Abstract: A measuring apparatus for measuring the force factor of a dynamic loudspeaker driver comprises first and second terminals for connecting a dynamic loudspeaker driver to the measuring apparatus, an amplifier configured to generate a voltage, a voltage measuring device configured to measure the voltage present at the first terminal, a displacement measuring device configured to measure the displacement of the membrane of the dynamic loudspeaker driver with respect to the magnet, and an electric/electronic device connected between the amplifier and the first terminal. The measuring apparatus is configured to operate in a first mode of operation the amplifier to generate a voltage and to operate the electric/electronic device to have a low impedance during the first mode of operation, such that the voltage is substantially present at the first terminal in order to displace the membrane with respect to the magnet.