Patent Review: Loudspeaker Having a Passive Radiator US9426548B2

This article discusses a very interesting design and patent granted in August 2015 to Gary A. Rayner and James C. Larsen, as the inventors, on behalf of Treefrong Developments, from San Diego, CA. The patent abstract details a loudspeaker using one or more active drivers, with a passive radiator connected to each driver and dedicated processors and amplifier per channel - a slightly different approach to a familiar concept. This article was originally published in Voice Coil, November 2015.

Stuart Yaniger continues to examine ways to create a low-cost system for lab-grade audio electronics measurements. In this article, a few measurement examples are used to illustrate the power and the versatility of sound-card-based measurements. To illustrate the usefulness of measurements in the design process, Yaniger also explores the effects of load on power supply noise for a common IC regulator circuit. This article was originally published in audioXpress, November 2015.

November 2015 marks the beginning of Voice Coil’s 29th year as an information resource for the loudspeaker industry. So there’s definitely reason to celebrate and several good reasons to download the issue right now. Including a MEMS Microphone Status Update, Measurement Microphone directory, and Test Bench, which focuses on the UH205PW1 8” mid-bass driver from Motus.

Do you want to know how good audio from smartphones actually is? Would you like to know which sound measurement apps are available for smartphones? Or would you prefer to build The PhaseBuster, a unique way to manipulate the phase between stereo channels? Or would you prefer to build a headphone hybrid amplifier? All that and much more can be found in audioXpress November 2015, available online.