Sound Control: The Ubiquitous Helmholtz Resonator

Our readers that follow Richard Honeycutt's column Sound Control know how this series of articles covers the most fundamental topics in acoustics and electroacoustics. Most people who have been around acoustics or acousticians have heard of the Helmholtz resonator. In this article, Honeycutt discusses the extraordinary scientist for whom this device is named - Hermann Ludwig Ferdinand von Helmholtz (1821–1894) - and examines how the resonator works, as well as its uses. This article was originally published in audioXpress, January 2017.

In its Standards Review article series, audioXpress published a two-part feature about the SuperSpeed USB 10 Gbps (USB 3.1 Gen 2) specification, the new USB Type-C interface, and Thunderbolt 3 technology. The second part examines how these technologies have evolved, how they work together, and the implications of USB Audio Device Class 3.0 specification, which standardized audio over USB Type-C. These two articles were originally published in audioXpress, December 2016 and January 2017.

One of the leading names in NFMI is FreeLinc Technologies, a research and development company focused on the adoption of this technology as a new wireless standard in the Public Safety, Military, Healthcare, and Consumer markets. For its January 2017 issue, audioXpress invited Dr. Michael Abrams, Freelinc’s Chief Executive Officer, to share his valuable perspective about the role of NFMI in wireless audio applications.

This edition of Voice Coil Test Bench characterizes the 6.5” 6MBX44 driver, from Italian pro sound OEM, B&C Speakers. The new MBX series of pro sound mid-bass woofers is especially well suited for small two-way loudspeaker applications. Features for the 6MBX44 include a proprietary four twin spoke cast-aluminum frame, enhanced voice coil cooling, curvilinear waterproof paper cone and inverted paper dust cap, and a neodymium ring magnet. This article was published originally in Voice Coil, January 2017.

The subject of this Test Bench is the recent SB Acoustics 6.5” MR16P-4 Satori midrange, which is nominally a midrange version of the SB Acoustics MW16R-4 (first reviewed in the November 2011 issue of Voice Coil) with higher sensitivity and shorter Xmax. The original Satori MW16R, while looking cosmetically similar to the Scan-Speak Illuminator 18WU series, was a well-designed driver that has established itself as a true high-end home audio competitor. This article was published originally in Voice Coil, January 2017.

This Voice Coil Spotlight by Marian Liebig (Klippel GmbH), discusses the specific challenges of Testing Mobile Devices such as Bluetooth headphones, smartphones, and tablets. Those devices have become part of people’s daily lives but increasingly pose important new challenges in terms of quality assurance, where defect symptoms need to be detected sensitively and quickly while measured under tough acoustical conditions.

audioXpress January 2017 featured the much-anticipated review of the brand new Kii Three speakers from the company everyone’s watching, Kii Audio. “The Next Step in Loudspeaker Evolution,” as Jan Didden and Paul Wilke titled their review, examines whether the Kii Threes are effectively “the most advanced loudspeaker on the market today,” as is claimed by Kii Audio. Learn what they discovered in this definitive review, now available online here.

In this edition, we kick off 2017 with an overview of what the 2017 NAMM and Integrated Systems Europe (ISE) trade shows might bring. This month's Spotlight features an important article by Marian Liebig (Klippel), discussing the specific challenges of Testing Mobile Devices such as Bluetooth headphones and smartphones. Vance Dickason test the SB Acoustics 6.5” MR16P-4 Satori midrange, and the 6.5” 6MBX44 midwoofer from B&C Speakers.

audioXpress January 2017 is now available. This month, we review Kii Audio’s new Kii Three speakers, and report on the most interesting new products at The Rocky Mountain Audio Fest (RMAF) 2016. We explore Near Field Magnetic Induction (NFMI) wireless audio applications, and the new USB Audio Device Class 3.0 specification for USB Type-C. We discuss streaming DSD over the Internet, revisit the Helmholtz resonator, explain how to build a Low-Power, Class-A Power Amplifier, and interview Michael Carnes of Exponential Audio. There is a lot to read inside this issue!