How long should high quality speakers last?

My speakers are forty one years old, they look and sound like new.

Mike

Speaker life depends upon the design, environment, and usage.  I am not familiar with your speakers.  From a design perspective, ware of the basket of driver is material dependent.  Foam wares sooner than rubber as an example.  The driver diaphragm is also material dependent.  Metal and composites are more durable than paper.  Environmental factors like heat and humidity affect materials of construction.  Aggressive home playing conditions of professional playing conditions shorten life span.  Crossover design with electrolytic caps may need cap replacement after 10-12 years.  You should inspect these items for ware.  If there are no signs of ware and your speakers sound good, don’t worry.  This still appears to be a current model. So that’s comforting from a repair perspective.  I have one of my first low end audiophile speakers, a 40 year old pair of DCM Time Windows still sounding as they did back then in a vaca home in VT.  Do they sound as good as modern designs … no.  But they have not deteriorated and sound as they did back then.  

It all depends on how the speakers were constructed and the materials used.  Cones with foam surrounds deteriorate in a few years and need repair.  Quality speakers with long-lasting materials are a different story.  My woofers were made in 1946.  That’s not a typo.  They will turn 80 next year.  And they sound fantastic.

From the ZU's Definition IV User's Guide: "100 years; cabinet, and drivers, including the Zu 10” drivers; even in direct sunlight".

Play on!

100 years... no need to worry.   You should be able to pass them down for generations....