PRY4SNO wrote:I seem to remember one of the Seattle area posters being an audio engineer, perhaps he can explain further. Was it Alex, or Pat?
If I understand correctly, it creates a double wave form and cancels out the resonance in a selected frequency range. Tough part is figuring out where your drone is and selecting the right J-tube based on the frequency you're looking to eliminate. Grain of salt disclaimer applies, this is not my field of expertise.
Alex is the engineer, and I think he has done that before on one of his cars. I think its called a helmholz resonator. I see them alot on intake systems in cars and trucks. Just an empty can appendix looking thing that must be sized to cancel out the intake sound. I remove that dumb stuff immediately.
regarding the exhaust, I almost consider a cat and a turbo to be like a muffler. So on a turbo car you can get away with less where on an NA car it would be loud as hell.
I usually do no cat , one resonator, one muffler, If I want it to be fairly quiet and tolerable when I leave my neighborhood at 4 AM. My urq had one borla straight through muffler , and now it has two borla straight through and its on the quieter side for me it sounded much cooler with a single muffler but had some drone for sure.
If you want no drone a good middle ground would be to add a small vibrant (or some brand like that) resonator