Test Bench: The AMT200P Pro Sound AMT and XMT200 Horn from Eighteen Sound

This Test Bench article characterizes Eighteen Sound’s AMT200P Air Motion Transformer and accompanying XMT200 6.5” waveguide. This driver is the brand's latest entry into the high-frequency transducer category, specifically designed for the pro sound community. The Eighteen Sound AMT200P includes a rectangular throat with a Kapton diaphragm with a neodymium magnet structure, and is rated for a power handling of 90W AES above 1.2kHz, with a sensitivity of 105dB, and a recommended crossover frequency of 1.2kHz at 48dB/octave. While the AMT200P can be used as a standard planar device it can be also coupled with a dedicated constant directivity horn, the 90°x 20° XMT200, featured in the characterization.

Martin Audio has extended its list of notable patents with the addition of a United Kingdom Patent for its XE stage monitor waveguide. The patent covers the use of Martin Audio’s differential dispersion coaxial drive units and the continuation of their waveguide shape to form the baffle, as seen in the XE monitors to achieve the desired HF coverage. The geometry of the static HF horn, the LF cone/moving waveguides and the static baffle combine to form a single HF horn.

Allen Sides' Ocean Way Audio announced its new Pro3 monitor (nicknamed 'Fat Boy'), the latest addition to the company's high-resolution monitor line. The new two-way active monitor system is its most compact design and delivers a frequency response of 45Hz to 20kHz and 110 dB maximum SPL between channels. A nearfield monitor designed for project and commercial recording studios, as well as in professional broadcast and post facilities where optimal performance is required, and space is at a premium.

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.

For this edition of The Audio Voice, I intended to focus a bit more on the latest developments in the fascinating world of sensors and how it impacts product development and design in all applications areas, particularly in consumer electronics, automotive, and health applications. After writing previously about Apple - the sensors on the Apple Watch and the surprising firmware updates for the AirPod Pro earbuds - I really didn't want to go back to Apple. But as always, Apple has a way of surprising us exactly when we least expected, and the company made another important audio announcement.

The market leader in touring, music festivals and large scale live music events, French manufacturer L-Acoustics has unveiled the latest reference in its family of sound reinforcement systems. Positioned above the compact Kiva and Kara line arrays, and the massive K2 and K1 full-range enclosures, the new L-Acoustics K3 completes the K Series lineup, offering a versatile solution for a reshaped events industry.

In this article, Vance Dickason measures the Radian Audio Engineering's LT6 Horn-Loaded Ribbon Device, part of an expanding series designed by 35-year loudspeaker engineering veteran Igor Levitsky for the Californian manufacturer. The LT6 is a pro sound driver but was designed to be a more hi-fidelity substitute for 1" compression drivers, and that is a direct result of Levitsky extensive experience in designing high-end residential, and cinema sound systems. This article was originally published in Voice Coil, June 2020.

The August 2020 edition of Voice Coil magazine opens with a great article by Igor Levitsky on “The Advantages of Thin-Film High-Frequency Transducers,” followed by a tutorial on voice coils by Mike Klasco, and an updated directory of vendors. James Croft reviews a speaker design patent from Panasonic, and Vance Dickason places the LT2 ribbon transducer and waveguide from Radian Audio Engineering, and the 140FCD 1" compression driver from REDCATT on his Test Bench.

Designed and engineered in JBL’s engineering facility in Northridge, California, the new JBL HDI Series features two floorstanding loudspeakers, a center channel speaker, a bookshelf model, and a powered subwoofer. The series is named after its patented High-Definition Imaging (HDI) waveguide, coupled with a family of patented compression drivers, and patented low and mid frequency transducers, allowing for powerful dynamics and accurate sound reproduction. Thoughtful, modern curved cabinets with quality finishes with magnetically attached grilles complete the designs.

November 2019 marks Voice Coil’s 33rd year as an information resource for the loudspeaker industry. For this edition, Mike Klasco focuses on "Measurement Microphones: Today and Tomorrow," while Nora Wong provides another valuable updated directory of Test & Measurement Microphone manufacturers and suppliers. James Croft reviews a new coaxial loudspeaker assembly patent granted to Tymphany, while Vance Dickason characterizes the DMA80-4, a 3" full-range speaker from Dayton Audio, and the AUGDL0003-JN03, a 1” magnesium-lithium alloy dome tweeter from Eastech’s Punktkilde line.