Speaker Re-cap. How do you know when?


Howdy. Looking for input on speaker capacitors & their life span. I have a set of Infinity Renaissance 90's and the bass seems to be thinner than it used to. Thinner meaning not as strong, feel it in your chest type bass. The speakers go down to 27hz, so I know form the specs and experience that it can happen. Reason I am asking about the capacitor, is "back in the 70's", I had a pair of Pioneer speakers that occasionally would literally blow the insides out of a cap. I'd go to Speaker City grab a new one & solder it in till she blew again.
Question; Is there a chance the caps are old & hammered or am I searching the wrong area? What have you folks experienced? Are there even caps in the woofer cross-over’s?
Speakers are powered by Krell KCT pre & Krell FPB300cx.
PS - The surrounds look like new.
Thanks for any input and advice.
-John
jsd52756
Howdy
You may want to open the speakers and find the largest capacitors in the crossovers, then verify if those caps are in paralell with the woofer(s).
Assuming that Infinity used a second or higher-order crossover, you will find an inductor in series with the woofer(s), then a cap in paralell. If that cap is leaky, some of the symptoms could be weak bass or too much midrange, which sounds like weak bass.
To avoid frequent replacements, buy caps rated for at least 100 volts. Nonpolar caps are better for crossover duty than regular, polar caps.
Good luck
Getting better caps can also improve the sound. Silver wire or higher quality copper can also be a big improvement.
Make sure there are no air leaks. Make sure all drivers, binding post, etc...are all secure.

Electrolytic caps usually last about 20 years, so it's probably time for a recap soon anyway. If possible, use all film caps. I believe those speakers are somewhat forward already, so I would avoid Solen caps.