Leading-Edge Knowledge Available with Voice Coil December 2020

In Industry News & Developments, Vance Dickason takes us on a walk-through of the new Audio Precision APx517B Analyzer. This recently announced acoustic analyzer was specifically designed, configured, and built for the production-line testing of speakers, microphones, headphones, headsets, and a wide range of consumer electronics incorporating speakers and microphones. With the introduction of the APx517B, manufacturers can deploy an integrated acoustic test system that brings the renowned quality, reliability, and robustness of Audio Precision’s lab-oriented analyzers to the production lines. 

And to open up some exclusive features in this last 2020 edition, Chris Struck (CJS Labs) offers a quick primer on "Phase, Group Delay, and Impulse Response." This article is an expanded version of a previous Lab Note published by CJS Labs, and is certainly a great summary of essential knowledge in speaker design.

Next up, Mike Klasco (Menlo Scientific) writes about MEMS Drivers and related hot technologies for 2021, providing a timely update about products and companies that stood out in 2020. For this article, Klasco expands on the impact of microelectromechanical systems (MEMS) for audio and discusses the implications for other game-changing technologies that reduce size, increase performance, extend battery life, and enhance features and functionality in headphones, wearables and compact speakers.

This Focus topic is complemented with a Directory of MEMS manufacturers and Other Leading-Edge Devices for Wearables, compiled by Nora Wong (Menlo Scientific). The directory details profiles for companies as diverse as Ambiq Micro, Arioso Systems, Audio Pixels, Axign, Nanusens, GraphAudio, OR Graphene Audio, Sonion, Syntiant, TDK, USound, and xMEMS Labs.

In his Acoustic Patents column, James Croft (Croft Acoustical) discusses a patent granted in October 2020 to inventor Eric Jay Alexander (Orem, UT), for its MTM Loudspeaker Using Tweeter Arrays. The patent abstract details an MTM loudspeaker in which an array of smaller drivers replaces each of the larger drivers in a traditional MTM design as originally described by Joseph D’Appolito, in order to reduce the total moving mass of the drivers reproducing the lower-frequency sounds in the MTM design, in order to eliminate lobbing errors in the midrange. James Croft reviews the concept and cross-references with other existing patents from the same inventor, including a patent recently reviewed in the June 2020 edition of Voice Coil, also focusing on the merits of using multiple low-mass drivers.

For this edition's Test Bench, Vance Dickason characterizes the very recent BWX-6501 Midbass driver and the BDT-2901 High-End Silk Dome Tweeter, both from MISCO’s Bold North Audio Line. MISCO (Minneapolis Speaker Co.) is the oldest OEM driver manufacturer in the US, founded in 1949, and Bold North Audio is its new brand, launched in 2019 with a nearly exact replacement woofer for the ubiquitous Yamaha NS10 studio monitor, the 6.5” MS-10W featured in the February 2019 issue of Voice Coil and available here. The Bold North lineup was recently expanded to include a new 29mm dome tweeter, characterized in this edition, a woven carbon fiber 4" bass/midrange, and two new 6.5” XBL2 motor woofers.

This edition wraps-up with the usual dose of Industry Watch updates. The December 2020 edition of Voice Coil is available for download and already in the mail to print subscribers. Subscribers can go to - www.gotomyvcoil.com - to download this issue.

Remember, Voice Coil is available in print and download for all registered subscribers, free for industry professionals. To qualify for a free subscription to Voice Coil, or renew your subscription, go to: audioxpress.com/page/Voice-Coil-Subscriber-Services.html

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