sub phasing in and out

have a polk sub that stopped playing today, read high resistance, messes with the wires inside the sub box and the ohm went back down to 3.8, put it back together the sub started playing again, about to shut the trunck sub stop playing again, i applied slight pressure inward on the sub, and it started playing again, but then stop shortly, it would continue doing this if i held it in, is this a sign of a voice coil going? any help would be greatly appreciated. amp was also checked not the problem

Time for a new sub, there is either a flat spot in the voice coil or the coil is dead shorting.Top Secret, I can tell you but then my wife will kill me.