Loudspeaker Failures and Protections (Part 1)

A new generation of effective and powerful speaker protection technology, using literally all the capabilities and power of pro sound rackmount loudspeaker management processors, is now being designed into mobile audio products that use very small loudspeakers. The implications are that mobile consumer electronics are going to play louder and sound better than ever. But to optimize speakers this way, we need to understand what causes loudspeakers to fail. This article was published originally in audioXpress, August 2013.

Voice applications are currently fostering the largest growth in the audio industry. This article addresses the challenges and solutions for testing the wider class of “smart” – connected, voice-activated, and sensor-equipped – devices, proposing solutions to implement basic acoustic tests and real-world tests of greater complexity. This article was originally published in audioXpress, April 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.

In this final article of the four-part series, Andy Lewis expands upon the Back EMF concepts hinted at in the previous three articles in this series. This article explores the Electrical and Newtonian filters and their intersections, observations on reactive parallel filters as pertains to Back EMF and energy losses. The theories can be applied to virtually all areas of loudspeaker design. This article was originally published in audioXpress, November 2018.

In the third article of the four-part series, Andy Lewis continues his fascinating exploration of Back EMF Phase Relationships in Moving-Coil Loudspeakers. The author discusses what causes Back EMF to simulate inductor, capacitor, or resistor (LCR) components, and explores the concept of slip, in order to explain how and why it causes the impedance to be inductive, resistive, or capacitive, depending on frequency. This article was originally published in audioXpress, July 2018

In this article series, Andy Lewis explores the generation of Back EMF in the region of a loudspeaker’s resonance. In this second article of the four-part series, he performs simple “thought experiments” to make qualitative observations about the activity of a moving-coil driver in the region of its resonance. This article was originally published in audioXpress, June 2018

In this article, Andy Lewis explores the generation of Back EMF in the region of a loudspeaker’s resonance. He also demonstrates a method for calculating the position of the moving assembly (or “cone”) relative to input signal, using complex impedance measurements. This article - part of a four part series - was originally published in audioXpress, May 2018

This article explains the methods of cutting disc records, the characteristics of magnetic phono cartridges, and how their combined response determines the required playback equalization. The article is based on a paper the author presented at the May 1996 conference of the Association for Recorded Sound Collections (ARSC) in Kansas City, and was first published in the Fall 1996 issue of the ARSC Journal. Later, the article was featured as part of "The LP Is Back!" compilation book published in 1999 by The Audio Amateur company.

This article shares a new important insight on modern Class-D amplification from the experienced perspective of Jens Tybo Jensen - part of the founding team at Merus Audio, and now head of Class D Audio Marketing and Applications at Infineon. The author states that it may be time to rethink Class D audio design and measurement practices, and he details what multilevel Class D amplification can do for new product designs. This article was originally published in audioXpress, October 2019.

In this article for Voice Coil, the authors explore the problem of designing vented enclosures, describing a backward concept they call LoVE BASS, which they found to save a substantial amount of engineering hours during the process of speaker box design. As opposed to taking a given driver and designing an enclosure, the authors define the system’s target performance in terms of physical volume, lower cut-off frequency, ripple and maximum achievable SPL, after which they look for candidate drivers that allow for such a design. This article was originally published in Voice Coil, July 2019.