After speaker re-cap, I'm experiencing sibilance

[bRnzBzh]

I recently noticed my system was sounding dark so I had a tech check the caps in my speakers. He said they were "on the way out" and recommended replacing them. I had him go ahead. Now I'm hearing sibilance, which I cannot stand. Is this likely to go away once caps are burned in?

 

[tmallin]

Maybe, but maybe not. One effect of old caps in speakers is that this typically rolls off the highs. If you replace the caps, you may well now have speakers with much greater high frequency response emphasis than before. I have measured differences of up to 10 dB in the top octaves after replacing caps in the high frequency crossover. That will be hugely audible.

 

[treitz3]

Typically, they will subside a little bit, could take a bit of time though. Maybe 500 or more hours.

Tom

 

[tmallin]

I agree that all caps have a "sound" and some will be a bit brighter than others. I also agree that new caps can take hundreds of hours to break in or settle in and thus reach their ultimate sonic quality.

My previous post was comparing old, now wildly out-of-spec caps that are replaced with new caps of the same nominal value. This is the situation one frequently encounters when restoring 40-or-more-year-old vintage speakers, for example. The example I was thinking of was the caps in the outboard crossover boxes of a pair of KLH Model 12 speakers built in the early 1960s when I did the restoration around 2010.

 

[bRnzBzh]

Thanks for your responses, Tom. this is a somewhat odd situation. The speakers are 18 years old but the manufacturer insists "crossovers last forever", so I was not able to send the speakers to him. I found a local speaker tech who used what he had - Dayton polyester caps. In retrospect, I should've asked whether he could've ordered exact replacements for whatever caps were stock but I was distracted by more pressing life issues at the time. I guess I will just give them some time and see what happens. If they do not improve, perhaps the best thing would be to replace the speakers. I've been considering a speaker upgrade for awhile, anyway.
Best wishes,
Stuart