All items in category Magazine Articles
Patent Review: Bass-Reflex Speaker Cabinet Having a Recessed Port
by James Croft

Patent Review: Bass-Reflex Speaker Cabinet Having a Recessed Port

This patent awarded to inventor Matthias Larrieu, on behalf of French company NEXO (owned by Yamaha Corp.) was the topic of this detailed review by James Croft. From the abstract it might be difficult to visualize what exactly differentiates the patented design from a standard bass reflex system. Basically, Larrieu created two V-shaped slices at the opening either centered or with one at each side of the port, helping to reduce amplitude and phase anomalies in the midrange due to port resonances, while improving mid-band directivity.
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Remote Recording in the Rock Era: David Hewitt’s On the Road
by Scott Dorsey

Remote Recording in the Rock Era: David Hewitt’s On the Road

For an enjoyable suggestion, after you finish reading audioXpress, Scott Dorsey reviewed an interesting book written by David Hewitt, one of the many well-known engineers who made history doing live recordings of rock concerts during the 1970s and 1980s - and continued to pioneer this approach to make great recordings of live events. On the Road: Recording the Stars in a Golden Era of Live Music, is an interesting first person testimony of some of the greatest moments in music recording history. This article was originally published in audioXpress, April 2023.
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Practical Test & Measurement: REST for Automated Test and Measurement
by Matt Taylor

Practical Test & Measurement: REST for Automated Test and Measurement

This article is a great introduction to the use of web interfaces, and embracing web standards for automated testing of audio equipment, fundamentally exploring the possibilities of REST - which stands for Representational State Transfer, a widely accepted set of guidelines for creating reliable web APIs. Written by the founder of Seattle, WA-based QuantAsylum, this contributed piece advocates an open-design philosophy for controlling and querying things via REST, and leveraging the know-how of millions of developers. This article was originally published in audioXpress, March 2022.
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Patent Review: Rotary Transducer with Improved High-Frequency Output
by James Croft

Patent Review: Rotary Transducer with Improved High-Frequency Output

This article examines an important patent filed in 2014 by F. Bruce Thigpen (Tallahassee, FL) and granted in June 2016. Appearing both as the inventor and assignee, Thigpen describes a rotary sound transducer having an improved output at higher frequencies. Thigpen has been working on this type of device for more than a decade and has advanced what was already a very difficult engineering achievement, to a more sophisticated structure that apparently raises the general performance and high frequency limits beyond what was thought possible with this architecture. This article was originally published in Voice Coil, July 2017.
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Practical Test & Measurement: Transitioning Audio Tests from R&D to the Production Line
by Steve Temme

Practical Test & Measurement: Transitioning Audio Tests from R&D to the Production Line

Production line audio testing poses many challenges such as noisy environments, harsh operating conditions, high throughput, relative limits, and more. In this article, Steve Temme, the founder and President of Listen, writes about the essentials of test and measurement applied to manufacturing environments and quality control. Production tests always benefits from proven practices and experience and that's what is shared in this article, outlining the main considerations to ensure a successful operation. This article was originally published in audioXpress, March 2023.
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Practical Test & Measurement: The Proof Is in the Testing
by Adran Lara Moreno and Christian Bellmann

Practical Test & Measurement: The Proof Is in the Testing

The Klippel Near Field Scanner System (NFS) was used for the critical testing and measurement of Holoplot's X1 Matrix Array compensation algorithm capabilities. All our readers who have appreciated the story of the development of the unique Holoplot technology, published in the September 2022 issue of audioXpress, will enjoy reading about how Klippel and Holoplot worked to overcome frequency absorption and gain reduction challenges that resulted from the need to conceal the X1 systems behind an acoustically semi-transparent projection panel.
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Fresh From the Bench: Echo AIO - A Cost-Effective Audio Test System
by Stuart Yaniger

Fresh From the Bench: Echo AIO - A Cost-Effective Audio Test System

Headquartered in Santa Barbara, CA, Echo Test + Measurement is a little company with a big impact on audio test and measurement. As many large consumer electronics companies started using its AudioFire studio sound cards for production line testing, Echo designed a highly cost-effective, modular range of USB-based audio test interface solutions, which Stuart Yaniger had the opportunity to evaluate. He completed a series of tests and shares his experiences with the new Echo AIO modular audio test system.
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Modern PCB Design Practices: Part 2 — Tips and Techniques
by Ethan Winer

Modern PCB Design Practices: Part 2 — Tips and Techniques

The first article from audio expert Ethan Winer about Modern PCB Design Practices, gave a general overview of board design using surface-mounted devices (SMDs). The article examines current practices and methods for designing four-layer printed circuit boards using surface mounted components (SMDs), and this second part explains specific strategies and related issues to deal with the design and production of great quality PCBs. This article was originally published in audioXpress, March 2023.
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Patent Review: Passive Radiator with Dynamically Adjustable Resonant Frequency
by James Croft

Patent Review: Passive Radiator with Dynamically Adjustable Resonant Frequency

This review addresses an important patent awarded to Joseph F. Pinkerton (Austin, TX), on behalf of Clean Energy Labs, LLC. The patent describes an audio speaker having one or more passive radiators, and more specifically, an audio speaker having a passive radiator with dynamically adjustable resonant frequency. Croft reviews the patent and compares it with previous attempts to achieve this useful development, with significant potential if its full capability is realized.
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Modern PCB Design Practices: Part 1 — An Overview of the Process
by Ethan Winer

Modern PCB Design Practices: Part 1 — An Overview of the Process

In this two-part series, Ethan Winer examines current practices and methods for designing four-layer printed circuit boards using surface-mounted components (SMDs). A great article for our DIY readers and many developers who often are faced with the need to build and test their projects on a properly designed, prototype printed circuit board. Part 1 presents an overview of the process, while Part 2 he will explain specific strategies. Many related issues will be described along the way.
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