Inside Passive Cardioid Loudspeaker Technology

An approach for maintaining the directional pattern of high-powered subwoofers and loudspeakers.

By PSW Staff October 24, 2017

Excessive rear low-frequency radiation from loudspeakers and subwoofers often presents a significant challenge to sound reinforcement practitioners. While some solutions have been devised over the years, they’ve not proven entirely effective, especially in larger applications.

The engineering team at Fulcrum Acoustic is addressing the problem with an approach called Passive Cardioid Technology. It’s a patent-pending method of maintaining a directional pattern even when the total air flow is extreme, as it is in high-powered subwoofers.

In this bonus chapter of our “Everything You Wanted To Know About Subwoofers” series, Fulcrum vice president and lead product designer Dave Gunness provides an inside look at this new and still-developing technology, focusing on:

— Producing a cardioid radiation pattern

— The roles of DSP and amplification

— Maximizing efficiency

— And more!

Presented by Fulcrum Acoustic, the “Everything You Wanted to Know About Subwoofer” series features top authors from ProSoundWeb and Live Sound International providing their insights on the evolution, designs, configurations and more of sub-bass systems for live sound reinforcement.

The series offer six (6) chapters plus a BONUS chapter, all available as free downloads

If you missed any of the previous chapters, they’re also still available and listed below:

  • Chapters 1 and 2 (“It’s All About The Bass, And Moving Air,”)
  • Chapter 3 (“The Best Place To Put Subwoofers Is…?”)
  • Chapter 4 (“The Power Alley”)
  • Chapter 5 (“The Aux-Fed Subwoofer Technique)
  • Chapter 6 (“Run and Gun” Subwoofer Arraying Techniques)


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