In this issue of Voice Coil, Vance Dickason continues his exploration of available Outboard DSP systems. This month it's time for Marani Pro Audio and its MIR4801 Audio System Processor. Better known in professional audio circles, Marani offers an entire line of DSP processors used by many live sound manufacturers. Founded in Italy but now operating from China, Marani supplied DSP processing boards for amplifier modules, such as those from Danish company Pascal (which now sells finished products under the brand Blaze).The four inputs and eight outputs Marani MIR4801 is the second outboard DSP unit to be examined in this series of articles and is the company's flagship DSP processor. MIR stands for Marani Impulse Response, which refers to the proprietary Marani linear (zero) phase Linkwitz-Riley filter, which is described in a whitepaper titled "MIR a New Technology for Crossover Filters" by Michael Marani and Simone Castrucci, both from SEED Electronics, Guangzhou, China.
This issue of Voice Coil also includes the fifth article by Claus Futtrup in his series about the invention, concept, and historical perspective of loudspeaker bass reflex alignments. Starting in May 2024 with “Computation of Bass Reflex Alignments," the series expanded with classical alignments such as the B4, the LR4, the IB4, and most recently, the CD4 vented alignment, in the August 2024 issue. This Voice Coil Focus article explores the concept of transitional alignments, which is helpful in bridging between filter types. In the example detailed this month, Futtrup presents a transitional alignment between Butterworth B4 and Linkwitz-Riley LR4.
Next, Mike Klasco writes about "Developments and Materials for Enclosures and Consumer Audio Products." In line with the enclosures topic scheduled, this article explores plastics and composite materials along with some unique surface finishes, coatings, and fillings that enhance product characteristics. While wood and wood particle board cabinets have been traditionally used for speaker enclosures, there are now many material options for cabinets, depending on the intended applications, market segment and quality of finishing. With an article full of valuable knowledge and tips, particularly regarding fabrication stages, this month, Mike Klasco details new materials with an established supply chain, that support Design to Manufacturing, and sustainability options.
For this Voice Coil September 2024 issue, Vance Dickason characterizes two recent drivers with cutting-edge features from two leading manufacturers in different application segments.
First in Test Bench is the B&C Speakers DE640-16 Compression Driver, a 1.4" exit design, which along with the recent DCM414 midrange and the DE360 models represent a line of two-point suspension ring radiator type compression diaphragms. As Vance Dickason reminds us, the advantages of the two-point ring radiator were already recognized and explored in the very unique Advent hifi speaker designed by Henry Kloss and introduced in 1970. But this is a pro audio-oriented compression driver with a whole new level of performance for sound reinforcement.
The B&C Speakers DE640-16 features a 65mm (2.6") Polymer diaphragm driven by a voice coil wound with CCAW on a Kapton former, driven by a neodymium ring magnet. With a recommended crossover frequency of around 1kHz, and a 140W continuous power rating, the DE640-16 compression driver is well suited for applications such as stage monitors and PA speakers. For this Test Bench, the DE640-16 was matched with the Eighteen Sound XT1464 elliptical flare horn.
The second driver in Test Bench is the latest MR13TX-4 midrange from SB Acoustics - and more precisely, its fast-growing Satori line of high-end TPCD TeXtreme transducers. A dedicated 5" midrange driver, the MR13TX-4 is the 10th TPCD diaphragm transducer to be featured in Test Bench, which already characterized all SB Acoustics' TPCD TeXtreme tweeters, and woofers, apart from TPCD-based products launched by Eminence, SEAS, and more recently Scan-Speak - these last two brands already offering the latest metamodel TPCD technology from Composite Sound.
In terms of features, the Satori Textreme MR13TX-4 5" midrange is built on a proprietary two-piece cast-aluminum frame, comprised of narrow spokes, completely open below the BIMAX spider for cooling. The cone assembly consists of a curvilinear inverted single piece "bowl" shaped TeXtreme cone and an inverted NBR surround. Driving the cone assembly is a 1.2" diameter voice coil wound with round CCAW on a nonconducting fiberglass former and a neodymium motor.
In this month's Industry Watch, readers will find references to MISCO's 75th anniversary, CEDIA Expo 2024 and other audio industry events, leading up to new ALTI Audio Summit, which will take place in Scottsdale, AZ, March 5–7, 2025. This new initiative by Audio & Loudspeaker Technologies International (ALTI) will allow loudspeaker and related audio manufacturers from around the world to discover new technologies, identify new suppliers, and meet new business opportunities, within a world-class technical and business conference environment with great networking and social opportunities for all participants.
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