an improvement in small round loudspeakers of popular standard types used in vehicle assembly is obtained by modifying a standard - sized basket in a manner to provide a polar array of special mounting openings located on a concentric mounting circle of larger than standard diameter , thus allowing the use of a larger cone for improved performance and allowing the loudspeaker to be mounted in different - sized popular mounting hole patterns in the baffle panel ; for example an aspect of the invention enables the &# 34 ; 6 . 5 inch basket &# 34 ;, associated with asian - built vehicles , to be fitted with a larger - sized cone used in the &# 34 ; 170 mm basket &# 34 ; associated with european - built vehicles , thus providing a loudspeaker , with the improved performance of the larger cone , that can be installed in a range of different baffle panel cutout sizes and configurations of either type of vehicle . in a twist - lock embodiment , an array of elongated slots , typically four , configured in the rear side of the peripheral mounting flange of the loudspeaker , enables twist - lock installation and removal , by engaging a corresponding array of specially - shaped lock tabs associated with the baffle panel . the lock tabs may formed on a sheet metal ring that can be attached to the baffle panel by bolts , screws , rivets or other fasteners prior to installing the loudspeaker . a forward - facing raised landing surface of the loudspeaker flange , which normally carries protruding mounting screw heads , is left clear to provide an unobstructed flat surface for adhesive attachment of the surround suspension of the larger cone .