The Latest in Loudspeaker Knowledge and Developments in Voice Coil October 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.

In this article, James Croft discusses a patent granted to Curtis Graber (Woodburn, IN) that describes a radial acoustic speaker assembly including a transducer and a plurality of segmented spiral horns acoustically coupled to the transducer, each with its acoustical path. This new patent by prolific audio inventor, Curtis Graber, uses a new multi-spiral waveguide structure driven by a single transducer and has clear advantages over prior art. This article was originally published in Voice Coil, May 2018.

The April 2023 issue of Voice Coil reveals the genesis of Echo Test + Measurement and its AIO Test System. As scheduled, there's an updated industry directory of Cable and Connector vendors, James Croft reviews a key Polk Audio patent that expands on its Polk SDA loudspeaker prior art now in a more compact enclosure. And on Test Bench, Vance Dickason focus on the characterization of the innovative TW045WA01 dual-diaphragm tweeter from Wavecor.

The brand new generation of Beyma compression drivers originates from an intense R&D effort and two patent-pending innovations. Unveiled at ISE 2013, Beyma's four base designs with 2 throat sizes, 4 voice coil diameters, 3 diaphragm materials and 2 magnet types, allow for a total of 12 new models (for now). Scheduled to be launched progressively during 2023, these new Beyma state-of-the-art high frequency transducers deliver new exciting possibilities for speaker designs.

The patent reviewed here was granted to inventors Robert G. Johnston (Amprior Ontario, CA), and Sanford M.Gross (Owings Mills, MD), respectively the head of engineering of GoldenEar Technology, and one of its co-founders. The patent describes a subwoofer with two drivers on each side plus one passive radiator facing up and one passive radiator facing down. The passive radiator facing down effectively couples acoustic energy at very low frequencies into the floor.

Happy 36th Anniversary Voice Coil! The November 2022 issue of Voice Coil once again celebrates the launch of this periodical as an information resource for the loudspeaker industry. Also, this month, Mike Klasco writes about technologies and solutions to enhance low-frequency performance, and James Croft reviews a recent patent awarded to Panasonic for a loudspeaker arrangement for a Near to the Ear Subwoofer in a car seat. For this month's Test Bench, Vance Dickason characterizes the 6CXN36 coaxial 6.5” pro sound driver from B&C Speakers, and Wavecor’s FR4X-6WA01 compact oval full-range driver. Now available in print, digital and online.

Voice Coil September 2022 offers an article about solutions for Smart Speakers and Voice Processing by Mike Klasco, and an updated directory of Magnet Vendors and Distributors for 2022. James Croft reviews a recent patent awarded to Tymphany for a new Coaxial Loudspeaker design, and Vance Dickason characterizes two very original drivers in Test Bench. The HF1460 compression driver from Faital Pro and the Tang band the W4-2356 4" full-range woofer with an off-centered voice coil.

In this article, James Croft looks at a patent awarded to David Russell (Toronto, CA); and John French (Caledon, East, CA) on behalf of Audera Acoustics, Inc., Schomberg CA. The patent describes a generic acoustic high displacement transducer system, containing a diaphragm position sensing module, a controller with a transmitter, so that the voice coil moves at least partially in response to the control signal.

August is traditionally the voice-coil-focused issue of Voice Coil, offering an always-valuable perspective on the state of the loudspeaker industry. In this issue, Mike Klasco discusses Audio Manufacturing in The Philippines, James Croft explores another key Mayht patent, and Vance Dickason measures and characterizes the B&C Speakers DE111-8 1" compression driver, and the MD60N-6 2.5” Dome Midrange from SB Acoustics' Satori line.

This article reviews a patent application submitted in 2010 by to two inventors, on behalf of Jazz Hipster Corp. (Taiwan), regarding an improved structure of a speaker using the surround to reduce the resistance of the diaphragm excursion, which helps to generate a more linear diaphragm movement, with less resistance, and reduced distortion. As James Croft noted, the approach had been used in the past, but its use decreased due to the high-performance achieved with well-designed roll-surrounds, at a lower cost. No surprisingly this patent was subsequently abandoned.