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.

On March 2003, Edward T. Dell, Jr., audioXpress founder, published a complete build project for the SEAS Froy Mk3, an improved version of the original Froy kit, designed by Murray Zeligman, who also designed the original FROY kit. The Froy Mk3 kit uses two W15CY001 woofers and a single T25CF002 "Millennium" tweeter mounted in a D'Appolito configuration. In the subsequent April 2003 edition, audioXpress published a complete review of the Froy Mk3, with measurements by Joseph D’Appolito, and listening evaluation from Dennis Colin.

In this reference article, published by audioXpress in 2008, Joe D’Appolito shares his experiments with loudspeaker evaluation. In the two parts of this article, D’Appolito tries to answer the question: “Of all the measurements available to the designer, which ones are the best predictors of listener preference?" In over 30 years of designing loudspeakers, I have found the following measurements taken as a group provide the strongest predictor of loudspeaker preference available to us today,” he states.

The controversy over subjective versus objective loudspeaker evaluation has raged on for decades. However, to my mind, there is no controversy. These criteria are simply two faces of the same coin. In over 30 years of designing loudspeakers, I have found the following measurements taken as a group provide the strongest predictor of loudspeaker preference available to us today. Want to know more? Read this reference article, originally published in audioXpress, September 2008.

One of the most important speaker building projects published by audioXpress, THOR was designed by Joseph (Joe) D'Appolito, who is world-renowned for his pioneering work on MTM-based (mid-tweeter-mid) loudspeaker configurations. The original THOR transmission-line design was published in May 2002. For this online publication, audioXpress kept the original article unchanged, which has since been updated with availability of the original Madisound/SEAS kit and the publication of a complete kit project on the SEAS website. Read the complete article here.

Audiomatica's CLIO Pocket is comprised by the CP–01 Audio Interface (hardware) and software designed to run on Windows and Apple Mac OSX. This in-depth review shares how it works and what’s possible with this lower cost electro-acoustic measurement system that literally fits in your pocket. This article was originally published in audioXpress October 2015.