Test Bench: Dayton Audio RS180P-8 7” Reference Series Midwoofer

The 7” RS180P-8 Reference Series midwoofer from Dayton Audio uses a nice six-spoke cast-aluminum frame with narrow 10-mm wide spokes to minimize reflections back into the cone. The cone assembly is composed of a three-part lightweight paper cone that combines Kevlar and glass fiber with the paper slurry. Cosmetically speaking, this is very good looking driver. This article was originally published in Voice Coil, May 2014.

The BMS 4507ND is a unique transducer that uses a neodymium coaxial compression driver to drive a planar waveguide intended for use in line arrays. BMS Speakers patented the two-way compression driver technology in 1997. This month’s Test Bench subject, the 6.5” 4507ND features a 300-Hz to 22-kHz bandwidth (6 to 22 kHz for the tweeter and 400 Hz to 6.3 kHz for the midrange). The rectangular planar waveguide is optimized for 0° to 15° vertical dispersion and up to 120° in the horizontal plane. This article was originally published in Voice Coil, May 2014.

In this Test Bench I characterized the 12BG76-8, a high power handling 12” NBR pro sound woofer from B&C Speakers. This month’s sample submission is in the upper range of power handling in this extensive group with a continuous power handling rating of 1000 W (500 W nominal). Applications range from two and three-way PA speakers and compact two-way designs for high SPL in limited spaces. Features for the 12BG76-8 are similar to most high-performance pro sound drivers, fairly substantial. This article was originally published in Voice Coil, October 2018.

Ported enclosures are known to extend the low-frequency output of loudspeakers by exploiting the Helmholtz resonator effect produced by the compliance of the air inside the enclosure and inertance of the air in the port. This article looks at the problem of port nonlinearity to determine the correct port size, and the acoustic impedance of the port under high air velocity. This article was originally published in audioXpress, September 2001.

This month, I characterized the SW275BD01, a 10.75" high-end home audio subwoofer from OEM manufacturer Wavecor. This driver has a well-appointed feature set that includes a proprietary cast eight-spoke (four twin spokes) cast aluminum frame, a very stiff black mica/paper composite cone, further stiffened by a 4" convex black hard paper dust cap. Suspension is provided by a FEA optimized low-loss (high Qm) NBR surround plus dual 6” diameter black flat conex spiders (dampers). This article was originally published in Voice Coil, October 2018.

2018 was another record-breaking year for audioXpress.com with visits and users doubling the figures compared to our record year in 2016. Want to know which of the topics and stories published online in 2018 were the most popular? We looked at the most-read articles of 2018 in audioXpress.com (which also includes selected articles from Voice Coil magazine), and we created this Top 10 list of news stories and online articles. Here are the results!

Voice Coil January 2019 is now available. This edition focuses on New Materials for Earphones and Headphones and also includes a valuable listing of Earphone and Headphone Manufacturers and a schedule of headphone-centric events for the year. In Acoustic Patents, James Croft looks at a new patent of a multilayer voice coil plate and flat speaker based on the same, while in this month's Test Bench Vance Dickason features a 1" compression driver from Radian Audio Engineering, and a 1" soft dome tweeter from Eminence. This is much more, now available in print and download.

This edition of Test Bench characterizes the 12FCX76, 12” high-performance pro sound coaxial from B&C Speakers. This coaxial driver is similar to the 12FHX76, where the “H” designates that it uses a horn-loaded compression driver, while the “C” in the 12FCX76 stands for conical-loaded compression driver (the “F” is for ferrite). The 12FCX76 uses ferrite motors for both the woofer and the compression driver. In terms of features, the 12FCX76 woofer is built on a 12-spoke (six twin-leg spokes) cast aluminum frame with eight mounting holes. This article was originally published in Voice Coil, July 2014.

The 1" diameter full-range drivers are among the most used transducers in consumer electronics. They are finding broad use in numerous Bluetooth speakers. The driver submitted by Tymphany for this Test Bench fits into that category. The Peerless by Tymphany PMT-40N25AL01-04 is a 25-mm (1”) diameter full-range driver built on a proprietary injection-molded two-piece polycarbonate (one piece for the motor assembly structure and one piece for the protective grill). This article was originally published in Voice Coil, July 2014.

In this Test Bench, I characterized two new 28 mm dome tweeters from Dayton Audio — the RST28A-4 and the RST28F-4 from the Dayton Reference Series. Both are similar tweeters that share pretty much the same platform with the primary difference being the RST28A-4 uses an 30 mm aluminum dome and the RST28F-4 has a 30 mm coated silk dome. This article was originally published in Voice Coil, September 2018.