Test Bench: Eighteen Sound NSD1095N Compression Driver and XT120 Horn

The NSD1095N is a 1" throat compression driver with a compact footprint for “high quality” sound applications in professional audio, from studio monitors or stage monitors to high-power sound reinforcement cabinets. It uses a field replaceable True Piston Motion (TPM) TiN coated titanium diaphragm, extending the frequency response by 25% and incorporates a proprietary phase plug architecture that has been designed to give a smooth coherent wave front at the horn entrance across the whole working frequency range.

As a respected manufacturer of high-quality condensers and crossover components, Mundorf is also capitalizing on the industry's “renaissance” in AMTs and now offers five models in this updated U series, each driver having the same width, but different heights. The U80W AMT model features a 63mm x 19mm pleated proprietary AMT diaphragm, an optimized rear chamber, a flat face plate with an optional secondary aluminum face plate, and is rated for 80W power handling and 94dB sensitivity. The U Series is the fourth in Mundorf's AMT portfolio. This article was originally published in Voice Coil, March 2022.

This article addresses the practical approach to testing and evaluation of multichannel MEMS microphone arrays. The simultaneous acquisition and measurement of signals from a microphone array presents a variety of challenges to developers seeking to evaluate their designs. This article explains the fundamentals to address challenges in smartphones, smart speakers, and all sorts of voice-activated devices, typically using two, and up to seven or more microphones. This article was originally published in audioXpress, March 2022.

Following the review of the KEF LS50 Meta speakers for audioXpress, this article offers a detailed review of the KC62 compact subwoofer, which combines KEF's force-canceling and Uni-Core technologies in a new approach to allow maximizing bass in a minimum space. Masciarotte did the listening and spoke with Jack Sharkey, Senior Technical Engineer at GP Acoustics, about this fascinating design. The subwoofer was also measured by Peterson at Warkwyn’s facility using the Klippel measurement system.

Adding a great perspective on the topic of test and measurement, in particular for production lines, this article makes the case for using web interfaces, and embrace web standards for automated testing of audio equipment. The founder of QuantAsylum advocates an open-design philosophy for controlling and querying things via REST, which stands for Representational State Transfer, a widely accepted set of guidelines for creating reliable web APIs and leveraging the know-how of millions of developers.

This article proposes a Sound Level Evaluation solution based on the popular Raspberry Pi 4 and the possibilities of using the Sfera Labs' Exo Sense Pi - a compact multi-sensor module - as a sound meter. The Exo Sense Pi combines several environmental sensors and connectivity options, and integrates a digital microphone which can be used to evaluate ambient noise levels or measuring noise sources. This article was originally published in audioXpress, March 2022.

Discussing speaker enclosures, this article examines all the different options for plastic applications and the implications for loudspeaker driver design in general. Enclosure characteristics, construction features, advantage comparisons between wood and wood particle board cabinets, and production techniques are some of the topics explored. This article was published in Voice Coil, March 2022.

audioXpress March 2022 Test and Measurement issue addresses the latest tools and solutions meeting real-world challenges in audio. This year's extensive Market Update report, offers a complete overview of all the audio test and measurement products and solutions released during the past 12 months. One of the major highlights was Echo Test + Measurement, with its modular, and highly cost-effective range of audio test interface solutions.

The March 2022 issue of Voice Coil offers a complete overview of loudspeaker cabinet design options, plastic enclosure materials, and production techniques, as well as an updated directory of Speaker Enclosure Vendors. This month, in Test Bench, Vance Dickason characterizes the Mundorf U80W from its latest U Series of Air Motion Transformers. And addressing demanding professional audio applications, this issue also includes a Test Bench on Eighteen Sound’s NSD1095N Compression Driver and XT120 Horn. Start reading online. Printed copies are on the way.

audioXpress March 2022 features an extensive Market Update report on the latest audio test and measurement tools. Matt Taylor explains the possibilities of REST for automated test and measurement, and Joe Begin (Audio Precision) addresses testing multichannel MEMS microphone arrays. The KEF KC62 subwoofer is reviewed by Oliver Masciarotte and measured by Kent Peterson, and Ben Chen explains how to use the Sfera Labs' Exo Sense Pi module as a sound meter. Download or read online now.