Test Bench: The New 7.5” MT19CP-8 Coincident Coaxial Driver from the SB Acoustics Satori Line

The new 7.5" coaxial driver from SB Acoustics' prestigious Satori line is built on a rather stylish aluminum-cast frame, totally open below the spider, with a cone featuring SB's proprietary Egyptian Papyrus material with a three-roll coated cloth-type surround, driven with a 1.52" diameter voice coil and neodymium magnet. The 1" tweeter is comprised of a coated cloth-type dome diaphragm, powered by a neodymium motor, which incorporates a resonant back chamber design.

Even a perfectly linear loudspeaker produces two types of distortions because of the movement of its membrane. First Doppler distortions, a.k.a. Phase Modulation (which the author addressed in his October 2024 article for audioXpress), and secondly distortions stemming from the Nonlinear Amplitude Modulation, characterized in this article. More importantly, this article also addresses how these harmonic and intermodulation spectral line distortions can be minimized and eliminated in loudspeakers.

This article, written by Anthony Caiazzo, Chief Technology Officer and Principal of Countervail Products, details the company’s family of vibration canceling materials featuring a patented approach that has been shown to provide exceptional levels of vibration damping in many common structural configurations. Countervail materials not only cancel vibrations, but they also contribute to the stiffness of the structure and typically don't significantly change the component manufacturing process.

This article describes how Audioscenic's Amphi Technology effectively enables an evolution in 3D sound and immersive reproduction through loudspeakers. Audioscenic developed a sound reproduction technology that allows for the real-time adjustment of spatial audio systems, providing an effective and natural ability to hear in three dimensions without the need for the listener to be constrained within a specific sweet spot.

This article is a detailed review of the intriguing AVAA C214 Digital Active Bass Absorber from Swiss studio monitor and high-end speaker specialist PSI Audio. The concept is more or less the same as the AVAA C20, which PSI launched in 2017. the first commercially available analog active bass trap. Now, with the AVAA C214, PSI has introduced a digital controlled active bass trap that's better suited to deal with room modes below 150Hz in listening spaces and small studios rooms. For this review, the solution was tried and tested in two different spaces and applications.

A fascinating conversation with Andreas Ehret, Senior Director, Automotive at Dolby Laboratories, recapping his career and personal journey prior to and with Dolby, through truly pivotal moments in audio history. In this exchange we learn how Dolby Atmos evolved from the ultimate movie soundtrack format into the heart of consumer experience - for the very first time successfully challenging stereo reproduction. And how Dolby evolved its business model to become today's indispensable technology partner to both the media and the automotive industry.

In Voice Coil November 2024, Anthony Caiazzo details Countervail's patented fiber-reinforced composite technology, Mike Klasco revisits solutions to achieve increased bass response, while James Croft reviews two patents from Clean Energy Labs and Brane Audio that seem to have finally broken Hofmann's Iron Law. In Test Bench, Vance Dickason characterizes the new MT19CP-8 7.5" coaxial driver from SB Acoustics' prestigious Satori line.

This November 2024 issue of audioXpress explores perspectives on signal processing, and sound reproduction. Read a review of the PSI Audio AVAA C214 digital active bass absorber, learn about the exciting possibilities of Audioscenic's Amphi Technology and how to explore the Boundaries of Active Noise Cancellation. J. Martins interviews Andreas Ehret from Dolby Laboratories. Expanding on speakers, we explore Field Coil speaker drivers, Non-Linear Amplitude Modulation distortion and more.