One channel continually blowing

what that means is....Your coil is damaged. Though your speaker may still play for years to come, you are continually damaging the coil.  The inner part of the coil is either out of round, Distorted you might say, and rubs on the coil itself.  This is usually caused when a speaker is played out of range, It over extends itself trying to keep up with an amp that has its gains turned up. If the rubbing breaks through the coating on the wire and two or more of the coil wires short across themselves it will couse the coil to spaz out.  The shorting out might not be constant, it could only happen every once in a while.  When it does, it changes the ohms your amp sees instantly.

I have diagnosed this type of problem many times and would almost be willing to bet that if you change out the woofers in question with a new set that the problem would disappear.

P.S.  This problem is un repairable and most speaker mfg's will probably not warrantee them.