Decided to fix my PSW-300 tonight. It was sounding very boomy, and at loud volumes there was the infamous rattle. I'd read enough in the forums to feel like I had a good handle on what needed to be done. I figured the rattle was the spider, and I also expected to see a damaged cone or surround.
Long story short, got the amp plate off, and the woofer nearly rolled out with it. It wasn't attached to anything. Spider was absolutely fine, with a neatly applied thick ring of epoxy around it. No visible damage to the driver.
Anyway, pre-drilled some new holes in the baffle and remounted the woofer, and all is well. Not sure how long that thing was loose in there or why it came loose (perhaps shipping damage) but it certainly sounds better now. Just thought I'd share.