Abstract: An unbalance arrangement for a compactor roller of a soil compacter includes a first unbalance mass unit rotatable around an unbalance axis of rotation having a first center of mass eccentric with respect to the unbalance axis of rotation, a second unbalance mass unit rotatable around the unbalance axis of rotation having a second center of mass eccentric with respect to the unbalance axis of rotation, an unbalance drive for jointly driving the first unbalance mass unit and the second unbalance mass unit to rotate around the unbalance axis of rotation, and a phase position adjustment unit for adjusting a phase position of the first center of mass with respect to the second center of mass around the unbalance axis of rotation. The phase position adjustment unit includes a spur gear arrangement in the torque transmission path between the unbalance drive and the first unbalance mass unit or the second unbalance mass unit.