R&D Stories: Acoustic Diffusion Research

This article offers a valuable inside perspective about developing new diffuser solutions, and lessons learned while designing countless critical listening rooms around the world. A journey that lead to the creation of the PolyFlex diffuser, which will scatter either horizontally or vertically, depending on the orientation, and improve clarity in speech and spatial focus without making a room sound dead and/or small. The author was actively involved in multiple acoustics standards committees, including for testing procedures.

The August 2022 issue of audioXpress, Acoustics Focus, gives a unique overview of market trends in acoustical products, with great articles on Acoustic Diffusion, Distributed Subwoofers for Room Modes, and Reverberation Control and Measurement. Michel Nieuwenhuizen proposes an improved microphone preamp for condenser microphones, Aren van Waarde builds a minimalist preamp using only discrete transistors, and Ethan Winer shares circuits for VCA and VCF analog synthesizer modules.

Following a first R&D article, where Norman Varney discusses the basic principles of unwanted vibrations in audio playback environments, in this second part he writes about what his research found to be effective ways to counteract those effects. The article details the evaluation process and extensive measurements that lead to the creation of various products that AV RoomService provides when helping clients with their acoustic problems. This article was originally published in audioXpress, September 2019.

In this article, Norman Varney discusses the basic principles of unwanted vibrations in audio playback environments. "When we play back audio, we only want to hear sound waves created from the electromechanical vibrations produced by the loudspeaker. They are the result and intention of the artists. They are the original signals. These are good vibrations. However, for this article, we will focus on the basic principles of unwanted vibrations of audio playback environments," states Varney in the article introduction, originally published in audioXpress, August 2019

The September edition of audioXpress is our always popular Speaker Builder - Speaker Focus edition. Once again, audioXpress focuses on loudspeaker building, design, and testing and for this issue we have combined two great DIY articles with a review of the PureAudioProject Trio15 Heil AMT speaker system. Ward Maas reports from the High End 2019 show in Munich, Jan Didden met with Purifi Audio's Bruno Putzeys and Lars Risbo and comments on the company's research, and much more.

The August 2019 edition of audioXpress features the latest Acoustical Solutions product round-up, and several contributed articles on acoustic-related topics, including, evaluating auditorium acoustics, measuring unwanted vibrations, and frequency timing. This edition also includes Stuart Yaniger's review of the Kali Audio LP-6 Powered Studio Monitors, Ken Bird's assembly-review of the Swans Speakers DIY Kits, and Oliver A. Masciarotte's report from AXPONA 2019. Now available for download and in print!