How long do good speakers last?

I, too, seem to have a thing for British speakers. Had a great experience w/ATC SCM12 Pro passive monitors (mind-blowingly good sound). 

~6 months ago picked up a vintage pair of big KEF 2-ways from the '80s, 103.2s. The drivers are original, and judging by the wonderful sound, have no issues (the 8" mid/woofer is made of bextrene + rubber surrounds). I know the crossovers had been carefully/selectively worked on, with any caps that didn't test perfectly replaced.

These are 35+ years old and sound amazing. 

My pair of H. H. Scott "bookshelf" speakers from 1967 still sound great for their vintage despite moving across the continent and back, among other travels. They still look good as well.

Funny with foam surrounds, company like JBL has used them on.some of the speakers they sold and they weren't cheap.i have a part of Bose 901....16  speakers with foam surrounds, lol....what a joke ...yes rubber surrounds  can last 60 years .I have woofers made in the 50s with paper woofers and there still good...again buyer beware...they can look great and then you touch the surrounds and they disintegrate....lol

It's all relative, right? Anywho...I have a set of Mirage M760s I bought in the late 80s. I still use them today. I recently acquired a set of Spendor S100s. Comparing on the same system the Spendors offer a different space of sound but I cannot yet say they are significantly better. Tomorrow I will be picking up a set of Focal Kanta 2s to also compare. I am hoping they will be better than both the Mirage and Spendors. I am using a McIntosh MA5200 integrated with a Rega RP8 with Ortofon Red2 cartridge, and McIntosh MCD-7008 CD player. With that said, "good speakers" should last a life time. Some maintenance costs may be necessary and very well is worth it.

Talk about "vintage"?  I am still enjoying my AR-2ax speakers from 1969!  The original ten inch woofers utilized rubber surrounds that have never needed replacement. 

I did have to replace one of the mid range drivers after about ten years - the corroded level controls in the 1980's,  and a burnt out dome tweeter just last year.  Fortunately, Parts Express carries a substitute AR dome tweeter for about $20 that matches the original perfectly.

These speakers still sound as sweet and natural as ever - especially with the latest improvements in analogue and digital sound sources!