Start the Loudspeaker Year with Voice Coil January 2025

The first issue of Voice Coil for 2025 is now available and includes a new article by Claus Futtrup about computation of alignments, Dave Morrison discussing Spikes & Isolation for Speaker Decoupling and another valuable directory of Earphone and Headphone Manufacturers and parts. On his Test Bench, Vance Dickason characterizes the new Scan-Speak D3004/666000 metamodal TPCD dome tweeter and the Dayton Audio UMII10-22 Ultimax II 10" Subwoofer.

The fifth article by Claus Futtrup in his series about loudspeaker bass reflex alignments explores the concept of transitional alignments, which is helpful in bridging between filter types. The example details a transitional alignment between Butterworth B4 and Linkwitz-Riley LR4. This article series started 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.

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 the fourth article from Claus Futtrup in his series about the invention, concept, and historical perspective of loudspeaker bass reflex alignments, he explores the Critically Damped Fourth-Order (CD4) bass reflex alignment. This alignment remains one of the least known and hasn't been discussed in literature related to loudspeaker design, even though it allows for interesting output properties. This article was originally published in Voice Coil, August 2024.

Before computers were broadly available for loudspeaker bass reflex box simulations, engineers relied on "Alignments" for their designs. Such box alignments are 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. This article, the third in this series, explores the rarely talked about Inter-Order Butterworth (IB4) alignment, mentioned originally by Richard Small and Neville Thiele.

In Voice Coil October 2024, Claus Futtrup writes about Compliance Alteration, and Mike Klasco and Nora Wong prepared an updated directory of Integrated Electronics for Loudspeakers. James Croft returns with a "Loudspeaker" patent review, granted to industry veteran Michael Levy, and Vance Dickason focuses solely on the eagerly awaited Purifi Audio PTT10.0X04-NAB-01 10" Midbass Woofer.

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.

In this issue of Voice Coil, Vance Dickason continues his exploration of Outboard DSP systems with a review of the Marani Pro MIR4801 Audio System Processor. And Claus Futtrup explores the concept of a transitional alignment between B4 and LR4. Next, Mike Klasco writes about new materials for cabinets and enclosures. On Test Bench Vance Dickason characterizes the new B&C Speakers DE640-16 1.4" compression driver and the latest Satori MR13TX-4 5" TPCD TeXtreme midrange from SB Acoustics.

The first in a series of great value for speaker designers, this article provides an updated approach for the mathematical presentation of the various alignments, applicable to all computerized development tools. This is effectively an explanation of the code available in the Alignment Chart of the Speakerbench web application that Class Futtrup developed in collaboration with Jeff Candy.

In this issue, Vance Dickason kicks off a series of outboard DSP processor reviews, starting with the Danville dspNexus. Next, Claus Futtrup writes about the Critically Damped Fourth-Order (CD4) bass reflex alignment. As scheduled, Mike Klasco writes about New Materials and Technologies for Voice Coils, and there's an updated directory of 2024 Voice Coil winders, converters, lead out wire, and more. On Test Bench, Vance Dickason assesses the new B&C Speakers DH450-8 1" compression driver and the Stereo Integrity M3 3.5" carbon midrange driver.