Abstract: A moving coil speaker may comprise a frame, a magnet assembly fixedly mounted to the frame and having a central axis, first and second annular gaps defined by the magnet assembly and concentrically disposed about the central axis, a voice coil at least partially received within the first annular gap, a cone coupled to and driven by the voice coil, a secondary coil at least partially received within the second annular gap, and a mass coupled to and driven by the secondary coil. When variable electrical audio signals are sent from an audio signal source respectively through the voice coil and the secondary coil, the coils and their respectively associated cone and mass reciprocate back and forth in opposite axial directions, with the reciprocal movement of the cone being counterbalanced by the reciprocal movement of the mass.

Abstract: A vibration reduction assembly includes a mass and an actuator. The mass is configured to be attached to a rear plate or a frame of a speaker in a manner that allows the mass to move along a longitudinal axis of a pole of the rear plate. The mass is sized to yield a force that is equal in magnitude and opposite in direction relative to a force generated by moving components in the speaker and acoustic pressure of the speaker. In one example, the actuator is configured to move the mass in phase with movement of a voice coil of the speaker along the longitudinal axis of the pole and in an opposite direction than the voice coil movement. In another example, the actuator is configured to move the mass out of phase with the voice coil movement and in the same direction as the voice coil movement.

Abstract: A vibration reduction assembly includes a mass and an actuator. The mass is configured to be attached to a rear plate or a frame of a speaker in a manner that allows the mass to move along a longitudinal axis of a pole of the rear plate. The mass is sized to yield a force that is equal in magnitude and opposite in direction relative to a force generated by moving components in the speaker and acoustic pressure of the speaker. In one example, the actuator is configured to move the mass in phase with movement of a voice coil of the speaker along the longitudinal axis of the pole and in an opposite direction than the voice coil movement. In another example, the actuator is configured to move the mass out of phase with the voice coil movement and in the same direction as the voice coil movement.