Cardioid subwoofer system
In general, we say that a speaker, or a group of speakers, radiates with a cardioid pattern when it radiates more energy forward than it does backward. Strictly speaking, however, a cardioid pattern is heart shaped (hence the name) and is represented mathematically by the equation ñ = (1 + cos ó), where ó represents the horizontal angle.
Setting up subwoofers such that they radiate this way is a relatively simple task. One just needs to know what steps to follow as well as how to use one of several measurement systems that provide a transfer function mode.
There exist several cardioid subwoofer configurations, but the method to be followed, as described here, is always the same. This article does not intend to assess the various configurations, but only to show the basic procedures and ease the learning process. The user should choose the most appropriate configuration for the specific application needs.
Throughout this article we'll see measurements performed using SATLive. Phase curves are shown on the bottom part of the image, while the magnitude frequency response will be at the top of the image.
Joan La Roda
D.A.S. Audio, Engineering Department
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http://www.dasaudio.com/documentos_D/ar ... em_V11.pdf