Test Bench: The SW26DBAC76-4 Shallow-Mounting Subwoofer from SB Acoustics

This Test Bench article analyzes the popular SW26DBAC76-4 10" low-profile subwoofer from SB Acoustics, specifically designed (and patented) for applications that require a subwoofer that will fit into very shallow-depth enclosures. The SW26DBAC76-4 has a unique and interesting feature set that starts with an extremely shallow 79.5mm (3.13") cast-aluminum frame. The outside rim of the inverted cone is attached to the outside perimeter of the spider, and moves with the cone assembly. The inside diameter of the spider that would normally be glued to the voice coil assembly is then connected to the motor structure. This is a clever design.

The PTT6.5M08-NFA-01 6.5" Midrange is the fourth woofer from Purifi Audio to be examined in Test Bench. This midrange is pretty much identical to the previously examined PTT6.5X and PTT4.0X woofers, and includes the same constant Sd surround, cone edge stiffening ring, and low magnetic hysteresis motor design. However, the PTT6.5M08-NFA-01 is optimized to have higher efficiency (91dB at 2.83V8/1m) for use with multiple woofer three-way design configurations. This article was originally published in Voice Coil, January 2023.

Haptic motors are finding applications in gaming, music, VR/AR, and therapeutic/wellness. The Transporter is a patented transducer that delivers faster more accurate bass and is designed to work with the main audio driver in headphones. It subtly vibrates against the user’s skin to produce an extra dimension that can be described as a high-fidelity extension. Silmon J. Biggs and John Steinberg, the two masterminds behind Taction Technology share the story of this development. This article was originally published in audioXpress, January 2023.

A wave of new developments promises to solve the most pressing need for people with milder hearing loss, allowing mass-market hearables to supplant Over-the-Counter (OTC) hearing aids with less stigma. Andrew Bellavia suggests the FDA’s OTC hearing aid rule (October 2022) includes assumptions that are quickly becoming obsolete as recent developments illustrate. This must read article was originally published in audioXpress, January 2023.

This article looks at the practical test and measurement of bone conduction technology, as used in product development for headsets and in-ear devices. It showcases new possibilities for manufacturers to better evaluate device performance, since no appropriate test equipment and methods were commercially available until now. The approach, complements a Head-and-Torso Simulator (HATS) with an actuator capable of generating structure-borne sound in the artificial ear. This way, a realistic simulation of the human structure-borne voice signal for in-ear headsets is possible.. This article was originally published in audioXpress, January 2023.

For this first issue of 2023, Voice Coil compiled a set of valuable headphone and earphone driver vendor directories, updated with the latest factories. The remainder of this issue is centered on Test Bench characterizations of two very innovative drivers that Vance Dickason has received. The first one on the Test Bench was the PTT6.5M08-NFA-01 6.5" Midrange from Purifi Audio; The second driver was the already popular SW26DBAC76-4 10" shallow subwoofer from SB Acoustics.

Multiple perspectives to inspire you in the new year. A Market Update on Bone Conduction Transducers, an article on the development of the Taction Transporter haptic transducer, and a valuable article by Hans W. Gierlich explaining an effective approach for testing structure-borne sound applied to in-ear developments. Andrew Bellavia writes about why the FDA’s OTC hearing aid rule could be quickly obsolete, Adam Levenson introduces the new Audio Foundry automotive audio development platform, and René Christensen makes its debut with audioXpress, writing about simulation techniques