Properly Equalized: Best Practices for Loudspeaker Equalization and Tuning

Charlie Hughes knows about directivity control and how a loudspeaker system should sound good and measure accordingly. This article offers basic recommended guidelines that will not only help to develop good equalization and tuning practices, but also will go a long way in improving the overall sound quality, regardless of the application. This article was originally published in audioXpress, January 2022.

Do you know what the crossover filters are doing to the response of the loudspeaker system? Some of you might have measured the frequency response of the loudspeaker system to determine what’s happening through the crossover region. However, most designers only look at the loudspeaker’s on-axis response. It’s equally important, or perhaps more important, to know what’s happening off-axis. Let’s see how loudspeaker modeling can be used to help with this. This article was originally published in Voice Coil, August 2017.

Loudspeaker modeling files are most often used with acoustical modeling programs such as EASE, Focus, CATT-Acoustic, and others to help determine how well the loudspeakers cover the audience areas and how much “spill” there is on the room’s surfaces. It is important to have accurate data about the characteristics of the loudspeakers that are used in the models. In this article, we will detail some of the requirements to help assure good measurement data for use with loudspeaker modeling. This article was originally published in Voice Coil, April 2017.

In a previous article (Loudspeaker Sensitivity: What’s a Watt Anyway? April 2010 Voice Coil), I examined the topic of loudspeaker sensitivity and how it may or may not relate to the overall sound pressure level (SPL) produced by a loudspeaker. The output capability of the amplifier driving the loudspeaker is of equal importance to achieving the target SPL from the direct field of a loudspeaker. This can also be related to the driving signal or the intended program material. This article was originally published in Voice Coil, May 2010.

In this tutorial Charlie Hughes addresses the question of “How do I align a subwoofer with a full-range loudspeaker system?”. He answers the problem by addressing the three main issues of crossover frequencies, relative output level and delay. This article was originally published in Voice Coil November 2011.

In this article, the author addresses possible scenarios when measuring loudspeaker input impedance at drive levels closer to those used in actual operation, including problematic examples with vented loudspeaker enclosures and constant voltage distributed system transformers. This article was originally published in Voice Coil, February 2011.

The question of phase response often arises when measuring loudspeaker systems. In this article, the author reviews setting the receive delay within a measurement system so that the displayed phase response is the “correct” one. This article was originally published in Voice Coil July 2011.

All-pass filters are perhaps one of the most overlooked and misunderstood tools for the general audio practitioner. Much has been written about their use to yield more linear phase response through the majority of a loudspeaker’s passband. They can also be used to optimize the directivity and magnitude response of a loudspeaker system. Perhaps we should first look at exactly what an all-pass filter is.

The specification of a loudspeaker’s sensitivity is probably one of the most common, yet perhaps one of the most misunderstood. In the past, and still today, it is common to see the magnitude response of a loudspeaker system reduced to a single number as a sensitivity rating. Article originally published by Voice Coil, April 2010.

Horns are often used in loudspeaker systems for a variety of reasons. One may be to provide increased acoustical loading to the driver attached to the horn. This helps to increase the sensitivity/efficiency. Another may be to provide some control over the radiation pattern of the driver attached to the horn. Article originally published by Voice Coil, November 2010.