The short answer is, you'll probably have changed spkrs a few times before anything needs looking at:)
Electrolytic caps deteriorate, esp. the high voltage ones used in PS -- that's usually spec'd at 10yrs! (Yr spkrs don't have a PS.)
Surrounds: the surrounds to look out for are the old foam formulations -- NOT used nowadays. I think the Scan drivers yr Avantis wear have rubber surrounds anyway. Unless you leave the Avantis outside in the sun for a few yrs, forget about it:)
Cheers
Electrolytic caps deteriorate, esp. the high voltage ones used in PS -- that's usually spec'd at 10yrs! (Yr spkrs don't have a PS.)
Surrounds: the surrounds to look out for are the old foam formulations -- NOT used nowadays. I think the Scan drivers yr Avantis wear have rubber surrounds anyway. Unless you leave the Avantis outside in the sun for a few yrs, forget about it:)
Cheers