The flow of exhaust gases is the source of many physical processes, including thermal, acoustic, mechanical and chemical phenomena with high dynamics of changes. The study analyzes the impact of the entire structure of the exhaust system on the formation of acoustic energy, determining the transmission loss characteristics of its individual components and the entire system. On the example of a structure based on a proprietary solution of an adjustable reactive muffler, the possibilities of shaping the flow of acoustic waves in the process of designing and selecting exhaust systems for internal combustion engines were determined. The study was carried out with the use of the CFD method and a specialized package for advanced simulations AVL AST.