A rebuildable low frequency loudspeaker driver has a replaceable diaphragm assembly. In a first embodiment, the peripheral edge of a loudspeaker driver diaphragm comprises a flexible surround and is releaseably supported within a matching basket having a peripheral mounting flange clamping surface to which a rigid ring-shaped clamping member or gasket is releaseably attached. A parts kit includes a replacement cone assembly with a frustoconical cone having an attached annular surround at the large cone end and a flexible spider attached near the small cone end, adjacent the attachment point for the cylindrical voice coil former. The spider includes a rigid ring mounted at the spider peripheral edge and dimensioned to be removably fastened to the driver basket. The driver basket includes a spider plateau region including a valley with sidewalls adapted to receive and center the spider rigid ring. The rebuilding method includes the steps of removing the expended cone assembly, cleaning the magnetic gap (if necessary) aligning the replacement cone assembly voice coil former over the motor pole piece, fastening the spider ring, removing the spacer paper alignment tool, and gluing a new dust cover over the center of the cone.