audioXpress November 2015 is one of those issues with a variety of great articles for everyone. We start with a feature on Mobile Audio from Mike Klasco and Steve Tatarunis. Smartphone audio, to be specific. This month, our experts were busy in the test lab measuring the performance of eight high-end smartphones. Following a discussion on the current state of smartphone audio playback, the challenge was to compare the audio quality of eight portable devices: one non-smartphone (the iconic iPod classic) and several smartphones known for high-quality audio including the iPhone 5 and the iPhone 6. Don’t miss the test results.Next, our Sound Control column, by Richard Honeycutt, focuses on Smartphone Apps for Sound Measurement. In this article, Richard explores some modern-day sound measurement apps that can be downloaded to most smartphones running iOS (Apple), Android, and Microsoft Windows. Some are just useful, others are fun to use, but many are surprising for the variety of tools and possibilities, especially when combining the mobile device with an external measurement microphone.
As for DIY audio articles, this month we bring you the first part of a great project by James Lin. The SRX Plus Hybrid Amplifier is a design for a tube amplifier that is able to drive the author’s Stax electrostatic headphones. James Lin bought the Stax SR-007 MKI headphones to accompany his old Stax SR-5s. “The SR-5 requires a bias of around 230 V, whereas the SR-007 requires a bias of around 580 V. I wanted a good amplifier that would be able to drive both headphones so I built a tube amplifier with solid-state support for electrostatic headphones,” he explains.
Next, is James B. Wood’s article on The PhaseBuster! James Wood is founder and board chairman of Inovonics, a 43-year manufacturer of audio and radio frequency products for broadcast and he holds several patents in the field. With the PhaseBuster project, his goal was to create a monaural mix from stereo without losing audible components; to process a stereo program for better mono compatibility, one that will sum to L+R mono with minimum degradation; to create a pseudo-stereo program from a monaural source; and to “spatialize” a stereo source, increasing the apparent soundstage width. This simple project provides all those possibilities.
For those interested in practical Test and Measurement, Stuart Yaniger is almost to the end of his amazing article series on “Sound Cards for Data Acquisition in Audio Measurements, in which he examined ways to create a low-cost system for lab-grade audio electronics measurements. This month he discusses a few measurement examples to illustrate the power and versatility of sound-card-based measurement.
We also highly recommend this month’s questions and answers with Simon Ashton, founder of AudioSmile. Simon is a young British speaker designer and entrepreneur with an impressive business and product portfolio. Among other speakers, he designed the amazing Little British Monitor, which he managed to successfully fund on Kickstarter.
Of course, we continue to explore the best solutions for experimenting with sound reproduction. This month, Ron Tipton continues to explore affordable (or free) software and hardware solutions for Binaural Sound from Two Loudspeakers.
Selecting the best components and the right circuit designs is key to avoid several common pitfalls when designing our own equipment. In “Passive Offenders,” Helmuth Lemme explains how to look for high-end components for high-end audio projects.
And continuing with Audio Electronics, this time focused on Hollow-State designs, Richard Honeycutt details “Some Background Information on Noise in Amplifiers.” Having discussed distortion and frequency response in previous articles, Richard now tackles noise.
As you can see, there are plenty of reasons to start exploring your new issue of audioXpress, now available at www.gotomyxpress.com
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