What is "kempul"

A component of the Javanese gamelan, the kempul is a set of pitched, hanging, knobbed gongs, often made of bronze, wood, and cords. Ranging from seven to ten inches in diameter, the kempul gong has a flat surface with a protruding knob at the center and is played by hitting the knob with the "soft end of a mallet." "The wooden mallet used has a ball shape head with heavy padding on a short wooden handle. The number of kempul gongs present in a gamelan ensemble varies but, "although there can be two to ten kempul on one separate rack, it is common to have five kempul hanging on the same rack as the Gong ageng and gong siyem" (two larger gongs).