In {TAIL ~ the presence} of an impulse force, such as the forces used to move the actuator during seek operations, {HEAD ~ a large surface} acts like a drum or stereo speaker 
In { TAIL ~ the presence } of an impulse force , such as the forces used to move the actuator during seek operations , { HEAD ~ a large surface } acts like a drum or stereo speaker
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH