mshan, it is extraordinarily variable. Foam surrounds are always a bad sign and these hardly ever make it past 25 years. Voice coils can burn out or unravel and the driver starts making strange noises. On the other hand I have two pairs of Mirage speakers in my workshop in the worse of conditions. They are 30 years old and sound fine although they don't look so hot. A good ESL like a Sound Labs speaker will last indefinitely.
How long do high quality speakers "last"
I am the original owner of a pair of ProAc Response 2 speakers. They are almost 7 years old, but have never been driven excessively hard. How long (i.e. useful lifespan in years) can I expect these speakers to "last" (i.e. no significant sonic degradation) if I care for them carefully? When they do start to degrade, what mechanical failures and sonic degradations can I expect to occur? Thanks in advance!!!