Errata, Corrections, & Updates

Our editorial staff endeavors to publish accurate information in audioXpress magazine, Voice Coil magazine, The Loudspeaker Industry Sourcebook, and The World Tube Directory. When necessary, the staff will post notes pertaining to errata, corrections, and updates on this page. Please send your comments and suggestions to


Voice Coil January 2014

Celestion was incorrectly identified in the January issue of Voice Coil. Celestion is a UK-based company.


Voice Coil August 2013

The directory of OEM Voice Coil suppliers Voice Coil’s August issue (p.14) included incorrect information. Chen Hong Industrial does not supply voice coils to Italian pro sound driver manufacturer RCF. RCF has never done business with Chen Hong Industrial. Our apologies to RCF!


audioXpress July 2013

Figure 2 and Figure 3 published on p. 37 of Vance Dickason’s Test Bench column (audioXpress July 2013) were incorrect. The two figures, part of his review of the Beston Technology RT004A ribbon tweeter, appear correctly below.

Beston RT004A on-axis frequency response









Figure 3: Beston RT004A on- and off-axis horizontal frequency response (0° = solid black; 15° = dot blue; 30° = dash green; 45° = dash/dot purple)




audioXpress June 2013

An incorrect biography for audioXpress contributor Ron Tipton was published on p. 44 of the June 2013 issue. His correct biography appears here:

Ron Tipton has degrees in electrical engineering from New Mexico State University and is retired from an engineering position at White Sands Missile Range. In 1957 he started Testronic Development Laboratory (now TDL Technology, Inc.) to develop audio electronics. During the 1960s and 70s, TDL built active filters and pseudo-random noise generators for well known companies such as Bose Corp. and Acoustic Research. He also designed several audio products for GMS, Inc., a contractor to the Baldwin Piano and Organ Co. He is still the TDL president and principal designer.


Voice Coil March 2013

In Voice Coil’s Test Bench section (p. 20), the review on Tang Band’s T1-1942S incorrectly listed the company’s website. The correct website is


audioXpress May 2013

In Bruce Heran’s article titled “Poddwatt Series II Stereo Integrated Valve Amplifier,”  published in the May 2013 issue of audioXpress, an error appears in the main schematic on Page 18. Here is the corrected schematic.


Loudspeaker Industry Sourcebook 2012

  • Applications Acoustiques de Composites (AAC) was inadvertently not included in the 2012 Loudspeaker Industry Sourcebook’s “Loudspeaker Cone Vendor Survey 2012” article. AAC is a major cone manufacturer. Created in 1989 from the NEOS Company founded in 1935, AAC has become a major manufacturer of loudspeaker components.

In addition to manufacturing membranes in cellulose fiber (paper), AAC has become more diversified through the development of new technologies and the use of materials such as glass fiber, aramid fiber (Kevlar), carbon fiber, titanium, aluminum, ceramics, plastic materials and, more recently, magnesium or sandwich composite.

With customers worldwide, AAC produces cones and membranes, domes, dust caps and dust barriers, surrounds, and spiders. AAC also manufactures domes for tweeters, notably the automobile industry. To contact AAC, visit; AAC, ZI Chemin de la Poterie, 72340 La Chartre Sur Le Loir, France; call +33 (0)2 43 79 03 60; or e-mail

  • The 2012 Loudspeaker Industry Sourcebook also incorrectly identified Audax, which is a drivers manufacturer. To contact Audax visit;  ZI Chemin de la Poterie, 72340 La Chartre Sur Le Loir, France; call +33 (0)2 43 79 03 60; or e-mail


audioXpress February 2013

  • A review of the Motus UH25CTi dome tweeter, from Motus Audio, starts on page 38 of the February 2013 edition of audioXpress. The table of contents on page 4 includes an incorrect reference to the page number.


Voice Coil October 2012

  • On page 5 in the Supporting Companies section, the correct URL for Eckel Industries, Inc. is
  • For NTi Audio on page 28 in the Measurement Microphone Sourcebook Directory section, Tom Mintner is the sales contact for NTi Americas. The other listed name was an error.