audioXpress - April 2018

8 State-of-the-Union of Earphone and Headphone Test Instrumentation
By Mike Klasco and J. Martins
This comprehensive roundup highlights the latest company trailblazers in the burgeoning earphone and headphone test equipment market.

28 Audio Precision AECM206 Headphone Test Fixture
Putting Headphones to the Test
By Stuart Yaniger
Stuart Yaniger put the AECM206 unit to the test to try and verify Audio Precision’s claims that it is equally capable in both R&D and production test applications and well-suited for testing circum-aural, supra-aural, and intra-concha headphones and earbuds.


36 Developing a New Electrostatic Transducer
By Valerio Marra
Learn more about Warwick Audio Technologies’ new type of transducer for high-end electrostatic headphones. The design process for the High-Precision Electrostatic Laminate (HPEL) transducer also inspired the team to build a completely optimized system, including electronics.

44 HEAD acoustics labCORE
A New Modular, Multi-Channel
Front-End Measurement Platform
By J. Martins
Discover labCORE, an all-new front-end platform from HEAD acoustics. labCORE is a modular multi-channel front end designed in response to modern measurement applications.
50 TubeSociety 2A3-300B-SE Amplifier Project (Part 1)
Experimentation Leads to Success
By Menno van der Veen
Menno van der Veen designed five challenging 300B-SE amplifiers for his students. Part 1 of this two-part article discusses his TubeSociety academy in the Netherlands and details the first four amplifiers.




60 A DIY HRTF Binaural Microphone Head
By Ron Tipton
Ron Tipton explains how to build an economical head-related transfer function (HRTF) binaural microphone head, using a Styrofoam wig holder.