Loudspeakers - how best to prolong their lifetime?


Another thread, regarding obtaining speakers "for life" got me thinking about the lifetime of our speakers. Let's assume, for the sake of the argument, that we have a set that we really don't want to lose (just what I own right now). Is there anything that one can do to prolong their lifetime? We'll assume that we look after them regarding the power that we throw at them and that we don't play them excessively loud and blow the cones.

I recall my first "real" speakers, which were Castle Kendals. After a few years in storage, following an upgrade, I went back to them to use in my third system. They sounded terrible when I connected them up and the removal of the grill showed just why - the cone's foam surrounds had disintegrated! I pulled the two sets of spares out, ones that I had obtained from Castle as backups, and they had also gone belly-up. My current speakers have glass-fibre reinforcement so I expect some longevity.

Is there anything to do or do we just have to take what we are dealt?
niacin
i keep my Meadowlark Blue herron 2's covered with blankets when not in use to keep the light off of them and curious hands at bay as well.
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Materials do age and heavy use will cause wear and tear also. However, some speaker manufacturers have been supporting their original products for over thirty years. Meanwhile other speaker manufacturers role out new models and obsolete old ones every two or three years. There are countless numbers of flash in the pan speaker manufacturers that come and go each year.

Simply choose the right speaker company (the non disposable kind) and you won't have to worry for the next 30 years.

If you expect something to last more than thirty years without maintenance/repair then I think you are unrealistic.
Large woofers should be rotated 180 degrees every couple of decades as well, if possible, to prevent stresses on the suspension.

There are a lot of vintage speakers like Viridian mentioned that have doped surrounds.50s through 70s,and probably a lot of other years,I'm missing.These have a syrup looking type of coating on the surrounds to protect them,and keep them flexible.When that liquid sags toward the bottom,I was told to rotate them 180 degrees also.I'm not sure how often this needs to be done.Maybe going by looks,if it's sagging.Keep out of the sun like mentioned above.A lot of hard driving may age the glue holding the voice coil quicker. The foam surrounds could be changed like mentioned above also.With the foam surrounds,if you see the break/hole in them,don't use them.If you use them this way,you could damage the rest of the driver.If you catch it quick enough,they may just need new foam surrounds.The non-foam surrounds seem to keep on going,as long as they're not abused.
I was told to rotate them 180 degrees also.I'm not sure how often this needs to be done.Maybe going by looks,if it's sagging.Keep out of the sun like mentioned above.

It theory yes, but what if your wife refuses to go through with this?