Run the biggest resonator you can, or two inline. That will eliminate the drone.

Drone is resonation. Resonators eliminate drone, mufflers muffle noise.

 

I've run multiple resonators in the past and it quiets the note at all freq. ranges across the board. Attempting to quiet the low end frequency as much as possible while accentuating the higher pitch frequency sound.

Which is what I think the Corsa systems are doing. Just not sure the whole Helmholtz Resonator theory applies. Looks like its generally a pretty narrow RPM range used specifically to eliminate drone and not to eliminate the "muscle car" sound and accentuate the "super car" "exotic" sound.

Here's another good example of the two sounds I'm talking about.

 

You don't "cancel", or more correctly, attenuate low frequencies with short Helmholtz tube lengths. The first firing frequency in a V8 equals RPM/60 times number of cylinders. Frequencies lower than 250Hz have long wavelengths and are attenuated by an HH tube 1/2 the wavelength in length to achieve a return wave 180* out of phase with the regular wave, hence attenuation. There isn't enough real estate underneath a car to attenuate the first two orders of exhaust noise so the higher frequencies are targeted for "cancellation." Sorry, this is just the physics of sound.
The 180* headers have a basic sound property/idea built in with no mufflers or resonators. Sounds like poop at low rpms and "whoops" pretty good once the RPMs come up. There's no substitute for 180* cranks and headers on a V8 or siamesed 6 cylinders in a V12 for that sweet sound that ends up as a shriek at its RPM peak.

 

Appreciate the response.

Def not stating I understand the science of it. I just noticed most run a reletivly long tube length to cancel out drone at lower RPM. Then noted that the CORSA systems had what looked like a tiny "J pipe".

I was only trying to figure out why they have such a raspy "exotic" tone compared to the standard burble of an SBC exh systems.

The Corsa extreme line look like a straight through design for the most part.

But the Corsa sport look extremely different.

Here is another example. This is a straight piped setup with what looks like several separate Helmholtz tubes. Sounds great IMO.

 

One thing that can be tuned is how the shell vibrates. Get the shell to vibrate at the desired frequency which can be the higher pitch you are referring to.

 

I think that may be a big part of it as well. Only thing that makes sense. Which unfortunately sticks me with paying a lot for a muffler to vibrate... rubs me the wrong way for some reason.

Wonder if I could try slipping different thickness and length ribbons of SS sheet in the straight pipes and see if I can get one to resonate in a cool way!

 

Raspiest setup I ever ran (LS) was a pair of Borla XR1s.

 

Put a playing card in your spokes. They sounded the best 🤣
I like the reed in the pipe idea! Post video as you experiment please. 👍

be safe, schick

 

A piece of bicycle inner tube hose clamped on the tail pipe may get the desired effect

 

woo woo!!!!

 

I mean if it makes it sound like a ferrari... I don't care what it is!