Fasten Your Seatbelts. Knowledge for Speaker Designers Now Available in Voice Coil September 2025

In this issue of Voice Coil, you can’t miss Mike Klasco’s history lessons and situation report on speaker magnets and rare earth materials, his updated Directory of Materials Manufacturers for Consumer Audio Products, and subdirectory on Transducers for Soundbars and Bluetooth Speakers. Vance Dickason’s Test Bench characterizes the new BGW-D182-86-4-001 glass cone woofer from Glass Acoustic Innovations Technology (GAIT), followed by the W 174.38 Fibonacci woofer from RS Speakers, both being 6.5” drivers with innovative approaches.

When Sony introduced its new flagship Signature Series MDR-Z1R headphones, it received mixed reviews from precisely the user communities that it targeted, considering its hefty price tag that placed it in direct competition with Audeze, MRSpeakers, HiFiMan or Stax. Already announced in Asia and more recently at IFA in Europe, the new Sony MDR-Z7M2 premium headphones inherited core technology from the MDR-Z1R, uses new 70mm drivers, keeps the comfortable design, and retails at a much more affordable price.

Fibona Acoustics, founded in 2015 and headquartered in Copenhagen, Denmark, has introduced a new patented driver technology Enclosure Magnet Coaxial Transducer (EMCT), developed by Milad Kahfizadeh, an industry veteran and the company's founder. The design has a shallow coaxial design of the diaphragm, a self-containing enclosure, and high sensitivity, with improved high frequency sound dispersion.