A head stack assembly is provided for interfacing with a flexible medium of a disk. The head stack assembly includes a first head and a second head located substantially adjacent to the first head wherein the flexible medium may be disposed between the first head and the second head. The first head and the second head are substantially parallel to each other and disposed at a static roll angle a and a static roll angle b, respectively, from the flexible medium to impart a curvature to the flexible medium of a disk. The curvature reduces out-of-plane vibrations of the flexible medium and thereby enhances the electrical communicative signal between the flexible medium and the first and the second heads.