Whats inside an exhaust muffler?
What’s Inside an Exhaust Muffler An exhaust muffler usually contains a metal shell housing a network of perforated tubes, baffles and chambers, sometimes with sound-absorbing packing (fiberglass, basalt, or steel wool), and often a tuned side-branch resonator; some modern designs add vacuum- or motor-actuated valves to change sound. Together, these elements reflect, cancel, and absorb …