A test stand assembly includes an electric machine (4) for driving and/or loading a test object (1), which is connected by a connecting shaft (2) having an adapter flange (3) to the electric machine (4). The assembly has a constant, predetermined moment of inertia, and the mass and the moment of inertia of the adapter flange (3) are selected in such a manner that the resonant frequency of the system formed of test object (1), adapter flange (3), connecting flange (2), and electric machine (4) for driving and/or loading the test object (1) lies between the idle frequency and the partial load frequency of the test object (1).