For Voice Coil February 2019, our team worked on all the latest information regarding cone and diaphragm technology, starting with an overview of the latest high-performance solutions. As Mike Klasco (Menlo Scientific, Ltd.) explains, new diaphragm materials for speakers, from woofers to tweeters, compression drivers and headphones, will always be a hot topic for Voice Coil. In this special focus article, he explores how the industry has been searching for lighter materials with higher Young’s modulus, evolving from paper to woven carbon fiber and new approaches that explore thin ply carbon materials, like Swedish advanced composite specialist Oxeon is attempting. Read all about it here.Next up, Klasco updated our Loudspeaker Cone Industry Suppliers directory for 2019, with an expanded scope to include relevant materials suppliers and component vendors such as specialized surrounds, spiders (dampers), and cone additives. A valuable directory with first-hand commentary of all entries from North America, Europe, China, and other Asian countries.
In a related follow-up, Nora Wong prepared an updated directory of Headphone/Earphone Parts vendors - the first of its kind - because this is a topic that we know is of great interest for Voice Coil readers. As Wong explains, headphones and earphones are firmly entrenched as a key audio product category and for speaker engineers now designing headphones, information on specific components and materials - from selection options to vendor sourcing - is scarce. Since we do not have the pages to list every injection molder and cable vendor, the directory selected key suppliers that either have a strong share of the business (usually for good reasons!), or up and coming alternatives that deserve their share of attention. The directory features headbands, ear cushions, ear tips, drivers, diaphragms, acoustic resistance woven and non-woven vendors.
Companies interested in being featured in the next update of this directory should get in touch by email - here.
For this month’s Acoustic Patents column, James Croft (Croft Acoustical) discusses a very recent patent of a “Head-Related Transfer Function Equalization and Transducer Aiming of Stereo Dimensional Array (SDA) Loudspeakers,” awarded to Scott Orth and Stuart W. Lumsden on behalf of Polk Audio, LLC (Vista, CA). The intriguing patent describes a very specific loudspeaker design that claims to be able to achieve better stereo sound reproduction with “a realistic ambient field and a larger, and more stable acoustic image.” As Croft explains in his detailed review, this obviously aims at achieving better crosstalk cancellation designs, something that Polk Audio actually patented nearly 40 years ago, with its original Stereo Dimensional Array (SDA) loudspeaker, and for which the new updated patent now provides a new improved version addressing the “Head Related Transfer Function” issue, not by implementing complex filtering, but primarily by reforming the front of the loudspeaker enclosure shape to more closely mimic the impact of acoustic waves “crosstalking” around a human face.
And finally, in Test Bench, Vance Dickason actually had lots of fun characterizing a new version of a legendary 6.5” woofer recently announced by MISCO (Minneapolis Speaker Company). The new MS-10W, will be marketed under the new MISCO brand, Bold North Audio, and it is effectively a direct replacement for the famous white driver on Yamaha’s NS10 studio monitors! The MS-10W is an extremely close replacement woofer and it actually includes a lightweight white flat profile seamed paper cone with a white paper convex dust cap. There is no pole venting or venting below the spider mounting shelf, and compliance is provided by a 12 mm wide coated cloth surround and a 3.25” diameter cupped cloth spider. The motor assembly is powered by a 16 mm × 89 mm ferrite magnet sandwiched between 5 mm front and back plates. Driving the cone assembly is a voice coil that consists of a 32 mm (1.25”) diameter paper former wound with a single layer of edgewound copper wire. More information is available by clicking here. All this and much more, not to be missed in Voice Coil February 2019. This edition is available for download and already in the mail for print subscribers. Subscribers can go to - www.gotomyvcoil.com - to download this issue.
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