I frequently learn about new products from brands large and small, which sometimes remain unnoticed for multiple reasons (and I don't mean by the press) regardless of how innovative they are. That's a topic in itself to be addressed in a separate editorial one of these days... This week, I spent some time looking at a few speakers that I think deserve a spotlight. Please note that I have not heard those speakers. I just think they are interesting products that deserve a mention.

The first example is a new speaker that I learned about from a recent patent review that James Croft wrote for Voice Coil magazine’s February 2021 edition. This new speaker is from an obviously Dutch company from Rotterdam, named Dutch & Dutch. As Croft noted in his patent review, apparently their research shares the same engineering fundamentals and goals applied in another remarkable product with roots in The Netherlands (and Germany), Kii Audio's Three.

As audioXpress could demonstrate in its detailed review among their many innovations, the Kii Three speakers achieve extremely well-controlled directivity in the lowest frequencies. In our extensive 2017 review, audioXpress even measured the speakers directivity pattern at 100Hz, showing it to be an almost perfectly cardioid.

The Dutch & Dutch patented design used in its 8c speakers - the company's first and so far only product - also achieves directivity control all the way down to 100Hz. On its website, D&D mentions constant directivity with a "+/-0.5dB frequency response from 35Hz upward." The 8cs combine a proprietary waveguide tweeter with an acoustic cardioid midrange, rear-firing boundary-coupled bass drivers and DSP-controlled active room matching, allowing the speakers to be placed close to room boundaries. To achieve its cardioid response on the midrange, Dutch & Dutch designed two openings on the enclosure's side panels, introducing a phase delay that causes an effective attenuation (15dB or more) of the midrange frequencies.

Brian Lowe (Belleson LLC) continues his search for the Unicorn in the second (and final) part of his article, this time focusing on the test fixtures. Testing a voltage regulator with exceptionally good performance requires an even more exceptional signal source and measurement setup to measure sub-microVolt ripple across a wide frequency range. Complementing the final article - a must-read for anyone into audio electronics - Jan Didden, audioXpress' technical editor, offers an informative sidebar about super regulators to enhance the information provided by Brian Lowe in his main feature article. This article was originally published in audioXpress, June 2019.  Read the Full Article Now Available Here

Every month on his Voice Coil magazine Acoustic Patents column, James Croft (Croft Acoustical) discusses different loudspeaker patents and inventions that are relevant to the audio industry. For this specific article, he reviewed two loudspeaker-related patents as a tribute to David John Graebener, who passed away on January 3, 2015. First James Croft reviews the planar-magnetic electro-acoustic transducer he patented together with Graebener, followed by a single-end planar magnetic speaker system, Graebener’s key patent. These were the first and second of the Single-Ended, Neodymium planar magnetic transducer patents David Graebener was granted, which were followed by six other patents all related to planar-magnetic speaker designs. This article was originally published in Voice Coil, March 2015.  Read the Full Article Now Available Here