I can't imagine that speaker crossover capacitors would degrade much.
How old are these?
Are any showing leakage?
I would suggest having them tested prior to replacing them.
In electronic components, the power supply capacitors are the most important to replace first. Then the electrolytic capacitors on the boards.
Capacitors rarely fail but they do slowly degrade.
This can be measured as a reduction in their ability to hold their value. A 10,000 uf capacitor might start to measure around 9,000 uf.
Unless you see leakage or your equipment is over 30 years old, your capacitors are probably still good.
Remember that they probably have a 10 to 20 % tolerance built into the design anyway. The circuit would still operate as designed even if the capacitors drift from the stated rating.
I recently recapped a mcintosh amplifier that was 45 years old.
I found that the biggest benefit was eliminating power supply humm.
Changing the capacitors on the board had little audible benefit.
Remember that it's heat that degrades electronic components.