How to Calculate an Exhaust Silencer

Did you leave your textbook back in your dorm room?

Simply calculate the destructive interference pattern within the resonance chamber. This generated sound wave pattern is engine specific.

Another way is simple restriction, but that has some problems. Can you tell us what some of those problems might be?

Or as redfred asks, why not go back to your room and look in your textbook? Or has the money for books been repurposed for beer?

It is a series of Helmholtz resonnators build from tubes which have an R and L characteristic and volumes which play the C role. The design is quite complex because of the distributed mass of the gas which must be considered due to high frequencies. The principle is simple making it work is much more complex.