Acoustic muffler for a two-cycle motor of a motorised work device

The silencer (100) has a flow channel (12) aerodynamically formed between a silencer inlet (11) and a primary chamber (15) such that exhaust gas predominantly flows into the primary chamber based on mass inertia and flows back toward to the silencer inlet after filling of exhaust gas in the chamber so as to produce back pressure toward to a combustion chamber (13). Total length (Lges) of the channel and depth of the primary chamber is less than computed length. A catalytic converter is arranged in the flow channel and/or in the primary chamber.