Test Bench: The BWX-6501 Midbass from MISCO’s Bold North Audio Line

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.

On this Test Bench, Vance Dickason offers a characterization of the ODT29 fabric dome tweeter from Omega Audio, an OEM transducer manufacturer new to the pages of Voice Coil. The company, headquartered in Holon, Israel, was founded in 1978 when the founder of Omega Audio, Levi Mordechai left Morel. All of Omega Audio’s ODT line of tweeters, dome midranges are handmade in the company's facility, from dome coating to coil winding and motor assembly. This article was originally published in Voice Coil, October 2020.

This Test Bench article focuses on the Scan-Speak Ellipticor 21WE/4542T00 midrange woofer, an impressive looking driver. The motor design for the Ellipticor 21WE/4542T00 is again an AirCirc multi-magnet and patented SD design, using an elliptical two-layer voice coil wound with round copper wire on a titanium former. Motor parts include polished front and back plates for the neodymium magnets that incorporates a 12 mm diameter rear vent for additional cooling. This article was originally published in Voice Coil, October 2020.

We looked at the most-read articles of 2020 in audioXpress.com (which also includes selected articles from Voice Coil magazine), and we created this Top 10 list of news stories and online articles. 2020 was another record-breaking year for audioXpress.com, with visitors from all over the world returning often to read the more than 6,600 stories available. Which of the topics and stories published online in 2020 were the most popular? Here are the results!

In this Test Bench article, Vance Dickason focused on a home audio TeXtreme diaphragm tweeter from SB Acoustics' Satori line, the TW29TXN-B-4. What makes this tweeter so special is that it has a new TeXtreme diaphragm, a novel type of material that is used in applications that require a high degree of stiffness performance in combination with ultra-light weight. This article was originally published in Voice Coil, September 2020.

Keysight Technologies announced the new Infiniium 8-channel oscilloscope technology. Keysight's Infiniium EXR-Series Mixed Signal Oscilloscopes include eight models ranging from 500 MHz to 2.5 GHz and either 4 or 8 channels with wide-ranging upgradeability. The EXR-Series' waveform update rate is >200,000 waveforms/sec., allowing it to quickly build eye-diagrams capturing 5.7 Million UIs. Powerful and intuitive, the new oscilloscope series reduces test bench and workflow complexity.

For this Test Bench, Vance Dickason characterized the LT2 Ribbon Transducer and corresponding waveguide from Radian Audio Engineering. This is effectively a smaller version of the LT6 ribbon transducer reviewed in the July 2020 issue of Voice Coil, but offering much more diverse possibilities, as Vance Dickason discovers. And as the compact LT2 shows, this was designed to be more of a hi-fi or home theater substitute for any high frequency driver. This article was originally published in Voice Coil, August 2020.