Abstract: A disk drive assembly includes a baseplate housing joined with front and rear covers to enclose a spindle that supports ball bearings and a hub for rotating a stack of magnetic disks. Voice coil actuators are disposed diametrically opposed but offset on each side of a plane bisecting the stack. Pressurizing ports, annular seals and a sealing cap prevent air contamination. Thermally conductive rings contacting the bearings and the housing compensate for temperature differential. Symmetry of the assembly in at least two planes ensures minimal vibration and resonance effects.