How Dave Gunness Finally Cracked the Code on Passive Cardioid Subwoofers (Sound Design Live Podcast)

Listen to the podcast interview with David Gunness here. 

In this episode of Sound Design Live I talk with the vice president of engineering at Fulcrum Acoustic, David Gunness. We discuss the improved gain-before-feedback with coaxial speakers, the cell phone material that helped crack the code on passive cardioid subs, and ground-stacked vs flown subwoofers.

I ask:

• “Fulcrum’s revolutionary coaxial designs allow for improved intelligibility, higher gain before feedback…” How does a coaxial design improve GBF?
• When most of us think of a directional subwoofer, we think of multiple elements arrayed together. Even when it’s a single box, like the old Meyer Sound M3D subs, there were multiple drivers in the box to create the directional result. But your cardioid subs have a single driver. How does it work?
• In The Best Place To Put Subwoofers Is… ? Jerrold Stevens writes that it’s best to ground stack your subs if the entire system is ground-stacked, but better to fly the subs if you’re flying the mains. In Comments On Half Space in the section on subwoofer deployment, you write about the height of the subs affecting the difference in path lengths between direct sound and ground bounce and the resulting comb filter. If my mains are flown and my subs are flown, then should the comb filter affect my design choices and limit the subwoofer height? Is there a maximum angle I can use relative to the listener’s perspective to remove the comb filter from the operating range of my subwoofer? Or does the improved SPL distribution with flown subs out-weigh the potential comb filter throughout the audience?
• Tell us about the biggest or maybe most painful mistake you’ve made on the job and how you recovered.
• From FB
  • Nathan Riddel: What is his process for developing the FIR presets? What type of tonal shaping EQ does he pre-bake into the presets for his speakers (if any)? What compromises do the passive-cardioid boxes have or where wouldn’t they be a good idea?
  • Bodo Felusch: What was your biggest challenge by the time you created EAW focused NT series?… and how did you solved it
  • Menno Zijlstra Fulcrum is based on Dsp. How will he see the future develop in the years to come. What can we expect?
• What’s in your work bag?