Abstract: A loudspeaker comprises a first diaphragm, a second passive diaphragm, and a drive unit coupled to the first diaphragm. The drive unit is configured to drive the first diaphragm in a direction of excursion upon applying electrical energy to the drive unit. The second passive diaphragm is arranged opposing the first diaphragm. The second passive diaphragm is mainly driven by sound waves emitted from the first diaphragm.

Abstract: A loudspeaker comprises a diaphragm, a tubular voice coil assembly coupled to the diaphragm, a magnet assembly providing an annular gap in which the tubular voice coil assembly is arranged, and a flexible suspension. A longitudinal axis of the tubular voice coil assembly extends along a central axis of the loudspeaker. A longitudinal axis of the annular gap extends along the central axis of the loudspeaker. The flexible suspension has a disc shape and is configured to guide a movement of the tubular voice coil assembly along the central axis of the loudspeaker. The flexible suspension extends substantially perpendicular to the central axis. An inner diameter of the tubular voice coil assembly is greater than or equal to an outer diameter of the flexible suspension.

Abstract: A loudspeaker including a first diaphragm, a second diaphragm spaced from the first diaphragm, a first voice coil coupled to the first diaphragm, a second voice coil coupled to the second diaphragm, and a magnet assembly. The magnet assembly includes a magnet, a magnetic piece and a spacer of non-magnetic material connecting the magnet and the magnetic piece such that a gap is provided between the magnet and the magnetic piece. The first voice coil is arranged at a first end of the gap and the second voice coil is arranged at a second end of the gap opposite the first end of the gap.