means for reducing a gain of a head Positional Error Signal(PES) within a disk vibration frequency range; wherein said disk vibration frequency range includes frequencies between at least 1000 Herz and at most 3000 Herz; and

means for increasing said gain of said PES within a lower frequency range; wherein, said lower frequency range includes frequencies between at least 16 Herz and at most 800 Herz;

wherein said voice coil drives an actuator arm positioning a head gimbal assembly for a read-write head communicatively accessing a track on a rotating disk surface to generate said PES;

wherein said PES is a function of said head gimbal assembly responding to mechanical vibrations in said rotating disk surface by providing said read-write head with radial motion toward said track;

wherein said head gimbal assembly further comprising:

means for moving said slider parallel to said disk surface toward said track, when said disk surface is flat, by said actuator arm moving, through a flexure, said slider mounted to a flexure at a bias angle to a principal axis;

means for radially moving said slider toward said track when said disk surface is bent, by said flexure responding as said disk surface is bent, through said bias angle, causing said slider to move radially toward said track.