Design, Simulations, and Measurements in Voice Coil December 2024

In this December 2024 issue there's a new DSP product review of the Marani Pro Audio MIR260A outboard processor, and Lars Risbo shares his expertise in Numerical Optimization applied to Speaker Box Alignments. Essential resources are the updated directories of Test and Measurement and of Simulation and CAD Software vendors. On Test Bench, Vance Dickason characterizes the Faital Pro HF110 1" Neodymium Motor Compression Driver and the SB Acoustics Satori MR16TX-8 6.5" TPCD Midrange.

In this article Mike Klasco shares his extensive knowledge about voice coils, and how this critical part of loudspeaker technology has evolved - the result of decades of walking factory floors all over the world . As noted in his introduction, "Winding some wire into a coil should be simple enough and after a century of loudspeaker manufacturing, there shouldn’t be any new surprises. But voice coil materials, process control, and topology continue to evolve and here we discuss half a dozen noteworthy new tricks."

The Scan-Speak D3004/606200 is a 1" compact tweeter from its Illuminator Line, and features the new generation of Metamodal TPCD diaphragms. Scan-Speak has been participating in Composite Sound's metamodal development program, and the new D3404 tweeter is the first to be released. It features a low resonance, injection-molded rear chamber, SD-2 neodymium motor, large-roll coated cloth surround, and black anodized machined aluminum faceplate. This article was originally published in Voice Coil, July 2024.

This Test Bench characterizes the new Scan-Speak 15W/8534T00 woofer, which fills the gap in the Classic family for a compact high-performance 5.5” (15cm) midbass driver. It is based on the design principles of the popular 18W/8545 continuing the tradition with a slim frame aluminum chassis, Symmetrical Drive (SD) motor system, low loss linear rubber suspension, and updated with a brand-new cone material called Phenomax.

The 10PR330 is Faital Pro's new high-power handling 10" woofer intended for line arrays and large PA systems, or as a midbass driver in multiway systems — and apparently it has also been also used successfully in bass guitar applications. The cone assembly for the Faital Pro 10PR330 woofer consists of a curvilinear paper cone along with a very stiff coated dust cap. Compliance is supplied by a coated polycotton cloth M-roll type surround and from a cloth-type flat spider.

The 5HX140 5" coaxial driver from Faital Pro is built on a cast-aluminum frame, with a water-resistant coated paper cone and pleated M-type fabric surround, and an acoustically transparent cloth dust cap over the compression driver conical horn. The high-frequency compression driver has its own neodymium ring magnet motor system that drives the 25mm Kapton dome shaped diaphragm, with a voice coil also wound with aluminum wire on a Kapton former. This diaphragm fires into a short 90° aluminum conical-shaped horn.

Before computers were broadly available for loudspeaker bass reflex box simulations, engineers relied on "Alignments" for their designs - typically named after equivalent filter functions that the high-pass response of the box was aligned after — for example, Butterworth (B4) and Bessel (BL4) — to name a few. In this article, Claus Futtrup now focuses on the Linkwitz-Riley (LR4) Bass Reflex Alignment.

This valuable tutorial on speaker lead-out flex wire by Mike Klasco revisits the fundamentals, from the trailing ends of the voice coil winding to speaker terminals. How to avoid flex wire whipping, fracturing of lead-out conductors, thermal issues, and corrosion of the solder joints. What types of flex wire and wire gauges are available, what are the advantages of textile fibers and wire testing, are some of the topics addressed. This article was originally published in Voice Coil, April 2024.

This Test Bench explores the exciting SEAS W16NX005 5.25" Metamodal TPCD Midbass Woofer. Part of the SEAS high-end Excel line of transducers, the W16NX005 is the first commercial product available that combines the latest Composite Sound metamodal TPCD diaphragm technology with the typical SEAS high-performance Excel woofer motor design. This midbass woofer includes a metamodal diaphragm and 2" convex dustcap, along with an optimized NBR surround and black cloth flat profile spider for compliance.

Another exciting driver from Neotera, the UF 295 CBS is a new ultra-thin 10" subwoofer primarily intended for high-quality applications in home audio or automotive systems. The UF 295 CBS impresses immediately with its single piece black anodized concave cone assembly suspended by two large rubber surrounds, one on each side, not using a spider for compliance. The cone is driven at its perimeter by a large aluminum voice coil and a unique motor structure of 72 neodymium bar magnets, covered by no less than 10 international patents. This article was originally published in Voice Coil, April 2024.