The Polk MW-650X Magnet Slipping Issue

transmaster

I have read the reports of the magnets slipping on the MW-650X drivers. Well I happen to have a pair of MW-6503s manufactured April of 1988 that have roasted voice coils, I decided to see just what it would take to dislodge the magnet on one of them. I can report not much, a light horizontal tap from a hammer froze the voice coil, and a stronger tap dislodged the magnet. When I pulled the speaker apart the adhesive strips were perhaps ? of an inch wide, not much considering the weight of the assembly. The adhesive appears to be a heat activated ring placed on top and the bottom of the magnet as the spider assembly is placed in an alignment jig. There is room for at least 2 inches worth of whatever the adhesive used was. All it would take, as has been reported, is a short vertical drop of the speaker to seize the voice coils. With this knowledge in mind I am going to give the original MW-6503?s in the other Monitor 10B the JB Weldbond treatment. I have already done this on the replacement pair in the other 10B.