A loudspeaker unit includes a magnetic system of dual magnetic gaps formed with a permanent magnet disk carrying on both sides top and bottom plates and a cylindrical yoke surrounding the plates to form therebetween upper and lower magnetic gaps, and a vibratory system formed with a cylindrical voice coil bobbin carrying upper and lower voice coils for use in the dual magnetic gaps as disposed in half off-set state with respect to the gaps and a diaphragm coupled to upper end of the bobbin, the bobbin being supported by upper and lower dampers with respect to the magnetic system for vibration in axial directions of the magnetic system, allowing the bobbin to be supported at fulcrums positioned above and below voice-coil driving points.