All items in category Magazine Articles
Fresh From the Bench: Listen SoundCheck and AmpConnect 621 Audio and Acoustics Test Suite
by Rens Tellers

Fresh From the Bench: Listen SoundCheck and AmpConnect 621 Audio and Acoustics Test Suite

The latest version of Listen's flagship audio test software, SoundCheck 21, allowed audioXpress to review also the latest Listen AmpConnect 621 USB-controlled multichannel audio test interface. The innovative algorithms and increased measurement capabilities of this powerful and flexible software, together with the AmpConnect 621 analyzer, combines all the functionality required for audio testing in the lab bench or in the production line. This article was originally published in audioXpress, March 2024.
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Simulation Techniques: Acoustical Shape Optimization for Vibroacoustics Applications
by René Christensen

Simulation Techniques: Acoustical Shape Optimization for Vibroacoustics Applications

Having detailed how formal optimization can be used for product design of audio products such as speakerphones and waveguides, in this article René Christensen explores free-form and alternative optimization techniques where the topology of the geometry is given from the outset. Using practical examples, this article addresses shape optimization techniques, identifying useful types of boundaries and challenges to look out for audio product designs. This article was originally published in audioXpress, February 2024.
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A Visit to Audio Precision to See the New APx516 Analyzer
by Vance Dickason

A Visit to Audio Precision to See the New APx516 Analyzer

Vance Dickason visited Audio Precision's headquarters in Beaverton, OR, where he met with Dan Knighten, AP's Product Line General Manager, to talk about the new Audio Precision APx516 Analyzer. This is a new relatively economical analyzer for the company, with a base price of $6000, which means that the APx516 is ideal for use with remote engineering staff, making it practical for companies to have high-precision test and measurement work being done in multiple locations.
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Simulation Techniques: Room Gain
by René Christensen

Simulation Techniques: Room Gain

Room Gain is a term not used in acoustics textbooks as such. Room acoustics is naturally often discussed in the hifi community, since the room you put your loudspeakers in will heavily influence the sound that reaches your ears, both at low and high frequencies. In these discussions the term "room gain" sometimes comes up. This article was inspired by Erik Wiederholtz (CTO of Perlisten Audio) and his interest in the topic, and he was kind enough to provide measurements and photos from his own listening room for a sealed subwoofer as well as for a vented subwoofer.
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Simulation Techniques: Acoustic Topology Optimization for Vibroacoustics Applications
by René Christensen

Simulation Techniques: Acoustic Topology Optimization for Vibroacoustics Applications

Acoustic topology optimization is one of the most interesting new technologies in vibroacoustics. These powerful tools enable engineers to find optimal solutions to problems related to their specific applications and this article presents multiple examples in different areas. The article, originally published in audioXpress, April 2023, includes several examples of transducer geometries modified via acoustic topology optimization.
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A Look Inside Douglas Self’s "Small Signal Audio Design" 4th edition
by Jan Didden

A Look Inside Douglas Self’s "Small Signal Audio Design" 4th edition

Whether it is power amplifiers, vinyl reproduction preamplifiers, active crossover filters or, as in this case, small-signal circuits for a very wide range of applications, Douglas Self is one of those authors who consistently has produced reference works about technical audio. You may think that as a fourth edition, it would just be a refinement on the three editions that went before it but Self always adds new material and new insights to make it worthwhile to get this new book.
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Low Frequency in Loudspeakers: It’s All About the Bass!
by Mike Klasco

Low Frequency in Loudspeakers: It’s All About the Bass!

All the speaker design techniques to achieve more bass, challenging Hofmann's Iron Law. The same bass in a smaller enclosure? Deeper or louder bass for the same enclosure back volume? Higher efficiency for a given alignment? A cleaner lower distortion bass? Learn about the companies, products, and technologies that make all this possible. This article was originally published in Voice Coil, November 2023.
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Simulation Techniques: Lumped Element Modeling of Transducers
by René Christensen

Simulation Techniques: Lumped Element Modeling of Transducers

An exploration of the possibilities for product development focusing on modeling of transducers. As many engineering tasks require a common ground from which discussions among those involved in a project can take place in a structured manner, this often involves a so-called model of the concept or product. This article discusses one such model: the lumped element model. This article was originally published in audioXpress, March 2023.
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Voice Coil Patent Review: Controlled Passive Radiator
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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Bass Reflex Performance Envelope - Part 3: A Practical Example
by Gary Gesellchen

Bass Reflex Performance Envelope - Part 3: A Practical Example

In this article, Gary Gesellchen (Vanatoo) completes his Bass Reflex Performance Envelope exploration. After concluding the main analysis portion of the article determining his novel approach to estimating the performance envelope available from bass reflex loudspeakers, Part 3 shows an example to see how his calculations all work together, and addresses some practical considerations. This article was originally published in audioXpress, September 2023.
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