Getting ready for another edition of the 2016 CES show in Las Vegas, NV, (January 6–9, 2016), in this month’s Industry News & Developments, Vance Dickason highlights what to expect from this gigantic event and details the many loudspeaker manufacturers attending.Since Voice Coil magazine celebrated the publication’s 29th anniversary in its November 2015 issue, this month Vance Dickason discusses the Test Bench column’s history and how it has evolved. In “Characterizing Drivers: Voice Coil Magazine’s Test Bench Process,” Vance outlines the Test Bench measurement protocol in detail, describing how his popular column does a complete objective analysis of a transducer in such a way that a speaker engineer or a DIY enthusiast can determine an appropriate application for the device. This includes a description on how Vance explored all the available acoustic analysis solutions from LinearX, DRA Labs, ACO Pacific, Audiomatica, Klippel, and Listen, throughout the years, taking as many measurements as necessary to accomplish the task.
One of our Spolight articles continues to discuss MEMS Microphones. In this issue, Mike Klasco (Menlo Scientific) discusses how VocalZoom’s Laser Microphone is able to differentiate a speaker’s voice from extraneous background noise. The VocalZoom sensor can be simultaneously used as a biometric sensor and a 3-D imaging sensor.
The December issue also includes an updated directory of Microphone Capsule suppliers, featuring a dozen of diverse but representative key mic capsule vendors, including those supplying low noise, matched mic arrays that are waterproof or have other value-added characteristics.
In Acoustic Patents, James Croft (Croft Acoustical) reviews the “Extended Duct with Damping for Improved Speaker Performance” recently granted to Apple, Inc. The patent describes an electronic audio device including an enclosure having an acoustic output opening and a speaker positioned within the enclosure, as implemented in the company’s range of iMac desktop computers, for instance. The speaker and the acoustic output opening are acoustically coupled by an acoustic output pathway. The acoustic output pathway includes a damping chamber to dampen a resonance frequency of the acoustic output pathway. The speaker is between the damping chamber and the acoustic output opening. As James points out, this type of structure was applied to television sets in the 1980s and 1990s by Mitsubishi and Matsushita, and disclosed in numerous patents. Apple’s patent cites the Matsushita patent as prior art, but this is clearly a more developed concept.
In this month’s Test Bench, Vance puts two pro sound drivers to the test. The first is the CF0617M, a new high power handling 6.5” midrange, from Celestion. The second is from Eighteen Sound, which sent a rather unusual driver because it is specifically intended for use with the new generation of Class-D digital amplifiers that can drive extremely low impedance loads. While Eighteen Sound has several models in this configuration, this test focuses on the 18” model, the 18iD.
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