Exhaust noise must meet legislation targets, customer expectations and cost reduction
which call for design optimization of the exhaust systems in the design phase. One solution is to use 3 dimensional linear pressure acoustics and calculate the transfer matrix of the muffler. The transfer matrix is the basis for calculating either the insertion loss or transmission loss of a muffler. The 3D simulations in Comsol of different muffler configurations are verified by measurements in a flow acoustic test rig using the two source method.