Test Bench: The AT60NC-4 AMT Tweeter from SB Acoustics’ Satori Line

The new AT60NC-4 AMT tweeter from SB Acoustics’ Satori Line follows the recent “renaissance” of Air Motion Transformer (AMT or Air Velocity Transformer aka AVT) over the last several years. The Satori AT60CN-4 is targeted at high-end audio applications. Its features include a damped foil and Kapton 43mm × 29mm pleated AMT diaphragm, with an optimized rear chamber, and two-part face plate. This article was originally published in Voice Coil, March 2021.

In earlier editions, Voice Coil introduced the Scan-Speak Ellipticor drivers with its unique oval voice coil shapes to defeat cone and dome standing wave modes. With the design and concept becoming extremely popular in the high-end two-channel market, the elliptical-shaped series of Scan-Speak drivers continues to expand. The new D2404/552000 Ellipticor 24mm tweeter is the little brother to the D3404 tweeter. This article was originally published in Voice Coil, March 2021.

The driver to be characterized in this article is Wavecor’s FR070WA05, a 2.75" full-range driver with a black anodized aluminum cone, built on a proprietary injection-molded polymer four-spoke frame. Like most contemporary drivers, the area below the spider mounting shelf is totally open for increased cooling. Powering the cone assembly is a dual neodymium motor. This article was originally published in Voice Coil, February 2021.

The AUGWL0006-JN01 is a new 2.25" woofer from Eastech’s Punktkilde lineup. With a depth of 7/8", the AUGWL0006-JN01 is part of the Ultra-Thin Series. The feature set is rather clever, using a black anodized aluminum cone assembly and dust cap, suspended with a NBR surround. A 25mm round foam surround supplies the additional compliance, and a large 35.5mm diameter under hung voice coil rides inside a double set of neodymium ring magnets. This article was originally published in Voice Coil, February 2021.

In this article, Vance Dickason characterizes the Bold North Audio BWX-6502 Midbass, which comes from a series of exciting new drivers designed and manufactured in the US by MISCO (Minneapolis Speaker Company). The BWX-6502 is built on the same platform with a similar XBL2 "dual-gap" motor design structure to the BWX-6501 model but with a cone assembly consisting of an Abaca fiber (paper) cone and a 60mm (2.4") diameter Abaca fiber dust cap, with compliance provided by a wide high excursion NBR surround, and a 3.5" diameter flat cotton spider (damper). This article was originally published in Voice Coil, January 2021.

For this edition of Test Bench, Vance Dickason characterizes the new BDT-2901 High-End Silk Dome Tweeter, from MISCO’s Bold North Audio Line. This is a high performance 29mm soft dome tweeter, designed to meet requests for a precision tweeter with a low crossover point, ideal for use in a two-way system paired with a 6.5” or 8” woofer. This article was originally published in Voice Coil, December 2020.

This Test Bench characterizes the very recent BWX-6501 Midbass driver from MISCO’s Bold North Audio Line. MISCO (Minneapolis Speaker Co.) is the oldest OEM driver manufacturer in the US, founded in 1949, and Bold North Audio is its new brand, launched in 2019. The Bold North lineup was recently expanded to include two new 6.5” XBL2 motor woofers. These new models, all designed and manufactured in MISCO’s own facility in St. Paul, Minnesota, feature dual inside-outside copper shorting rings in the motor to greatly reduce distortion. This article was originally published in Voice Coil, December 2020.

The driver under test in this Test bench is the SDx10 home audio woofer from Creative Sound Solutions (CSS) Audio, using XBL^2 dual gap motor technology licensed from inventor Dan Wiggins. The CSS SDx10 also has a well-appointed feature set that includes a very stiff coated black paper/carbon fiber blended composite cone with a convex black hard paper dust cap, NBR surround, and semi-progressive cloth spider. All this is driven by a (2.4" six-layer voice coil with two 12mm thick ferrite magnets sandwiched between a thick XBL-configured front plate and black-plated thick T-yoke. This article was originally published in Voice Coil, November 2020.

For this edition of Vance Dickason's Test Bench, the characterization centers on the brand new NERO-6MRN150D pro audio 6.5" midrange from SB Audience, the recently announced brand from Sinar Baja Electric (SB Acoustics). The new NERO-6MRN150D features a proprietary four-spoke-cast aluminum frame with efficient cooling, a curvilinear paper/graphite composite cone and large convex paper dust cap. The motor design combines a FEA-designed neodymium ring magnet and 49.5mm diameter voice coil wound with round CCAW on a non-conducting glass fiber former. This article was originally published in Voice Coil, November 2020.

The February 2021 edition of Voice Coil offers an overview of the Cone Industry in 2021, with an updated directory of loudspeaker cone, diaphragms and suppliers of relevant materials and components. Next up, James Croft reviews an interesting patent for a "Directional Loudspeaker," claimed by Dutch & Dutch BV, and Vance Dickason focuses his measurements on two small-sized drivers, typical of today's most popular consumer products. The first in Test Bench is the Wavecor FR070WA05, a 2.75" aluminum cone full-range driver, and the second is the AUGWL0006-JN01, a new 2.25" woofer from Eastech’s Punktkilde lineup.