Progress on Calculating Edge Effect of Acoustical Absorption

For his audioXpress monthly column Sound Control, Richard Honeycutt explored new methods to calculate the edge effect of acoustical absorption and the research behind these methods. The research focuses on the recognized fact that rooms in which Reverberation Time (RT) is important, requiring the application of absorptive wall panels, seem to achieve better results when the absorptive material is applied only to parts of each wall. The physical reasons behind this apparent anomaly are often lumped into the category of "edge effect." This article was originally published in audioXpress, December 2017.

Continuing audioXpress' Amplifier Series, looking at the latest technologies and Class-D amplification platforms, Ward Maas writes about Axign, a new company from The Netherlands, founded by former Philips and NXP employees who worked on the pioneering Class-D efforts. Established in 2014, their efforts have resulted in the development of the AX5689m a Class-D audio amplifier controller chip in a QFN package. audioXpress visited the company to find out more and to receive a demo. This article was originally published in audioxpress, December 2017.

In this article, published by audioXpress in December 2017, Oliver Masciarotte explores the Naim Mu-so Qb Wireless Music System, with its stunning design, glass-filled polymer casing, and the same clever digital brain as the original Mu-so. Is this indeed a model for what complete wireless integrated audio systems can do? Kent Peterson (Warkwyn) puts the Mu-so Qb to the test confirming that the device sounds as good as it looks. This article was originally published in audioXpress, December 2017.

The driver for this month’s Test Bench explication came from a German OEM driver manufacturer and is from Eton’s home audio Orchestra line of drivers. I asked Eton to send a model from this line, the 4-512/C8/25 RP, mostly because of the unique cone. All of the cones in the Orchestra line are serrated paper cones, which is somewhat reminiscent of the orange sliced paper cones in the Scan-Speak Revelator line. This article was originally published in Voice Coil, December 2017.

Beginning with the January 2018 issue of Voice Coil magazine, Vance DIckason implemented the Loudsoft FINE R+D analyzer into the Test Bench measurement protocol. This article provides details about the features in FINE R+D FINE R+D, a Fast Fourier Transform (FFT) analyzer packaged in a 1u rack, which is used with the recommended G.R.A.S. 0.25” Type 46BE microphone capsule and preamplifier body. This article was originally published in Voice Coil, December 2017.

Physical Lab, based in Senden, Germany, is a fascinating company in that it not only manufactures loudspeaker test solutions directly aimed at speaker development and research, but also provides several engineering services for the loudspeaker industry. This article highlights the three loudspeaker measurement accessories that Physical Lab manufactures — the Physical Lab Mini Reference Amplifier, the Physical Lab Imp Box, and the Physical Lab ISO Box. The article was originally published in Voice Coil, December 2017.

Based out of the Rocky Mountains of Salt Lake City, UT, a band of musicians, engineers, and enthusiasts with a desire to make great products, designed a way to give new life to vintage and modern microphones. The Simply Sound Company, designed its SS-1 single channel preamp, meant to boost the signal of a low output microphone to levels compatible with normal mic inputs. This article was originally published in audioXpress, December 2017.

Don't miss Mike Klasco's overview of the latest trends in Audio Digital Signal Processing, a review of a new "knurled diaphragm," patent for planar magnetic drivers, and a User Report on LOUDSOFT's FINE R+D Analyzer, which, from 2018, will be implemented into the Test Bench measurement protocol. In Test Bench, learn more about a bass-midrange driver, and a woofer, from Eton and Volt, respectively.

Another great edition of audioXpress. Discover how well the Naim Audio Mu-so Qb Wireless Music System did in our in-depth review. Read about Axign, and how this Dutch company is revolutionizing Class-D efforts. Explore the ideal acoustic listening environment for dipolar and multi-directional speakers. Build an omni-directional coaxial speaker tower. Read an interview with Floyd Toole. And don’t miss the first part of our complete "Audio Editors Roundup." Now available online!