A combined exhaust gas noise silencer consisting of a system of hollow elements with a mutual housing comprising a front face of the silencer connected to the supply pipe of exhaust gases, and a rear face of the silencer with an outlet from the rear face of the silencer, where the original—inlet exhaust gas (İ.sub.p) carrying a noise wave is divided into at least two flows—an exhaust gas flow (İ.sub.z) carrying a shifted noise wave with delayed wave length, and an exhaust gas flow (İ.sub.n) carrying a non-shifted noise wave, which are subsequently combined into a common exhaust gas flow (İ.sub.s).

An exhaust muffler for an internal combustion engine includes a housing. A plurality of partitions are disposed within the housing, defining a plurality of chambers. An inlet pipe and an outlet pipe are also disposed within the housing and both the inlet and outlet pipes include a perforated region. The perforated region permits fluid communication between the inlet pipe, outlet pipe and the plurality of chambers. To attenuate engine noise, the perforated regions of the inlet and outlet pipes are positioned at opposite ends of the housing, forcing the exhaust gas to pass through each of the plurality of partitions and chambers, thereby damping the sound waves with minimum effect on engine back pressure levels. Alternatively, the perforated regions of the inlet and outlet pipes may be aligned in a cross-flow chamber.

The present disclosure provides a muffler system that can effectively reduce exhaust noises. The muffler system includes an exhaust passage and a first muffler. The exhaust passage is configured to allow a flow of an exhaust gas. The first muffler is an expansion chamber muffler and disposed in the exhaust passage. The first muffler is situated upstream of a first position in a flow direction of the exhaust gas. The first position is located away from an upstream end of the exhaust passage by one third of an entire length of the exhaust passage.

An exhaust muffler for an internal combustion engine includes a housing. A plurality of partitions are disposed within the housing, defining a plurality of chambers. An inlet pipe and an outlet pipe are also disposed within the housing and both the inlet and outlet pipes include a perforated region. The perforated region permits fluid communication between the inlet pipe, outlet pipe and the plurality of chambers. To attenuate engine noise, the perforated regions of the inlet and outlet pipes are positioned at opposite ends of the housing, forcing the exhaust gas to pass through each of the plurality of partitions and chambers, thereby damping the sound waves with minimum effect on engine back pressure levels. Alternatively, the perforated regions of the inlet and outlet pipes may be aligned in a cross-flow chamber.

A sound generation assembly unit, for an exhaust system of an internal combustion engine, includes a sound generation module (16) with a sound generation module housing to be arranged at an exhaust gas guide element (12) of the exhaust system (14). At least one loudspeaker unit (20) is arranged in the sound generation module housing (18). A rear volume module (30) includes a rear volume module housing (32) and a rear volume (34) formed in the rear volume module housing (32). The rear volume module housing (32) is connected or can be connected to the sound generation module housing (18) for the acoustic coupling of the rear volume (34) to the at least one loudspeaker unit (20).

A combined exhaust gas noise silencer consisting of a system of hollow elements with a mutual housing comprising a front face of the silencer connected to the supply pipe of exhaust gases, and a rear face of the silencer with an outlet from the rear face of the silencer, where the originalinlet exhaust gas (?.sub.p) carrying a noise wave is divided into at least two flowsan exhaust gas flow (?.sub.z) carrying a shifted noise wave with delayed wave length, and an exhaust gas flow (?.sub.n) carrying a non-shifted noise wave, which are subsequently combined into a common exhaust gas flow (?.sub.s).

A sound generation assembly unit, for an exhaust system of an internal combustion engine, includes a sound generation module (16) with a sound generation module housing to be arranged at an exhaust gas guide element (12) of the exhaust system (14). At least one loudspeaker unit (20) is arranged in the sound generation module housing (18). A rear volume module (30) includes a rear volume module housing (32) and a rear volume (34) formed in the rear volume module housing (32). The rear volume module housing (32) is connected or can be connected to the sound generation module housing (18) for the acoustic coupling of the rear volume (34) to the at least one loudspeaker unit (20).