An acoustic filter (100) comprises a filter housing (10) with an acoustic channel (11) and acoustic valve (20) in the channel. The acoustic valve (20) can be moved to along a trajectory (S) between positions (P1, P2). An actuator (30) is configured to actuate the acoustic valve (20) along the trajectory (S). The actuator (30) comprises one or more mechanical elements (31,32). The mechanical elements can move the acoustic valve (20) along at least an initial part of the trajectory. The actuator (30) comprises one or more magnetic elements (41, 42) with a magnetic field (M1,M2) configured to exert a magnetic force (Fm) on the acoustic valve (20). This may help to move the acoustic valve (20) to the second position (P2) along a final part of the trajectory and keep the acoustic valve (20) at the second position (P2). Accordingly the stroke of the valve can be enhanced.