In order to obtain a higher radiation efficiency and thereby enhance the sound of bass handbells, Malmark has created a new bell design using aluminum rather than the traditional bronze. These bells are larger in diameter, and they have lower coincidence frequencies, both of which lead to more efficient radiation of bass notes. Using holographic interferometry, vibrational modes of a new aluminum bell are compared with those of a bronze bell having the same fundamental frequency. Sound radiation studies of these large bells reveal a prominent sixth-harmonic partial that is not present in smaller handbells.