How long do speakers last?

I have 15 year old speakers and I cannot remove the sock but they work fine. Do I have to worry about woofers deteriorating or are there electronics (crossover?) inside which won't last forever? I don't use these much.
For example;I have had my JBL 4340's since 1974 and they are as new as the day I purchased them.
What kind if speakers are they?
If they are exposed to direct sunlight it can damage the rubber or foam surround and or if not kept in dry storage can reduce their life expectancy. Otherwise they can last for a very long time.
Actually if your speakers have foam surrounds they could have rotted by now. You should inspect them because if you run them without the surround much you can damage the voice coils. New surrounds are cheap and easy to replace. Once done the speaker is as good as new. I'm presently listening to a pair of Dynaco A 25's that were made in the early seventies. Rubber surrounds so no rot. They work fine and sound pretty good too.
These are dcm time windows. (not sure model)
the foam surround can just get worn out, resulting in a less 'quick' sound.

also, how much do you listen to them? 1 hour vs. 8 hours/day might be a factor in longevity...
As was stated above it depends mainly on the surrounds. If foam then less than 10 years same for butyl rubber and the like. I inherited some 1959 JBLs which work fine, however they use fabric surrounds and compression horns. You need to take that sock off unless some one knows what type of surrounds you have. Most used foam or rubber by then. Therefore I would recommend getting them remounted.
The older a speaker is that much better it will sound, but Capacitors and surrounds will deteriorate in time, if they are good rubber surrounds on the woof's this will not be a problem really, but would still suggest replacing caps for another level of performance, not really because they are necessarily failing, although they do, but newer caps are far more advanced and better material, (with musical results not just scientific results) now available than anytime 10-20 years ago. Beyond that if you do not toast a voice coil or damage them they could last more than a lifetime as long as the glue on the cabinet don't let go, or the wiring does not corrode to some crazy point.
The Reverend Billy Graham has been a speaker for over half a century... :-)

That's an old speaker...
Once I had clipping problems (5 seconds) but it sounds OK. Did that damage the speaker?

Can any good audio repair shop refurbish these speakers?
Or should I bring to speaker rebuilder? (I live in Los Angeles)
You could contact DCM directly and get heir advice. Their phone is 877-326-5683, or thru their website:

I'm sure they still work on older speakers, You could perhaps just send them the drivers for rehab. I'll bet they can even sell you a new grill/sock.
It depends on the material and the enviroment.
Here is a pdf file on Rubber Products: Recommended Shelf Life
See Table I on page 5 for type of rubber, common or trade name and the shelf life.
Billy doesn't sound as good as he used to. Mayebe he was left in direct sunlight.
Rich, I thought the table you referred to was very interesting. Mainly, I was surprised to see such relatively short lifespans for materials that I thought lasted much longer (like silicone rubber and neoprene.)

Might be a good reason to get new cables and speakers every 10 years??

I drive a 33 year old MB that my dad bought new in '72. I now have visions of walking out one morning and discovering all the electrical insulation has turned to dust over night -- yikes!!

Luckily I don't have any rubber parts (so far!) but now I think I understand why some women are concerned over them ;~))