Patent Review: Loudspeaker With a Wave Guide

This patent review looks at a “Loudspeaker with a Wave Guide” (Patent Number: US20140369543) by inventors Jussi Vaisanen and Ilpo Martikainen from Finish company Genelec. This patent relates to the Genelec 8351 Acoustically Coaxial Smart Active Monitor (SAM) monitor, originally launched in 2016. Later in 2017, Genelec expanded the concept into a complete series of Coaxial Active Monitors, “The Ones”. This article was originally published in Voice Coil, February 2015.

James Croft looks at an interesting new patent covering a “Compact Stand-Alone Stereo Loudspeaker” by inventor Jes Mosgaard from Libratone A/S (Denmark). This patent submitted in 2010, was granted in 2013, and describes a compact and portable stereo loudspeaker system that is capable of providing a spacious sound field using an internal stereo pair of loudspeakers arranged in a dipole configuration. This article was originally published in Voice Coil, February 2015.

Looking forward to serving the loudspeaker industry for another year, Voice Coil starts strong with a focus on Headphone OEM Devices and Parts, and a Spotlight article on speaker design, written by Brian Cho, the CEO of Resonado Labs. In his first Acoustic Patents column for 2021, James Croft writes about a signal processing system, allowing users to control a lower frequency acoustic range of a loudspeaker system, and Vance Dickason kicks off his Test Bench characterizations with the new Bold North Audio BWX-6502 Midbass, and the Wavecor TW022WA09 22mm textile dome tweeter.

James Croft reviews a patent claimed by Polk Audio and granted in 2015, describing “a single-enclosure loudspeaker system that projects multichannel surround sound into a listener’s room, and so replaces multiple conventional surround channel loudspeakers.” The patent also describes, in one embodiment of the invention, that the “surround channel program material is pre-processed by an integrated wireless transmission device that performs certain digital signal processing and channel mixing steps in advance of wireless surround signal broadcast to a receiver.” This article was originally published in Voice Coil, January 2015.

Every month on his Voice Coil's Acoustic Patents column, James Croft (Croft Acoustical) discusses different loudspeaker patents and inventions that are relevant to the audio industry. In the January 2015 edition. Croft reviewed a “Loudspeaker for Eliminating a Frequency Response Dip” patent, granted in November 12, 2014 to Harman International Industries, describing “a speaker system that includes a speaker enclosure having a front end, a rear end, and a first transducer. This article was originally published in Voice Coil, January 2015.

The March 2020 edition of Voice Coil is now available online and in print. In this edition, Vance Dickason gets hands-on with the Audio Precision APx500 Flex Audio Analyzer, Mike Klasco writes about Loudspeaker Enclosure Materials, and James Croft explores a new patent of a novel orientation of a cardioid speaker design. And in Test Bench, Dickason characterizes a home audio transducer from Eastech's Punktkilde line, the cosmetically pleasing AUGWL0016-JN02 6.5” midbass driver.

Voice Coil January 2020 is now available in print and digital. This first edition of 2020 includes two valuable directories of headphone and headphone parts vendors. In Acoustic Patents, James Croft reviews two different ported tweeter design patents awarded to the same inventor. And Vance Dickason welcomes two new companies - LaVoce from Italy and Oberton from Bulgaria - to Test Bench. LaVoce submitted the 1” DF10.172K compression driver, while Oberton sent the ND72CT/HB 1.4” Hybrid Dome compression driver.

This Voice Coil’s Spotlight, written by Vance Dickason with commentary from Floyd Toole, Wolfgang Klippel, Andrew Jones, and James Croft, focuses on Zero Phase in Studio Monitors. As Dickason explains, "the implication of using FIR filters to zero out the phase of a loudspeaker to improve its subjective performance seems inherently flawed given all the research done over years that concluded that the human ear is not very sensitive to phase or group delay." This article was originally published in Voice Coil, October 2019.

The October 2019 edition of Voice Coil is packed full of essential reading material. Vance Dickason discusses Zero Phase in Studio Monitors with commentary from industry experts. In Acoustic Patents, a new Speaker Structure design patented by Yamaha, and a new Passive Acoustic Radiator Module, invented by Joseph Sahyoun are under review. And Test Bench characterizes a new high power coaxial compression driver and horn from B&C Speakers, and a 28 mm silk dome tweeter from Trueanalog. Now available to download!

Heading for the 2019 CEDIA Expo, where the Voice Coil team will be in full force, the September 2019 edition features an interesting overview of a new Multi-Driver Loudspeaker with Cross-Coupled Dual Wave-Columns patent, recently sold to Dolby Labs, and a close look at previous tapped wave-column design efforts. In Test Bench, Vance Dickason characterizes the new PD.124NR1 12” neodymium midbass driver from Precision Devices and from Eastech’s Punktkilde line, the FSA044010-0802, a 1” titanium dome tweeter. Voice Coil September 2019 is now available for download, together with all the industry news and updates.