The October 2021 edition of Voice Coil is now available and opens with an overview of Industry News & Developments, with Vance Dickason discussing the latest Klippel Analyzer Time Frequency Analysis (TFA) software module, and the new range of coaxial speaker driver designs from Lavoce Italiana.
This month's Voice Coil Focus was written by Mike Klasco (Menlo Scientific) and Salvador Magdaleno-Adame (Salvador Consultant) and discusses "The State of Loudspeaker Magnetics." In this annual overview of a critical industry component for loudspeakers, Voice Coil offers valuable insights for manufacturers and product designers to better understand the pricing fluctuations, reliability, and volatility of supply chains, and general usage trends of the different magnet choices.
This portrait of the loudspeaker magnetics industry, discusses the evolution from Aluminum-Nickel-Cobalt (AlNiCo) alloy permanent magnets to ferrite and neodymium magnets and how drivers have been forced to evolve and adapt due to availability, prices of raw materials, and suppliers. Moreover, the article explores the strategical importance of rare material supply, geographical and geopolitical implications, and mitigation strategies, which include the increasing use of recycled materials. Being a very small fraction of the overall magnets industry, audio products will increasingly be a great first-line candidate for recycled magnet production.
This edition also follows up on an article about active, portable, and smart speakers published in the September edition of Voice Coil, with an industry directory focused on Integrated Electronics. The directory, compiled by Mike Klasco and Nora Wong, lists major OEM, ODM, and contract manufacturing and system suppliers for soundbars, smart speakers, powered speakers, and DSP modules and algorithm suppliers. It also includes a brief directory of manufacturers of amplification modules, DSP modules, and power supplies for active designs.
For this month's Acoustic Patents column, James Croft (Croft Acoustical) discusses an interesting patent that was recently granted, concerning a design by Coastal Source of a product that was highlighted at the CEDIA and InfoComm shows a few years ago. Titled simply "Audio Speaker," US patent 11044540 was submitted at the end of 2019, with Franco L. D’Ascanio, Franco C. D’Ascanio, and Sean P. Snowden listed as inventors, all working on behalf of the Florida-based outdoor audio and outdoor lighting specialist.
The patent in question, applies to the design of Coastal Source's Line Source Bollards, an unusual outdoor audio "high-end" speaker, that is capable of impressive performance over massive listening areas, thanks to the ingenious use of a ribbon line array arrangement (using Radian Audio ribbon-planar drivers) matched to a patented variable waveguide design that aims to generate constant coverage of near-field, mid-field, and far-field listening areas. Described as a "variable waveguide speaker control" solution, this design uses a unique laminar flow grill design, consisting of a multi-layer sandwich arrangement that also protects the speaker components from performance damage UV rays, dust, debris, water, and ice. A design that James Croft finds to be a laudable and valuable invention.
For this month's first Test Bench explication, Vance Dickason characterizes the 15DS100 15” professional subwoofer from B&C Speakers. This new transducer from the Italian company is a very high power handling design, able to deliver 3kW continuous (1.6W nominal), thanks to B&C's latest generation of very long voice coils - a great asset in applications from discreet PA subwoofers to three-way PA speakers. The B&C 15DS100-4 uses a proprietary 12-spoke (six twin spokes) cast aluminum frame with cooling vents for the neodymium motor assembly, and a cone assembly consisting of a ribbed flat profile paper cone with a waterproof coating on both sides and dust cap. Compliance is supplied by a three-roll pleated coated cloth surround, and a double silicone 6” diameter flat spider. Tinsel leads are stitched into the spider for long-term stability. The FEA motor design on the 15DS100 woofer uses a 100mm (4”) diameter four-layer voice coil wound with round aluminum wire on a non-conducting glass fiber former, and feature an aluminum demodulation ring.
The second Test Bench focuses on Eighteen Sound’s latest ND2T, a 1.4” neodymium compression driver, combined for characterization with the XT1464 elliptical-shaped horn, also from Eighteen Sound. This ultra-compact compression driver features a 61mm (2.4”) diameter edge-wound voice coil wound with aluminum wire on a non-conducting Nomex former with a proprietary treatment that shows a 30% higher value of tensile elongation at operating temperatures (200°C) when compared to Kapton. This assembly drives a field-replaceable pure titanium diaphragm. The ND2T also incorporates a proprietary tangerine radial phase plug design. Other features include a computer-optimized neodymium ring magnet motor structure, copper pole piece shorting ring, a continuous power handling of 160W with a 80W nominal power handling rating, a 1.2kHz recommended crossover frequency (with a minimum 12dB/octave high-pass network), corrosion-resistant coating on the magnets and plates, black emissive coating on the rear cover, and a 2.83V/1m 110.0dB sensitivity, plus standard solderable terminals.
This edition also offers the mandatory dose of Industry Watch stories, highlighting updates to LoudSoft's latest version of its box design software, FINEBox 2021, a new analyzer and DSP filter generator from Brazilian company F.MonteiroScience, and the latest updates on trade show cancellations.
The October 2021 edition 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: audioxpress.com/page/Voice-Coil-Subscriber-Services.html
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