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