The composite horn has two or more small horns mounted to a big base horn. The small horns can be flat, contoured, knurled or with the features of spot welding or staking. Composite horns are generally used on big applications such bumper or interior of automobiles. Also, composite horns are used on applications where there may be a clearance/reaching issue. It is possible to enter the inner of complex workpiece and make effective welding without dissambleing any parts.