Electrodynamic actuator with vibration compensation and method of tuning a sound system with such an actuator

Electrodynamic actuator (1, 1a . . . 1k), which in particular is designed to be connected to a plate like structure (24) or membrane (27), wherein the electrodynamic actuator (1, 1a . . . 1k) comprises:

• a primary drive system (2a, 2b), which comprises at least one annular primary voice coil (3, 3a . . . 3d) with a center opening (O1) and an annular primary magnet system (4, 4a, 4b) with a center opening (O2) and with an annular outer center magnet (5) or outer magnets (15),
• wherein the at least one primary voice coil (3, 3a . . . 3d) has an primary electrical conductor in the shape of loops running around a primary coil axis (A1) in a primary loop section (L1) and wherein the primary magnet system (4, 4a, 4b) is designed to generate a primary magnetic flux (Φ1) transverse to the primary electrical conductor in the primary loop section (L1), and
• wherein the primary voice coil (3, 3a . . . 3d) is movably coupled to the primary magnet system (4, 4a, 4b), and
• wherein the electrodynamic actuator (1, 1a . . . 1k) additionally comprises:
• a secondary drive system (6), which comprises at least one annular secondary voice coil (7) with a center opening (O3) and a secondary magnet system (9) with an inner center magnet (10),
• wherein the at least one secondary voice coil (7) has a secondary electrical conductor in the shape of loops running around a secondary coil axis (A2) in a secondary loop section (L2) and wherein the primary magnet system (4, 4a, 4b) and the secondary magnet system (9) are designed to generate a secondary magnetic flux (Φ2) transverse to the secondary electrical conductor in the secondary loop section (L2),
• wherein the secondary drive system (6) is arranged in the center opening (O2) of the primary magnet system (4, 4a, 4b),
• wherein the inner center magnet (10) is arranged in the center opening (O3) of the at least one secondary voice coil (7) and
• wherein a movable part (33a . . . 33c) of the secondary drive system (6), which comprises or is formed by the at least one secondary voice coil (7) and/or the inner center magnet (10), is movably coupled to the primary magnet system (4, 4a, 4b).