Electrostatic Loudspeakers and Two Cutting-Edge High-End Tweeters in Voice Coil June 2023

Voice Coil June 2023 features an extensive patent review in James Croft's Acoustic Patents column. The topic is a 2014 patent awarded to Nokia, offering an opportunity to revisit the history of electrostatic loudspeakers, with insights from Tim Mellow, one of the two listed inventors. In Test Bench, Vance Dickason focuses on the D8404-552000 Ellipticor cloth diaphragm dome midrange from Scan-Speak, and characterizes the SB Acoustics TW29BNWG beryllium dome and waveguide from the brand's prestigious Satori line.

GRAS Sound & Vibration, now part of Axiometrix Solutions, has confirmed that all its ear simulator test platforms now include Transducer Electronic Data Sheet (TEDS) calibration functionality. GRAS, together with sister company Audio Precision, has long focused on incorporating TEDS in all systems to ensure reliable data and to ease all aspects of installation and test platform setup.

GRAS Sound & Vibration announced that its line of production line tools for high-frequency measurements now includes the only 0.4cc couplers that follow the most recent IEC standards, offering a cost-efficient validation tool in the frequency range up to 16 kHz that adheres to standards. The latest IEC standard 60318-8:2022 describes an acoustic coupler for loading a hearing aid or insert earphone with a specified acoustic impedance when testing its acoustic performance, in the frequency range up to 16 kHz.

Bruel & Kjaer has a new miniature microphone ideal for high-precision acoustic measurements tests within confined spaces – Type 4988-A. A mini, yet mighty microphone, this new 1/4" low noise, prepolarized, all titanium microphone was designed to help engineers and acousticians achieve accurate measurements in everyday tasks. The new Type 4988-A is flat from 20Hz to 20KHz (±1 dB) and can be used close to hard reflective surfaces, or very close to sound ports of an audio device.