Test Bench Dayton Audio’s UMII10-22 Ultimax II 10” Subwoofer

This Test Bench characterizes the Dayton Audio UMII10-22 Ultimax II 10" Subwoofer, a recent example of the upgraded, high-performance designs that succeeded the brand’s original Ultimax subwoofer line. Available for now in four diameters (18", 12", 10", and 8"), the common feature set for the new line includes a large aluminum shorting ring and aluminum pole sleeve for lower magnetic distortion, a lightweight and rigid woven carbon fiber cone assembly, high Xmax, with a frame and motor designed with extensive thermal venting, all optimized for compact sealed enclosures.

Vance Dickason has spent some time characterizing the new Scan-Speak D3004/666000 tweeter, the first to combine a metamodal Thin-ply Carbon Diaphragm (TPCD) dome with the company's AirCirc motor. This new Scan-Speak tweeter is not a common "evolutionary" design but a joint manufacturing project with Swedish company Composite Sound to develop new second-generation TPCD diaphragms with the characteristics and able to rival the performance levels of a beryllium dome.

Voice Coil May 2025 is now available and in this issue, Vance Dickason explores the popular miniDSP Flex HTx processor, while Mike Klasco dives into the world of microspeakers. For this issue's Test Bench, Vance Dickason characterizes his first driver from the new Italian brand RS Speakers, a new TW 104.28 N/Ag 1.1” tweeter, and next measures the 27TFC/T 1” Soft Dome Tweeter from the SEAS Prestige Titan Line.

The 6.5" MR16TX-8 TPCD Midrange from SB Acoustics' prestige Satori line targets hifi and high-end audio applications, and expands the company's already significant investment in TPCD Textreme diaphragms. The cone assembly consists of a curvilinear inverted single piece, "bowl" shaped TPCD cone, glued to an inverted NBR surround, with the remaining compliance coming from a flat BIMAX spider. The motor is an FEA-optimized neodymium magnet and a 1.4" voice coil with a nonconducting fiberglass former.

This Test Bench characterizes a 1" conical exit compression driver from Faital Pro that was measured along with the brand's STH100 elliptical Tractrix flare horn (80° × 70°). Driven by a voice coil wound with aluminum wire on a high Qm non-conducting Kapton former, and powered by a neodymium ring magnet, the HF110 compression driver targets applications such as stage monitors and PA speakers with a 2kHz recommended crossover frequency (second-order or higher high-pass filter).

The third of a series of product reviews of outboard DSP hardware, this article explores the MIR260A DSP processor from Marani Pro Audio. Supported with expert measurements performed by Charlene Chow on a flagship APx555B analyzer (courtesy of Audio Precision), Vance Dickason looks at this professional DSP processor with two inputs and six outputs, and a more cost-effective model from Marani.

In his exploration of available Outboard DSP systems, Vance Dickason explores the Marani Pro Audio MIR4801, the company's flagship DSP processor with four inputs and eight outputs. 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 by Michael Marani and Simone Castrucci, both from SEED Electronics, Guangzhou, China.

The first in a series of reviews of outboard DSP processors available in the market and of interest to loudspeaker engineers, this article explores an extremely versatile and powerful DSP audio processor and DAC, crossover, and control center for any audio system. The dspNexus comes with balanced inputs and outputs, USB, S/PDIF and Bluetooth aptX HD, and processing is handled by a latest-generation Analog Devices SHARC DSP, with Audio Weaver as the programming interface.

In this article, Vance Dickason explores the use of digital signal processing, and specifically Outboard DSP, an increasingly viable solution to create a complete active crossover design, contained in a programmable unit that can be delivered with multiple presets for different usage scenarios or even configured by the user, according to the system in place. This inspired Vance Dickason to begin a series of product reviews of multiple outboard DSP processors, and this article is a preamble for the project.

The new 7.5" coaxial driver from SB Acoustics' prestigious Satori line is built on a rather stylish aluminum-cast frame, totally open below the spider, with a cone featuring SB's proprietary Egyptian Papyrus material with a three-roll coated cloth-type surround, driven with a 1.52" diameter voice coil and neodymium magnet. The 1" tweeter is comprised of a coated cloth-type dome diaphragm, powered by a neodymium motor, which incorporates a resonant back chamber design.