This creates a generally flat surface on {TAIL ~ the top} of {HEAD ~ the dome} with the dome like sides sloping away from, and generally not engaging, the diaphragm 
This creates a generally flat surface on { TAIL ~ the top } of { HEAD ~ the dome } with the dome like sides sloping away from , and generally not engaging , the diaphragm
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH