You Can DIY! Egg Speaker Amp and System

Most of our readers still remember Tom Perazella’s extraordinary egg speaker project with SB Acoustics Satori drivers, featured in the September, October, and November 2018 issues of audioXpress. Inspired by that design, Metz decided to build his own version, and also explore his own take with an active crossover tri-amp approach using a miniDSP 4x10HD system feeding a dedicated six-channel amplifier using Purifi 425W Class-D units. The new Egg Speaker Amp and System is an inspired take on the original. This article was originally published in audioXpress, July 2022.

The Chief Science Officer at AudioTelligence discusses the merits and challenges of using beamforming and blind source separation techniques to correctly process voice sources from the audio signals picked up by microphones in real-world situations. This article explains how these signal processing techniques can help deal with the noises that make it difficult to pick out and clearly hear voice, and how to obtain clean audio signals picked up by microphones contaminated with interference, noise, and reverberation. This article was originally published in audioXpress, November 2022.

This SEAS Excel Midwoofer is one the most highly inventive and innovative out-of-box Hexadym Motor designs from the Norwegian company. In this article, Vance Dickason details all that is unique in this midwoofer design and its historical motivations, helping to solve the problem of reflections off the motor system and frame of a woofer back into the cone. A fascinating exploration with complete measurements. This article was originally published in Voice Coil, July 2022.

This Test Bench characterizes a 15" Ellipticor woofer from Scan-Speak using the company's proven oval/elliptical design topology. The 38WE is a seriously feature rich transducer, starting with a nicely configured 10-spoke cast-aluminum frame and a completely open area below the suspended spider mounting shelf for effective cooling of the Symmetrical Drive (SD) AirCirc multi-magnet design with neodymium slugs and elliptical two-layer voice coil. This article was originally published in Voice Coil, July 2022.

James Croft explores patents granted to Mattias and Timothy Scheek, on behalf of Mayht Holding B.V. Our readers will recognize the name from the April 2022 announcement of the acquisition by Sonos of Mayht Holding BV, for "$100 million in existing cash on hand.” Having followed their work through a number of patent publications, Mayht's technology triggered Croft's curiosity, for its unconventional structural designs, appearing to represent fresh thinking. This article was originally published in Voice Coil, July 2022.

The three previous articles described circuits that Ethan Winer developed for his current project that uses an electric guitar instead of a keyboard to control an analog synthesizer. This article continues with two pieces needed to process input from an electric guitar: the input section’s preamplifier and noise gate, and the pick detector. The preamp amplifies the weak signal from an electric guitar’s pickup and brings it up to line level for further processing. The noise gate detects when a note is currently playing and when it stops. Of course, the pick detector signals each time a new note is picked.

This article provides a valuable overview of the latest Thin-Film Coatings and Treatments solutions that are available in the market. Highlights include a new a state-of-the-art REACH-compliant CVD coating process from Oerlikon Surface Solutions, applicable on multiple substrates, such as aluminum, titanium, PEEK, and composites, and Nanovate, a metallurgical nano-coating technology based on electrodeposited nano crystalline structural metal from Integra. The report also highlights Antiviral/Antimicrobial Coatings from Integran, Kastus Technologies, and Nanowatt, among others. This article was originally published in Voice Coil, July 2022.

As the audio industry gradually resumed its trade show calendar in result of the global pandemic, Oliver A. Masciarotte offers a report from the 2022 edition of Audio Expo North America, better known as AXPONA - the most important annual hi-fi and high-end audio show in the US. As audio enthusiasts and audiophiles returned once again to listening in person at the Renaissance Schaumburg Convention Center Hotel, there was a lot to explore in very little time. This article was originally published in audioXpress, July 2022.

The July 2022 issue of Voice Coil offers important resources for the industry with a focus on Adhesives, Coatings and Treatments. Mike Klasco writes about New Thin-Film Technologies for Coatings and Treatments. James Croft returns with a fresh review of a Mayht patent. And Vance Dickason characterizes the recent 38WE/8582T00 15” Ellipticor woofer from Scan-Speak, and explores the historical relevance of the SEAS W15CH001 5.25" Excel Midwoofer and its Hexadym Motor design.

Read audioXpress July 2022 to learn the latest about Audio Amplification technology, an interesting perspective on audio bandwidth measurements, and read the AXPONA 2022 report. On DIY audio, this issue offers a solid-state, modular preamplifier project by Bruce Heran, the Egg Speaker Amp and System by Reinhardt Metz, and how to achieve a triode sound by Richard Honeycutt. And Ethan Winer describes the input stages for his Guitar-Controlled Synthesizer project.