All items in category Magazine Articles
R&D Stories: The Tetrahedral Test Chamber Story (Part 2) - Consistent Loudspeaker Measurements
by Geoff Hill

R&D Stories: The Tetrahedral Test Chamber Story (Part 2) - Consistent Loudspeaker Measurements

In this article Geoff Hill completes the Tetrahedral Test Chamber story, a concept born out of necessity, simple wavelength theory and Beranek's wedges, measurement theory, and building upon experience gained in designing chambers in Europe, US, and Asia. These chambers are now in use throughout the world, providing consistent, reliable, and accurate measurements of loudspeaker transducers and loudspeaker systems. This article was originally published in audioXpress, October 2021.
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R&D Stories: The Tetrahedral Test Chamber Story (Part 1) - Recognizing the Need for Consistent Measurements​
by Geoff Hill

R&D Stories: The Tetrahedral Test Chamber Story (Part 1) - Recognizing the Need for Consistent Measurements​

This article revisits the story of the development of the Tetrahedral Test Chamber (TTC), by Geoff Hill, loudspeaker engineer, author, and inventor, in an effort to solve the longstanding problem of making consistent loudspeaker measurements. This innovative loudspeaker test chamber is now defined in international standards and in use throughout the world, scalable to any size of loudspeaker driver. This article was originally published in audioXpress, September 2021.
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Patent Review: Acoustical Window Assembly for Vehicle and Home Theater Solution
by James Croft

Patent Review: Acoustical Window Assembly for Vehicle and Home Theater Solution

James Croft reviews two patents for a new type of subwoofer architecture. The first is intended for use in an automobile and the second, for use in a domestic listening room. The first patent relates to an “Acoustical Window Assembly for Vehicle,” while the second describes a home-theater solution using essentially the same concept, adapted to one or more home windows. Both patents were awarded to Magna International, Inc. This article was originally published in Voice Coil, October 2015.
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The Complete Linear Audio Library on USB
by Gary Galo

The Complete Linear Audio Library on USB

Linear Audio, the bookzine created in 2010 by Jan Didden, is now available on a USB with The Complete Linear Audio Library. We asked three Linear Audio and audioXpress authors - Gary Galo, Bob Cordell, and Dimitri Danyuk - to review it and share their thoughts. Important to know, the USB drive doesn't contain only the PDFs of published articles. It also ads additional articles by Jan Didden and others, together with materials of historical interest.
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The Lab Bench of 2021: Virtins Multi Instrument Measurement Software
by Stuart Yaniger

The Lab Bench of 2021: Virtins Multi Instrument Measurement Software

Stuart Yaniger shares his more recent experiences with Virtins Multi Instrument Measurement Software, which he combined with his RME ADI-2 Pro FS R audio interface and the Linear Audio Autoranger II to create what he defines as the Lab Bench of 2021. This is a very complete solution for anyone working on product testing and evaluation from home. It is also an approach that complements Yaniger's 2015 series of audioXpress articles on how to adapt home computers and sound cards for audio test and measurement. In this article, he experiments and updates his findings about Virtin's Multi Instrument software. This article was originally published in audioXpress, March 2021.
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OEM DSP Active Line Level Crossovers from Danville Signal
by Vance Dickason

OEM DSP Active Line Level Crossovers from Danville Signal

The advantages of active DSP crossovers are long recognized and a majority (about 90%) of today's professional audio loudspeakers and studio monitors are powered loudspeakers using also some kind of integrated DSP. Based in Minneapolis, MN, Danville Signal Processing has long been supplying high-performance DSP crossovers and DSP modules to the OEM market. In this article, Vance Dickason writes about the range of DSP Active Line Level Crossovers available from the company. This article was originally published in Voice Coil, September 2021.
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DaS AuReality — 3D Loudspeaker Technology
by Joe Hayes

DaS AuReality — 3D Loudspeaker Technology

A fully patented 3D loudspeaker technology resulted from a multi-year effort of Diffusion at Source (DaS) and elliptical soundfield speaker design approaches. DaS AuReality has evolved out of work known as “Acoustic3D” from an Australian-based company and is now being commercialized by Vastigo, Ltd. (Vastigo.com), headquartered in Singapore. This article offers all the details into the unique approach followed by the development and multiple applications segments envisioned by the inventors. This article was originally published in Voice Coil, September 2021.
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Patent Review: The Zoltan Bay Loudspeaker Patent
by James Croft

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.
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Patent Review: A New Electro Acoustic Drive System With Sensor from Fraunhofer
by James Croft

Patent Review: A New Electro Acoustic Drive System With Sensor from Fraunhofer

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.
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Fresh From the Bench: Parasound Halo JC 5 Stereo Power Amplifier - The Measurements
by Stuart Yaniger

Fresh From the Bench: Parasound Halo JC 5 Stereo Power Amplifier - The Measurements

Oliver A. Masciarotte was looking for an amplifier that he could respect without emptying his bank account. Richard Schram offered to send the Parasound JC 5, his company’s largest stereo power amplifier for evaluation. Anticipating the fun of enjoying the pleasures of this John Curl design, Oliver accepted the challenge, and Stuart Yaniger tested the JC 5 to confirm the amplifier’s merits with actual measurements. This article was originally published in audioXpress, September 2021.
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