Disk device with damper attached to arm of actuator assembly

A disk device comprising:

• a plurality of disk-shaped recording media, each comprising a recording layer;
• a first actuator assembly comprising a first actuator block rotatably supported around a rotation shaft, a plurality of first arms extending from the first actuator block, and a plurality of first suspension assemblies respectively attached to the plurality of first arms and respectively supporting a plurality of first magnetic heads;
• and
• a second actuator assembly comprising a second actuator block rotatably supported around the rotation shaft, the second actuator block opposing the first actuator block with an interval therebetween, a plurality of second arms extending from the second actuator block, and a plurality of second suspension assemblies respectively attached to the plurality of second arms and respectively supporting a plurality of second magnetic heads,
• wherein the first arm which is closest to the second actuator assembly of all the first arms has vibration characteristics different from those of each one of the other first arms, and
• the second arm which is closest to the first actuator assembly of all the second arms has vibration characteristics different from those of each one of the other second arms.