Upon power down, the switch over to a line to line {HEAD ~ configuration} allows for {TAIL ~ the series connection} of two windings, necessarily contributing the back EMF energy from a pair of windings to the voice coil 
allows for
Upon power down , the switch over to a line to line { HEAD ~ configuration } allows for { TAIL ~ the series connection } of two windings , necessarily contributing the back EMF energy from a pair of windings to the voice coil
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH