2018 seems to be the year of earphone and headphone test equipment. Headphones are one of the hottest audio categories and the industry is responding with new and improved solutions for all the industry’s needs, from research and development, evaluation and quality control of all the earphone- and headphone-related technologies, which increasingly includes sophisticated wireless technology systems, sensors, digital signal processing, and active noise canceling (ANC). This year, we have a great deal of activity, both in hardware development (e.g., artificial ears, head simulators, manikins, and related jigs and fixtures) and in the evolution of hardware analyzers and software. Because this is 2018 and wideband is already available on earphones and headphones, hearables are combining an increasing number of sensors, manufacturers want to implement increasingly sophisticated ANC and - to make things even more complicated - now there's even voice-activated commands. The headphone test applications are certainly getting more challenging and the manufacturers are responding. That's what we discuss in this technologies and solutions roundup, featuring Brüel & Kjær (B&K), Audio Precision, CRY Sound, G.R.A.S. Sound & Vibration, HEAD acoustics, Klippel, Larson Davis, Listen, Loudsoft, miniDSP, and SoundChip.
As part of our Headphone Focus, the April 2018 edition includes a thorough review of Audio Precision's AECM206 Binaural Headphone Test Fixture. For engineers developing and evaluating headphones, Audio Precision (AP) released this new headphone test fixture, a competitively priced IEC 60318-4-compliant accessory that simplifies earbud and headphone measurements in both lab and production environments. Stuart Yaniger puts the AECM206 unit to the test, uses it in real measurements of headphones and earphones, and shares the essentials about this complete measurement solution.
Although it relates to any audio measurement application, we include a detailed article about HEAD acoustics' labCORE, the German company's latest modular, multi-channel front-end measurement platform. Designed in response to modern measurement applications, labCORE enables users to configure optional modules, and thus, tailor the equipment to the exact measuring tasks, in headphones, speakers or sophisticated communication solutions.
Focusing more on the R&D angle, in "Developing a New Electrostatic Transducer," we discuss how Warwick Audio Technologies designed a completely new type of transducer for high-end electrostatic headphones using the latest materials and computer simulation tools from Comsol. The design process for the High-Precision Electrostatic Laminate (HPEL) transducer also inspired the team to build a completely optimized system, including electronics. The result is available in the outstanding Sonoma Model One, the world’s first headphones to use HPEL audio transducers.
We also have a very interesting DIY perspective for our readers. Ron Tipton discusses how to build an economical Head-Related Transfer Function (HRTF) binaural microphone head, starting with a Styrofoam wig holder and two Panasonic electret condenser microphone cartridges, type WM-61A.
Finally, in anticipation of our traditional Glass Audio issue in May, we kick-off the topic with a contribution by tube and amplifier expert, Menno van der Veen, discussing the TubeSociety 2A3-300B-SE Amplifiers. Menno van der Veen designed five challenging 300B-SE amplifiers for his students, who are learning to become the best designers and constructors of tube amplifiers. In Part 1 of this article, he explains how his TubeSociety academy in the Netherlands designed the first four amplifiers. The fifth amplifier, plus all about the power supplies and construction, will be featured in Part 2, set to run in the May issue of audioXpress.
This is certainly an edition of audioXpress to keep close by and use as reference for some time to come. You download audioXpress April 2018 now at: www.gotomyxpress.com
And of course you can also subscribe here: www.audioxpress.com/page/audioXpress-Subscription-Services.html
If you wish to buy a single printed issue or the complete audioXpress archive, from 2000 to 2018 (yes, include the latest issue) on USB, just visit our online shop at www.cc-webshop.com.