Bench, this month Vance Dickason characterizes the SIG180-4 6.5” woofer from Dayton Audio’s Signature Series, and a midbass shallow-profile 6.5” driver, the Stereo Integrity TM65 mkIV.
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Patent Review: Air Motion Transformer Passive Radiator for Loudspeaker
January 10, 2024 by James Croft

Patent Review: Air Motion Transformer Passive Radiator for Loudspeaker

In the August 2018 issue of Voice Coil, James Croft combined the review of two important independent patents, having in common the fact that they try to address the shortcomings of the work of Dr. Oskar Heil with his Air Motion Transformer (AMT) woofer system. Following a review of a Tymphany patent, Croft reviewed a related patent for an Air Motion Transformer Passive Radiator, invented by and awarded to Eugene Julius Christensen (Aspen, CO).
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Patent Review: Self-Bias Emitter Circuit
November 1, 2023 by James Croft

Patent Review: Self-Bias Emitter Circuit

This article reviews an intriguing new patent awarded to Turtle Beach Corp. addressing a new emitter circuit for providing a bias voltage, which is key for the development of electrostatic loudspeakers. Extremely aware of the techniques and historical perspective of the development in this area, Croft provides a complete overview of all the challenges, implications and merits of this patent and prior art. This article was originally published in Voice Coil, July 2018.
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