12-inch SS BW SF musical instrumental speaker, these state of the art speaker features Kevlar impregnated cones and a high efficiency magnet structure to provide outstanding sensitivity, reliability, and performance. Voice coil material with an aluminum ribbon wire Polyimide-impregnated fiberglassformer Nomex stiffener Solderless diffusion welded OFHC copper leads.reducing the tendency of the cone to distort the shape of the voice coil, thus avoiding rubs and scrapes. Superior power handling results from the increased stiffness, especially with large cone excursions. This cone also offers lower distortion than a paper cone due to a greater dampening of unwanted cone vibrations.