I pulled out my other Sub1500 and it's spider is separating from the cone as well.
BUT, the spider has not ripped. The glue bead has detached from the surface of the spider and I can clearly see that the spider is not damaged at all.
Bummer, my bottle of 422 Loctite is hard as a rock so I guess it's shelve life is well under 6 years. I'm going to order some more and try and fix this one Sub1500.
No more room for additional speaker boxes in my living room. I have 4 more 18's stored but can't do it. I like the Sub1500 better for HT as well.