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And expanding on the technologies that will undoubtedly contribute to making the next generation of hearables and advanced audio systems, audioXpress is privileged to publish another key article contributed by the experts in optical MEMS microphones from sensiBel. As the Norwegian company enters the market with its first-generation products, Jakob Vennerod and Michael Tuttle explain how 80dB SNR optical MEMS microphones will enhance Microphone Array Beamforming and the different types of beamforming algorithms. Essential reading to understand how new products and designs will benefit from this technology that will redefine expectations.
And expanding on our headphone and in-earphones focus to practical test and measurement, this issue also includes a valuable work by Brian Johansen, Per Rasmussen, and Morten Pedersen from GRAS Sound & Vibration, sharing their simulation work to assess the pressure field and its impact on different ear canal geometries. Frequency response is not the only important factor in testing in-ear headphones, and instead, the listening experience is largely influenced by how the pressure field is built up in the semi- or fully closed ear simulator, making leak and insertion position overshadowing parameters. Learn more about this research that revealed surprising conclusions, fundamental to ensure consistency and repeatability when characterizing in-ear devices.
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And because we are discussing hearing, we need to also highlight the second article on Hearing and Audio by Milind N. Kunchur, included in this issue. Explaining the latest finds regarding our hearing, the conversion of sound into neural signals and the processing of these signals, this two-part article series addresses the implications for our perspectives about reproducing music to the highest fidelity. This second article discusses resolution, detectability, and the consequences for blind testing. Truly fascinating.
Of course, it cannot all be about hearing and hearables. This April 2024 issue of audioXpress evolves with a variety of topics, including an appetizer for our forthcoming Glass Audio May issue. This month, Jan Didden shares a rewarding conversation with Menno van der Veen. Our readers will be familiar with his name, from the multiple DIY articles audioXpress has already published, and from his outstanding work on high-performance power and tube output transformers. He is also the founder of the TubeSociety, a remarkable organization where he teaches the design, construction, and testing of high-end tube amplifiers.
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This issue includes an amazing project that was brought to us by Andrew C. Russell of Hifisonix fame. From his experienced hands comes the ax-Amplifier, a Class A design that uses Augmented Feedback Error Correction (AFEC) to achieve ultra-low distortion and improve key audio performance parameters without adding too much complexity and cost. Published in two parts, the first article addresses the amplifier design in detail, with Part 2 (audioXpress May) detailing the power supply system and conclusion with measurements.
Next up, Tom Perazella also brings us an enjoyable - and very useful - practical construction: A Comprehensive AC Power Controller. Many people take their AC mains power for granted, but as Perazella has learned over the years and in different homes, to obtain maximum performance from our AC powered equipment and extend service life, several potential problems of typical mains power must be addressed. This article describes a practical AC mains power controller with a complete set of features to address any worries in that department.
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All the content contained in every issue of audioXpress is the reason why, month after month, 12 times per year, this publication continues to reinforce its role as an essential resource for the audio industry. Your support and that of our advertisers is what allows us to keep this publication in print and all digital platforms and pay our independent authors and contributors for their work.
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