Test Bench: The Radian Audio 475BEPB-8 1" Beryllium Compression Driver

This Test Bench centers on the Materion beryllium version of the popular Radian Audio 475PB 1" ferrite motor compression driver, also available with Radian’s outstanding sounding proprietary aerospace-grade aluminum alloy. These beryllium diaphragms are produced by Radian at its Pomona, CA, facility under license from Materion. This Test Bench offers a comparison analysis of the aluminum alloy with the beryllium model. An insightful characterization for speaker builders, designers, and manufacturers. This article was originally published in Voice Coil, February 2023.

This article offers a detailed characterization of Wavecor's latest SW259WA01 High Xmax Subwoofer. This new 10.25” subwoofer has a generous feature set that includes a proprietary six-spoke cast-aluminum frame that is substantial enough to support the heavy ferrite motor assembly and incorporates 36 vents below the spider mounting shelf. Other features include a very stiff and thick flat profile aluminum cone, an ingenious motor system with enhanced cooling, and a 2" four-layer voice coil wound. This article was originally published in Voice Coil, February 2023.

In this two-part series, Ethan Winer examines current practices and methods for designing four-layer printed circuit boards using surface-mounted components (SMDs). A great article for our DIY readers and many developers who often are faced with the need to build and test their projects on a properly designed, prototype printed circuit board. Part 1 presents an overview of the process, while Part 2 he will explain specific strategies. Many related issues will be described along the way.

The Up2Stream Amp stereo streaming amplifier board from Arylic is a complete, affordable solution that invites integration by DIYers and system integrators for multiroom and wireless audio setups. This board is part of the large Arylic portfolio of audio products produced by Rakoit, a design house and OEM/ODM manufacturer with excellent credentials in digital and wireless audio. Stuart Yaniger attests to how this affordable and versatile solution performs and measures.

This review looks at a patent of parametric loudspeaker awarded in November 2016 to Luke Batchelder (Somers, NY), and J. Samuel Batchelder (Somers, NY) on behalf of Convey Technology, Inc. (Somers, NY). As James Croft (Croft Acoustical) comments in this patent review: "The parametric loudspeaker is one of those technologies that get rediscovered and “invented” about every 10 years." This article was originally published in Voice Coil, February 2017.

This article discusses a new patent-pending feature of Nureva’s next-generation technology for audio presentations and conferencing that provides a new perspective on how microphone coverage works in large meeting rooms. Erica Yorga, the Principal Intellectual Property manager at Nureva, details the unique features and benefits of the Unified Coverage Map technology for conference and lecture rooms. This article was originally published in audioXpress, February 2023.

The February 2023 issue of Voice Coil is now available and packed full or great content. Read the CES 2023 report, James Croft's review of the Quadrupole Transducer patent, and check out the latest Loudspeaker Cone/Diaphragm Industry Suppliers Directory. In this month's Test Bench, Vance Dickason spent time with the Wavecor SW259WA01 High Xmax Subwoofer and the 475BEPB-8 1” Beryllium Compression Driver from Radian Audio, covering the two frequency range extremes.

audioXpress February 2023 focuses on the small devices in the increasingly larger market of MEMS Microphones and Voice Pickup Sensors. The Market Update on this topic is complemented by Erica Yorga's article on the principles of Nureva's Unified Coverage Map. Ethan Winer offers the first of a primer on modern PC board design, there's a review of the Arylic Audio Up2Stream Amp V4 board, an inside story on how Crestron adopted AES67, and a High-Performance Tube Hybrid Preamp DIY project.