Patent Review: Head-Related Transfer Function Equalization and Transducer Aiming of Stereo Dimensional Array (SDA) Loudspeakers

This patent, awarded to Polk Audio, describes a very specific loudspeaker design that claims to be able to achieve better stereo sound reproduction with “a realistic ambient field and a larger, and more stable acoustic image.” This obviously aims at achieving something that Polk Audio actually patented nearly 40 years ago, with its original Stereo Dimensional Array (SDA) loudspeaker, and for which the new updated patent now provides a new improved version. This article was originally published in Voice Coil, February 2019.

Longtime audioXpress contributor Gary Galo writes about a transformer-coupled balanced output circuit for solid-state preamps, usable with line-level signals. Exploring the differences between balanced interfaces and unbalanced interfaces - and finding things that we really want to be aware of, he then explains why he selected Jensen transformers for his own project. This article was originally published in AudioXpress, February 2019.

In this review for audioXpress Stuart Yaniger puts 1MORE’s Triple Driver Over Ear headphones through a series of rigorous tests. Intrigued by the design that uses a 40 mm graphene-coated dynamic driver, a ceramic tweeter, and what the company calls a bass reflector, Stuart Yaniger investigated and shares his findings. This article was originally published in audioXpress, February 2019.

For this Test Bench, Vance Dickason actually had lots of fun characterizing a new version of a legendary 6.5” woofer recently announced by MISCO (Minneapolis Speaker Company). The new MS-10W, will be marketed under the new MISCO brand, Bold North Audio, and it is effectively a direct replacement for the famous white driver on Yamaha’s NS10 studio monitors! This article was originally published in Voice Coil, February 2019.

Always exploring all the latest information regarding cone and diaphragm technology, Voice Coil regularly publishes reports on key new materials with the potential to excite the loudspeaker industry. In this special focus article, Mike Klasco (Menlo Scientific, Ltd.) explores new approaches that explore thin ply carbon materials, like Swedish advanced composite specialist Oxeon is attempting with its TeXtreme Thin Ply Carbon Technology. This article was originally published in Voice Coil, February 2019.

Our longtime columnist Richard Honeycutt shares his insights on Geoff Hill’s recently released book, Loudspeaker Modelling and Design: A Practical Introduction, which demonstrates modern software and hardware being applied to the processes behind loudspeaker design and modeling. Learn more about this indispensable work, now available from publisher Routledge / Focal Press. This article was originally published in audioxpress, February 2019.

Voice Coil February 2019 is now available and features a Cone and Diaphragm Technology Focus, including an expanded directory of Loudspeaker Cone Industry Suppliers, and an updated directory of Headphone/Earphone Parts vendors - the first of its kind. In Acoustic Patents, James Croft discusses a new patent awarded to Polk Audio, updating the original Stereo Dimensional Array (SDA) loudspeaker with a new improved crosstalk cancellation version, and Vance Dickason characterizes the new Bold North Audio MS-10W woofer, a direct replacement for the famous white 6.5” driver on Yamaha’s NS10 studio monitors!

audioXpress February 2019 is now available online and in the mail to all subscribers and will be distributed at the Winter NAMM show 2019 in Anaheim, CA. And to match the exciting environment, we reviewed the new d:vote 4099 CORE Instrument Microphone from DPA Microphones, visit Pascal to learn more about its pro audio amplifier modules, explore transformer-coupled balanced output circuits, and much more. There's even a DIY project for a disc recording stereo head. Really. A must read!