How long do good speakers last?


I just ordered a set of Sonus Faber Olympica Nova Vs, my first foray into nice speakers. I turn 51 this month and am hoping these will be the last speakers I ever buy. But it got me to thinking - how long should I expect these speakers to last? Or any good speakers for that matter? Does the foam eventually break down? Issues with general wear and tear? Appreciate your perspectives!
128x128bigtex22
I bought my Tannoy 638’s when I was in the Navy in 1994 on a port visit in Dubai. They are still perfect, though I have replaced a blown tweeter once. 
@oldhvymec....Wow.....

"Infinity InfiniTesimal RS 0.1. 1978 I have 2 pairs...."

I remember listening to a pair of them and thinking:
 "..these would be spectacular in 2 pairs....and a correctly sized sub..."

Did you?  Do you now?  Just curious...;)
If there is not much ultraviolet from the sun on the driver's I bet the electrolytes are bad within 10 years... Or go bad. 
Depends on temperatures and hours of playing. Crossover rebuilding can improve and extent the selflife. Another advantage is no a days there are much better electrolytes, improves the sound a lot. 
I have had a lovely pair of Von Schweikert VR4.5 Silver Edition for over 30 years, and they still perform wonderfully, including several home relocations.  Cosmetically some cat damage to grill cloth, only.....
Box speakers???

Who knows?

My Magneplaner Tympani I-C speakers have been with me since I owned my shop in 1976.  They are as good if not better than ever.

With box speakers, you have cones and other stuff that degrades.  With Maggies, you have the glue that can go bad.

Other than that, I have no idea how long mine will last--45 years and counting!

Cheers!