Unbalance exciter modular system for an unbalance exciter for a vibratory plate for ground compaction, comprising: - two different designs of rotatably mounted unbalance shafts , on which an unbalance mass is provided in each case in order to generate an unbalance, wherein the two different designs are provided for two different drive types; - an exciter housing which at least partly surrounds the unbalance shaft ; and comprising - at least two bearing devices for the rotatable mounting of the unbalance shaft in the exciter housing , wherein the unbalance shaft has two bearing seats , on which bearing devices mount the unbalance shaft ; wherein - the exciter housing has a central part ; - the exciter housing has two end parts which are arranged at ends of the central part ; - the central part has a hollow-cylindrical recess, in which one bearing point is provided for each of the bearing devices ; - the central part is designed to optionally accommodate one of the unbalance shafts for one of the two different drive types, namely a first drive type and a second drive type; - the central part is identical for both drive types, whereas the respective unbalance shafts are different for the two drive types; - the modular system is designed for an unbalance exciter according to the first drive type, in which the unbalance exciter can be driven by means of a drive device provided outside the exciter housing of the unbalance exciter; and wherein - the modular system is designed for an unbalance exciter according to the second drive type, in which the unbalance exciter can be driven by means of a drive device provided inside the exciter housing of the unbalance exciter. - two different designs of rotatably mounted unbalance shafts , on which an unbalance mass is provided in each case in order to generate an unbalance, wherein the two different designs are provided for two different drive types; - an exciter housing which at least partly surrounds the unbalance shaft ; and comprising - at least two bearing devices for the rotatable mounting of the unbalance shaft in the exciter housing , wherein the unbalance shaft has two bearing seats , on which bearing devices mount the unbalance shaft ; wherein - the exciter housing has a central part ; - the exciter housing has two end parts which are arranged at ends of the central part ; - the central part has a hollow-cylindrical recess, in which one bearing point is provided for each of the bearing devices ; - the central part is designed to optionally accommodate one of the unbalance shafts for one of the two different drive types, namely a first drive type and a second drive type; - the central part is identical for both drive types, whereas the respective unbalance shafts are different for the two drive types; - the modular system is designed for an unbalance exciter according to the first drive type, in which the unbalance exciter can be driven by means of a drive device provided outside the exciter housing of the unbalance exciter; and wherein - the modular system is designed for an unbalance exciter according to the second drive type, in which the unbalance exciter can be driven by means of a drive device provided inside the exciter housing of the unbalance exciter. <EOS>