Thoughts on extending speaker life.

too many.

I have saved 'great' stuff for so long, moving it out now bit by bit

physically don't want to pick up anything heavy (bad back, bad knees, bad attitude).

take up too much space

price drops to nothing for most, better to sell when there is more to get out of them.

we are more likely to move on to something 'new to us' than go back.

you know what you will NEVER part with, off with the rest!

Better to have one great set of speakers then several sets of not so great ones. When you can afford better one sell the old ones and move on. Same for all other Hi Fi equipment accept maybe cartridges. Having a bunch to use is great fun.

funny,  no one talked about this   but i do turn drivers180 degrees and tighten the bolts . its b/c of the  big magnet  Russ G  gravity pulling on it   if you look on that back of the driver  you will see a big old magnet on the back of the driver  You won't need Duct tape     

IF the suspension 'sagged', the coil that drives the cone would rub in the magnetic gap, and you would hear it. Never experienced it, never heard of anyone ever experiencing it.

I had a pro re-cone one of my 15" woofer off center. Got it home, mounted, play, what is that?

I had a staple holding interior insulation vibrate loose, fall onto the back of the 15" cone when they were down firing, a weird random sound, you would not think would come from the woofer, what the hell is that. A Sherlock Holmes investigation, I felt so lucky when I found the little bugger hiding under a spider support. 

foam dissolving (resultant permanent sag-off centering), paper cones drying out, cones developing holes, losing acoustic seal, these happen.

If you can get to them, checking, tightening your drivers, especially big ones, is smart  Rotating at that time, seems innocent enough, but, there is potential to compromise the seal at the gasket, so be aware, verify ok, or put back as it was.My 15" woofers, and bigger midrange horns can get loose. Originally 4 clamps/screws, I added a few extra when making new enclosures.

Verify woofer seal for your confidence the problem does not exist: turn your ac system fan off, close the windows and doors, take the grill off, Mickey Hart, volume up, light a match (we used to use cigarette smoke), hold the match as you circle the perimeter, oh happy or oh sad day. Ports: stuff them for the test. While stuffed, listen a while, hear the difference, then open em up, listen again.