Before performing a transfer path analysis (TPA), the engineer needs to think about the right modeling of the source’s interface with the receiver. In practice, the vibration transfer from the source to the receiver is often modeled with three translational forces in each connection point. Mechanically this corresponds to a ball joint connection, which cannot transfer any moments. This study compares different complexities of interface descriptions on the industrial example of an electro-magnetic roll control (ERC) in a passenger car.