True Bass in a Large Space: A Pro DIY Subwoofer Project from 1975!

Part of audioXpress Speaker Focus edition in September 2017, this article by Don Keele, Jr. reminds us of how things evolved in speaker design, revisiting a subwoofer project that uses an Electro-Voice 30W 30" woofer from 1975! In "True Bass in a Large Space," Keele writes, "Getting true bass in a small place is quite easy and straightforward today, but back in 1975, it was not!"

This year we thought our readers would like to know which of the topics and stories published online in 2017 were the most popular for our community. We looked at the most-read articles of 2017 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!

This month’s Test Bench samples came from US OEM, Dayton Audio. I received a home audio 6.5” woofer, the DSA175, from the brand’s popular Designer Series of aluminum cone woofers. Each product in this line incorporates proprietary stamped steel frame with a thin mounting lip that enables front mounting without insetting the driver (surface mounted), high relative XMAX, with paper cones for the DS series and aluminum cones for the DSA series. This article was originally published in Voice Coil, December 2016.

Published in two separate parts in audioXpress October and November 2007, this hybrid amp design is a detailed and interesting project, frequently referenced by other DIY audio enthusiasts. We thought it was time to make it available online in its entirety, in the best possible quality. The article discusses the unity-gain, single-ended MOSFET output stage, the valve voltage amplification stage and wraps up with the power supplies, printed circuit boards, and construction.

Parts Express will hold its annual Midwest AudioFest from July 14–15, 2017 at Parts Express’ headquarters in Springboro (Dayton), OH. The event includes the Parts Express Warehouse Tent Sale, an Audio Swap Meet, a Mobile Electronics Competition Association (MECA) sponsored Auto Sound Competition, and the highlight of the event — the DIY Speaker Design Competition.

This edition of Test Bench characterizes Dayton Audio’s new 6” diameter ultra-low-profile midwoofer, the LW150-4. This is a new ultrathin profile cone 6” diameter midbass driver featuring a six-spoke cast-aluminum frame with a 1.5” total depth. The depth reduction is significant as the motor assembly is housed inside the frame and uses a neodymium slug and a 1.5” diameter return cup that incorporates a T-pole. This article was originally published in Voice Coil, March 2016.

In this article, Vance Dickason explores Audiomatica's CLIO Pocket analyzer. Rather than go into detail regarding all the measurement routines available in CLIO Pocket - audioXpress already published a thorough review in the October 2015 issue - Dickason gives practical examples using measurements for a couple of drivers in the same way he does for his monthly column, Test Bench. This article was originally published in Voice Coil, March 2016.

In this Test Bench, Voice Coil characterizes Dayton Audio’s new 4.5” diameter carbon fiber cone midwoofer, the CF120-4. This new midbass driver from Dayton Audio features a pin-cushion style four-spoke cast-aluminum frame. For the cone assembly, Dayton Audio chose a rather stiff curved profile woven carbon fiber cone with a 1.13” diameter convex woven carbon fiber dust cap. This article was originally published in Voice Coil, February 2016.

I recently purchased a pair of MTX Audio Monitor 5i 5.25″ bookshelf speakers because I needed small monitors for a new computer. I do some audio restoration, so I wanted good sound quality when I wasn’t using headphones. My tests determined that the reviewers were right about the MTX 5i’s weakness in the midrange frequencies. I measured the response and it was not especially flat. This convinced me to update the drivers. This article was originally published in audioXpress, June 2013.

audioXpress February 2017 is one of those issues to read and keep on hand. Learn about Bluetooth 5 and how the new specification promises to positively change wireless audio applications, how to extract multichannel audio from the latest-generation Apple TV, and how to use an oscilloscope to troubleshoot tube circuits. Read reviews of the Vienna Suite Pro processing audio plug-ins and the Primacoustic London 12 acoustic panels kit. Learn how Tom Perazella built its subwoofer with an Ultimax 18” driver from Dayton Audio and how Addie and Whisker built a preamp for high-impedance sources from vintage components, and much more.