In this August 2023 issue of Voice Coil, Peter Larsen (Loudsoft) offers the second part of his "A FINE Circle Hardware/Software Tutorial." The target design is a two-way speaker with a 6.5" woofer and a 1" dome tweeter. Having previously explained the woofer design, in this second article, Peter Larsen explains the process for a 1” silk dome tweeter. All designed with the Loudsoft FINE Circle programs, using the Loudsoft FINECone diaphragm simulation software, combined with FINEMotor, and finally the FINE R+D analyzer, among other tools.For this issue, our readers will be able to explore another valuable directory of Voice Coil Winders and Converters 2023, compiled by Nora Wong. This includes US Voice Coil Winders, Asian Voice Coil Winders, European Voice Coil Manufacturers, Converters & Lead Out Wire, and Magnetic Fluid Suppliers.
Complementing this key supply area for the loudspeaker industry, Mike Klasco offers an updated directory of Magnet Vendors and Distributors Directory 2023. This includes some of the more relevant and popular companies that work with the speaker industry, organized into magnet vendors, plate and structure forgers, and key material vendors including fluids for magnet circuits and even test instrumentation and magnetizers.
For this issue's Acoustic Patents article, James Croft reviews a patent titled "Diaphragm for Use in Audio Transducer and Method of Manufacturing Diaphragm." This work, attributed to George Bullimore, Garry Taylor, and Stuart Hancock, on behalf of Tymphany Acoustic Technology, Ltd. (Taipei, Taiwan) was granted in May 2022 and describes a speaker diaphragm combining a top and bottom outer surface and a support layer using a honeycomb cell structure, which may be filled with a liquid resin or powdered material to improve the damping effect and reduce unwanted resonances. This patent is the result of the work of Tymphany's experienced transducer engineering team and seeks to provide an improved speaker cone that aims to minimize diaphragm mass while providing an optimal level of stiffness.
And, Vance Dickason offers another generous dose of Test Bench characterizations, starting with the 10NMFS 10" subwoofer from Beyma's recently announced Near and Mid Field (NMF) line. Apart from compact woofers, this new NMF range includes dome tweeters (T-25M and T-25S), which were already featured in the December 2022 issue of Voice Coil and are designed by Beyma’s newest engineer Diego Ivars (formerly a SEAS transducer engineer). This woofer aimed at the studio/home audio market, is one of three with a similar feature set that includes carbon fiber cones and dust caps, Malt Cross cooling technology, triple aluminum, and copper shorting rings, dual Bimax spiders, and Quattro inside/outside voice coil windings.
The 10" 10NMFS subwoofer now featured in this Test Bench uses a proprietary octagonal-shaped frame with five fairly wide twin spokes with 10 rectangular vent holes for enhanced voice coil cooling, with additional cooling provided by Beyma's Malt Cross forced convention cooling system that includes using the aluminum shorting ring as part of the cooling process. The cone and dust cap assembly are carbon fiber, with a convex roll articulated NBR surround, with slanted articulations.
The second Test Bench article offers a characterization of the Wavecor WF182BD13-04 7" midbass woofer, the 4Ω version of this model, part of a recent release of new high-end OEM drivers from the company. The April 2023 issue of Voice Coil featured the new TW045WA01 ceramic aluminum/cloth dome tweeter. The WF182BD13 is a midbass driver that utilizes a unique proprietary cone material made with interwoven Kevlar/Carbon fibers with beneficial properties for midrange reproduction - a combination of low mass, rigidness, and damping. The proprietary eight-spoke cast-aluminum frame is substantially open below the spider mounting shelf for voice coil cooling. Other features include a unique vented inverted dome-type phase plug (no dust cap), a shallow profile low loss high Qm NBR surround, accompanied by a flat 4” diameter black cloth spider. All of this is driven by a 1.25" diameter two-layer voice coil on a vented black fiber glass former. The Wavecor balanced driver T-pole motor system powering the cone assembly utilizes a ferrite magnet sandwiched between a black emissive-coated front plate and a black emissive coated and shaped T-yoke that incorporates a flared pole vent for additional cooling.
And this exceptional issue provides a third serving of Test Bench, where Vance Dickason measures the Scan-Speak 18ME/9642T00 Ellipticor 6.5" Midrange. This is the first driver to be offered only to Scan-Speak's OEM customers, not available on the DIY retail market. Benefiting from the oval (elliptical) voice coil shape that characterizes the Ellipticor range, the 18ME/9642T00 midrange also features the AirCirc motor structure, six neodymium magnet slugs in a circular array with copper shorting rings, and a vented titanium voice coil former wound with round copper wire, all part of the patented Symmetrical Drive SD-2 motor format. Other features include an uncoated paper cone and uncoated paper elliptical dust cap. While the 18ME has the similar 4” diameter flat cloth spider as the 18WE, the midrange’s surround departs from the typical NBR Scan-Speak woofer surround and as with the new 38WE 15" woofer, has a coated pleated M-type cloth surround similar to those used in pro audio.
This August 2023 issue is complemented as always with the Industry Watch section.
This issue of Voice Coil is available for download and already in the mail to print subscribers. Subscribers can go to - www.gotomyvcoil.com - to download this issue.
Remember, Voice Coil is available in print and download for all registered subscribers, free for industry professionals. To qualify for a free subscription to Voice Coil, or renew your subscription, go to: Voice Coil Subscriber Services.
To access the digital subscription platform, just login using your subscriber number and post/zip code as displayed on your mailing label.
