Scott Helme on Twitter: "The new Power Valve system has a DDE (Dynamic Drone Eliminator) built in to control the bass/hum/drone inside the car. Loud exahust but without the annoying drone in
That exhaust drone, minimized - Helmholtz resonator | Porsche Macan Forum
Exhaust Drone Eliminator With Deep Sound - Paradox Performance Muffler
Eliminating drone in aftermarket exhaust systems. | Veloster Turbo Forum