BMW Mufflers & Resonators

The BMW muffler consists of metal plates and tubes with multiple holes in them. Between the tubes, there are chambers that cancel out the unwanted frequencies and suppress the annoying noise. Once the sound waves and exhaust gases move into the muffler through the center tube, they bounce off the back wall of the unit and then come back out into the main body. That creates waves that have the opposite amplitude, which makes them cancel each other out.

The chamber where the process of wave collision occurs is called the resonator. Its size is precisely calculated so that the process runs smoothly. The principle that the device works on is pretty simple. When the high-pressure sound wave that is coming out from the first chamber meets the reflected low-pressure wave, they cancel each other out because the two waves add up to zero. That's the way the muffler reduces that tremendous amount of noise produced by the engine.

Another important characteristic of the muffler is that its body is constructed in three layers: two thin metal layers with a thicker insulated layer between them. Such a structure allows the unit to absorb some of the pressure pulses. The muffler itself is manufactured from sturdy materials such as stainless steel and aluminum-coated steel. That ensures the part to function for a long period of time. And the better your muffler operates, the greater performance your vehicle offers.