R&D Stories: Motion Feedback for Active Desktop Subwoofers

Zami Schwartzman, the founder of Servobass, shares his journey into the application of Motion Feedback (MFB) methods for active subwoofers. He explores passive and active bass enhancement methods and how Servobass arrived at an optimized design using MFB techniques to achieve highly performing active subwoofers in desktop and compact sizes. A solution that is now available to be licensed by the industry. This article was originally published in audioXpress, November 2023.

In the October 2023 issue of Voice Coil, James Croft reviews an active noise control enclosure system, and Mike Klasco and Nora Wong provide an updated directory of Integrated Electronics for Loudspeakers. Vance Dickason offers three different driver characterizations, starting with the AMT100H driver from Eighteen Sound. Next up, he tests an updated version of the popular TW030WA23/24 tweeter from Wavecor. And finally, measures the Scan-Speak D2008/2010, the revised version of the classic dome tweeter from the Danish brand.

Servobass is the trade name for the products and technology designed by Zami Schwartzman, and which will be making its debut at CES 2023. The company will demonstrate its Motion Feedback Desktop Subwoofers, a new shallow "under the seat" MFB car subwoofer, and its ZRS-1 class-D plate amplifier, and is open to licensing opportunities. Servobass will be at ALTI Association Hospitality Suite at CES 2023, Lido 3101B - Level 3 of the Venetian Expo and Convention Center, and at the Menlo Scientific suite.

In this article, Zami Schwartzman shares his personal journey to design and perfect his own accelerometer-based motion feedback desktop subwoofers, including plate amplifiers with MFB control, crossover and voice coil thermal protection that can be matched with any low frequency MFB driver. The proof of concept demonstrated the ability to perfectly complement popular active nearfield monitors, mitigating the effects of room reflection. This article was originally published in audioXpress, September 2022.

David Logvin explores the Lepai LP40PA ultra-compact amplifier, a versatile Class D common plate amp module with fully integrated Bluetooth 4.2 receiver and 3.5 mm stereo inputs, ideal for converting existing passive speakers into convenient portable and wireless units that can be placed anywhere. The Lepai LP40PA has plenty of power for a pair of bookshelf speakers as Logvin experimented. This article was originally published in audioXpress, January 2019.

The January 2019 (CES) edition of audioXpress has arrived. Read our Microphone Market Update, addressing the latest cutting-edge microphone technologies, and learn how Zylia created its ZM-1 spherical microphone array. Also in this edition, Joe D’Appolito explains how to address the equalization of closed-box subwoofers, Hans W. Gierlich writes about testing Smart Home Devices, David Logvin reviews the Lepai LP40PA plate amplifier, and George Ntanavaras describes a stereo analog preamplifier DIY project. Oh, and read Erik Owen's unique take on Rocky Mountain Audio Fest (RMAF) 2018.

Parts Express will join thousands of professional audiovisual enthusiasts in Orlando, Florida June 16-19 for the annual InfoComm show at Booth #535. Parts Express will showcase a range of new products from Dayton Audio, Talent Sound & Lighting and Talos Security, among several other brands.