Test Bench: The BMS 1” 5530ND High-Efficiency Compression Driver

This Test Bench characterizes a new BMS compression driver, the 1” 5530ND, introduced at Prolight+Sound 2019, as a new generation offering a compact physical package that is only 72 mm in diameter, ultra-low intermodulation distortion ring diaphragm, and very high efficiency. This article was originally published in Voice Coil, December 2019.

In this Test Bench, the focus is the Dayton Audio DMA58-4, a new 2" full-range line array/smart speaker from Dayton Audio. DMA stands for Dual Magnet Aluminum Cone and the series already includes five models of full-range drivers, all using a proprietary 12-spoke injection-molded frame. This frame is very open to reduce reflections back into the cone and also has a very generous mounting flange making multiple driver arrays cosmetically attractive and compact. This article was originally published in Voice Coil, December 2019.

In this article for Voice Coil focused on MEMS loudspeakers, Mike Klasco reviews a bit of the history of the technology and previews the evolution and impact on the audio industry in general. The article examines MEMS devices in general, provides a basic explanation of how the various types of MEMS speakers work, and what commercialization challenges are ahead. This article was originally published in Voice Coil, December 2019.

Stuart Yaniger offers his review of the latest Audio Precision APx555 B Series audio analyzer, and the corresponding new updated V5 software for the APx series. The APx B series now features a new High Performance Sine Generator and a High Performance Sine Analyzer, which Audio Precision claims reduces THD+N to better than -120 dB, with a 1 MHz bandwidth and Fast Fourier Transforms (FFTs) of up to 1.2 million points. This article was published in audioXpress, December 2019.

Dario Cinanni details its acoustic simulation study about high-frequency horn driver transducers. Using a novel equation that correlates the matrix of a virtual horn and measured compression driver pressure, it is possible to easily predict the absolute sound pressure level (SPL) of the real horn driver frequency response. The results showed a good match between simulations and measurements up to 15 kHz. This article was originally published in Voice Coil, December 2019.

Voice Coil December 2019 features an outstanding article on constant directivity horn design from Dario Cinanni, followed by a new Spotlight feature on MEMS loudspeakers by Mike Klasco (Menlo Scientific), and a new vendors directory. Next up, James Croft reviews a new loudspeaker enclosure patent recently awarded to Bang & Olufsen, and Vance Dickason offers two complete characterizations of new pro sound drivers from Dayton Audio and BMS.

audioXpress December 2019 dives into the latest wireless audio and DSP platforms and solutions in a dedicated Market Update, followed by a review of the latest Audio Precision APx555 B Series audio analyzer. David Logvin shares his experience with the xCORE VocalFusion development platform by XMOS, while Michael Steffes re-confirms a theory that cascaded amplifier + ADC harmonic distortion combine as voltage swings. Christopher Paul explores alternative approaches to the design of a linear current regulator for audio tube amplifiers, Menno van der Veen details an 18 W single-ended valve amplifier using Trans technology, and Richard Honeycutt investigates whether or not swapping out comparable tubes makes any audible difference in a guitar amplifier’s sound. Download your own copy now!