Get in the Loudspeaker Industry Loop with Voice Coil July 2017

June 26 2017, 09:00
This month, in Industry News and Developments, Vance Dickason highlights the first two models in the new Scan-Speak Ellipticor driver range, which combines a series of design innovations (e.g., elliptical voice coils) resulting in lower distortion, combined with higher SPL. We also discuss the new FEA18RCZ Prestige full range 6.5” driver, from Norwegian speaker designer and manufacturer SEAS Fabrikker.
Next, we have an enlightening article By Dan Knighten (Applications Engineer, Listen, Inc.) about “Practical Measurement of Bluetooth and Lightning Headphones.” In this Spotlight article, Knighten provides valuable perspectives on how to deal with the challenges of measuring devices that connect directly to Apple’s Lightning port or USB-C, or work wirelessly, using Bluetooth. In all cases, these headphones present unique challenges to measurement because they cannot be directly connected to traditional test and measurement systems. The article describes how to use “open loop” measurement approaches, where there isn't a continuous or synchronous signal chain, and still measure all relevant parameters of a device.
Voice Coil then focuses on the Acoustical Characteristics of Adhesive Joints and Cone Treatments, in a special report prepared by Mike Klasco and Steve Tatarunis (Menlo Scientific). This article details how the influence and use of glue joints and diaphragm treatments can be used as a design tool. The report also details the latest significant new material options and design and measurement tools available.
Complementing this month’s Focus, Nora Wong (Menlo Scientific) prepared an updated directory of “Adhesives, Coatings, and Sealant Providers for the Speaker Industry.” A valuable resource.
On Acoustic Patents, James Croft (Croft Acoustical) examines an important patent filed in 2014 by F. Bruce Thigpen (Tallahassee, FL) and granted in June 2016. Appearing both as the inventor and assignee, Thigpen describes a rotary sound transducer having an improved output at higher frequencies. As the patent abstract details, “The invention includes stiff vanes that are preferably rigidly attached to a hub. A torsional actuator is provided in each vane. The torsional actuator selectively twists the tip portion of each vane. The torsional actuator for each vane is activated by an input energy source corresponding to the sound waves that are desired. The input force may also be electromechanical energy, purely mechanical energy, or some other form of energy.”
For this month’s Test Bench, Dickason characterizes the new DE990TN 1.4” throat compression driver from Italian Pro Sound OEM manufacturer, B&C Speakers. The DE990TN is the “little brother” to the titanium diaphragm DE1090TN compression driver, which was featured in the August 2016 issue of Voice Coil. As with the DE1090TN, the DE990TN was coupled with B&C Speakers’ ME90 80° × 60° constant directivity horn. 
Dickason also looks in detail at Wavecor’s new SW168WA01 6.5” woofer. Another model from the brand's extensive subwoofer line, Wavecor’s SW168WA01, available only as a 4 Ω model, has a generous feature set, resulting in largely reduced even order harmonic distortion, and low distortion even at high output levels.
All this and much more from our monthly Industry Watch updates, which also detail what the Association of Loudspeaker Manufacturing and Acoustics (ALMA) International is planning for its forthcoming ALMA International Symposium & Expo (AISE) 2018, now taking place in a new venue, the South Point Hotel and Casino in Las Vegas, NV.
Voice Coil July 2017 is now available on print and download for all registered subscribers. If you already subscribe, just go to - - to download it. Remember, Voice Coil is free for industry professionals. To qualify for a free subscription to Voice Coil, or renew your subscription, just go here:
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