Abstract: Transducer for converting mechanical vibrations into corresponding electrical signals. Two separate coils are disposed in permanent magnetic fields produced by a magnet assembly. The coils on the one hand and the magnetic assembly on the other are mounted for movement relative to each other. The magnet assembly is structured and disposed relative to said two coils respectively so as to reduce the electromagnetic coupling between the two coils to zero, while having an electromagnetic coupling only between a respective one of said coils and said magnet assembly. In a composite seismometer comprising a transducer of the above-described type and an amplifier, one of said coils is connected to the amplifier input, while the other one of said coils is included in a feedback circuit for said amplifier.