Resonators

Interesting resonator. Problem I see is the tube length in the resonator inside may not be correct for some drones. Drone frequency can vary some from what I have seen from posters using the phone app I used to measure your actual drone frequency. On this page of my thread, Suggestions for muscle car sound muffler without drone, I posted what app you can use to measure drone frequency and the web page I used to calculate the branch resonator tube length (Helmholtz tubes). My tubes are 27" long.