Measuring Loudspeaker Low-Frequency Response

With the availability of low-cost, PC-based acoustic data acquisition systems, experienced hobbyists can make highly accurate loudspeaker frequency-response measurements without an anechoic chamber. The power of these systems comes at a price. These systems window the time-domain measurement to eliminate room reflections. This, in turn, limits low-frequency response. This article was originally published in audioXpress, June 2012.

In this edition, audioXpress pays tribute to one of its most esteemed and prolific writers, Ron Tipton (1936–2018). In our cover feature, Scott Dorsey details his fascinating visit to the Library of Congress National Audio-Visual Conservation Center. Tom Perazella concludes the construction of his flagship Egg Speakers, Andy Lewis explains more about Back EMF, Peter Lehmann shares his time-alignment design for a two-way speaker, and Ethan Winer shares his experience with the affordable LabNation SmartScope USB oscilloscope. And that's just the start of another great edition, now available in print and online.

Voice Coil September 2018 edition is now available and features all the essential information about this year’s CEDIA Expo event. James Croft reviews a Harman patent for a multi-coil transducer approach to improve the cooling structure of loudspeakers, while Vance Dickason characterizes the ambitious new Dayton Audio Epique E160CF-8 midbass driver and two new 28 mm dome tweeters also from Dayton Audio — the RST28A-4 and the RST28F-4. Now available for download or in print.

Once again, audioXpress focuses on loudspeaker building, design, and testing in its September edition. We have three great speaker DIY projects that are certain to inspire our readers, Geoff Hill explains how speaker measurements are evolving under the latest Audio Engineering Society (AES) efforts, and Richard Honeycutt writes about modulation distortion in loudspeakers. We interviewed Crispin Herrod-Taylor, the designer of the amazing SoundBuckets portable speakers, we explain all you need to know about the latest HDMI Enhanced Audio Return Channel (eARC) specification, and Ward Maas tells the story of Infineon's new energy-efficient multi-level amplifiers.

Dayton Audio announced its new MK442 center channel speaker, designed to complement the Dayton Audio MK402 bookshelf speakers in a multi-channel home theater system. The new 80 watts RMS speaker features two 4" treated paper woofers optimized for low-frequency extension, with a centered 3/4" silk dome tweeter, offering a balanced combination for wide dispersion and impressive room-filling sound. The speaker features an attractive textured, black vinyl finish with 5-way binding posts.

Featuring the same build quality and articulation as the original top-rated MK402 speakers, Dayton Audio launched the added convenience of a wireless connection with the new Dayton Audio MK402BT Powered Bluetooth Bookshelf Speakers. The built-in amplifier on the MK402BT is able to provide up to 80 watts of max output power, while a local control panel allows users to change tracks, volume, and even pause/play songs directly from the speaker itself.

Dayton Audio announced the release of the DTA-2.1BT 100W Class D Amplifier with Bluetooth, a discrete whole system amplifier that provides output for two speakers and a passive subwoofer, which allows for a compact 2.1 setup in virtually any room whether it be an office, bedroom, or even a small home theater. The 2 x 50W output power is more than enough for most bookshelf speakers, and the subwoofer output of 100W is ideal for a small scale subwoofer.

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.