R&D Stories: Design and Development of the Holoplot X1 Matrix Array

Many product designers and manufacturers in the audio industry the world over have been making huge leaps forward in hardware, software, and interoperability that they have been largely unable to show off thanks to a disruption to live events. Following the return of trade shows in 2022, the lid has been lifted on a whole host of innovations in the pro audio space, and among them Holoplot has emerged as a standout with its X1 Matrix Array sound system. This is an inside account about how the Holoplot team has been pushing the boundaries of what is possible in the pro audio space.

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.

Renowned tube expert Michael Boele offers his long-term review of a pair of 2021 new production 300B directly heated power triodes. For 10 months, Boele had the opportunity to live with and extensively use a pair of these 300Bs and his impressions and extensive testing could be directly contrasted with his considerable collection of 300B tubes - Chinese, Russian, Czech and Slovak clones, as well as several pairs of Westrex/Western Electric reissues, and two “old stock” Western Electrics. This article was originally published in audioXpress, May 2022.

Expanding on previous articles about bass shakers and motion platforms, this article from Mike Klasco (Menlo Scientific) looks at exciting evolutions in haptic transducers and actuators that are being used in a growing number of applications - all of which depend upon audio sources for input. The ability to interact with the world through vibration and touch is central to all of our lives, and now increasingly so. This article was originally published in audioXpress, February 2022.

In this article, James Croft reviews a generic “Loudspeaker” concept patent, granted to Teppei Yamada, of Tokyo, Japan, on behalf of Zorzo Co., Ltd. and which describes a somewhat surprising concept of a loudspeaker that includes a hermetically sealed enclosure, with a driver outside of an enclosure and a second driver inside, with a pipe communicating between the two drivers. The second driver is configured to output a signal of opposite phase to that of the first driver. This article was originally published in Voice Coil, October 2016.

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.

In this article, James Croft looks at a patent awarded to David Russell (Toronto, CA); and John French (Caledon, East, CA) on behalf of Audera Acoustics, Inc., Schomberg CA. The patent describes a generic acoustic high displacement transducer system, containing a diaphragm position sensing module, a controller with a transmitter, so that the voice coil moves at least partially in response to the control signal.

This article reviews a patent originally granted to inventors Philip R. Clements; (Tempe, AZ), Boaz Shalev; (Needham, MA), and James Joseph Croft, III; (Bellevue, WA), which has now expired. The patent describes a low-frequency transducer system with a multi-compression chamber, where an inverse horn structure is employed in combination with a resonance-distortion filter chamber. This was the third patent granted on Atlantic Technology’s low frequency system known by the trademark name H-PAS (High Pressure Acceleration System). This article was originally published in Voice Coil, September 2016.

Exploring some pressing topics in headphone technology, in this article Hans W. Gierlich addresses the requirements for effective performance testing of communication headsets that use active noise cancellation (ANC) technologies, test setups, testing equipment, and setup conditions needed to correctly assess ANC performance. From the right choice of artificial ears and the latest ITU-T recommendations in that domain, to ANC performance measurements and talk-though performance. This article was originally published in audioXpress, June 2022.

This important article revisits the evolution of Rub & Buzz measurements in loudspeakers, headphone drivers, and microspeakers production lines, and how these are being addressed using the next-generation of perceptual algorithms. Steve Temme offers a valuable comparison with what can be accessed today using modern methods, and what to apply to access production faults, determine thresholds for production yields, or understand the real impact on consumer's perception. This article was originally published in audioXpress, April 2022.