Test Bench: The New DE350-8 Ultra-Compact 1" Compression Driver from B&C Speakers

This Test Bench characterizes an ultra-compact (under 60mm diameter) compression driver, along with the B&C Speakers ME10v2 90°x60° coverage horn. The really cool feature of the DE350-8 is the patent-pending phase plug. Inside, the DE350 has a round symmetrical outside channel, and an inside channel with a patent-pending twist for overall improved frequency response. Weighing in at a mere 275 gram, it is an ideal candidate for the new generation of lighter, more compact line array loudspeakers.

Vance Dickason visited Audio Precision's headquarters in Beaverton, OR, where he met with Dan Knighten, AP's Product Line General Manager, to talk about the new Audio Precision APx516 Analyzer. This is a new relatively economical analyzer for the company, with a base price of $6000, which means that the APx516 is ideal for use with remote engineering staff, making it practical for companies to have high-precision test and measurement work being done in multiple locations.

The founder and principal of Redrock Acoustics, renowned for offering engineering and design services, Patrick Turnmire has tested thousands of driver samples during his career, including countless for Voice Coil's Test Bench. Having recently reopened access to its Klippel testing and transducer analysis services, Turnmire shares his vast experience, advising on how to make sure the tests are robust enough to clearly see the loudspeaker performance.

Since the dawn of the digital era decades ago, the timing error known as "jitter" in A/D/A converters has been accused of harming audio fidelity. Some people claim that jitter adds audible distortion and noise, affects bass fullness, and even harms stereo imaging width and depth. This article explains what jitter is, what causes it, and even lets you hear jitter in controlled amounts so you can decide for yourself how damaging it really is. Originally published in audioXpress, January 2024.

This article details how thin-ply carbon diaphragm (TPCD) technology can also be applied to headphones, allowing precise control of diaphragm resonances rather than trying to reduce its negative effects, as the speaker industry already recognizes. As the pioneer of TPCD technology, Composite Sound is now entering the over-ear headphone market with its Metamodal TPCD engineering approach, enabling headphones with better sound quality, improved bass performance, and higher sensitivity.

In the first issue of Voice Coil for 2024, Patrick Turnmire writes about "Diagnosing Speaker Design Issues Using the Klippel Distortion Analyzer." James Croft reviews a Devialet patent. And in Test Bench, Vance Dickason characterizes the new DE350-8 Ultra-Compact 1" Compression Driver from B&C Speakers, and the new LM10n Wide Band Ribbon Transducer from Radian Audio Engineering. This issue also features an updated directory of 2024 Earphone and Headphone Manufacturers and Parts Suppliers.

In audioXpress January 2024, Martin Turesson explains how Thin-ply Carbon Diaphragm (TPCD) technology can be applied also to headphones, and Claus Futtrup writes about Loudspeaker Bass Reflex Alignments. Paul Marchese discusses Composite Amplifiers, Roger Tall explains how a research effort allowed ClarityCap to understand the impact of resonances in capacitors. Our own Jan Didden interviews Robert Munnig Schmidt, while audio expert Ethan Winer explores audible consequences of jitter in digital audio conversion.