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Parallel Capacitors-Theoretical Question

I want to replace the capacitors in my speaker's crossover networks. My Large Advent's came stock with 13uf NPE's which I would like to replace with PIO caps. Unfortunately, PIO caps are unavailable in that value. What's the best way to get to 13uf, (12uf + 1uf) or (6uf + 7uf)?
This is a purely theoretical question and I realize either method would probably sound the same, but I'm wondering if there is a reason why one method would be preferred over the other. Are there phase, impedance or other issues associated with either method. I realize of course that I could simply use 12uf or 15uf and probably never notice anything given that the original 13uf NPE had a 20% tolerance, but in theory, what's the best way and why?
heyraz
marakanetz's avatar
marakanetz
5,473 posts
 
If you decide to go with single cap different from 13uf, you'll simply change the crossover frequency slope.
In case of parallel caps you'll simply have larger tolerance.
The best way is to get a number of caps and choose one(s) that would match the crossover slope closest to the speaker specs or not to replace at all.
jburidan
803 posts
 
I believe it's better to go with 6uF + 7uF.
Some cap makers have 6.2uF & 6.8uF values, e.g., ClarityCap MR (630V).
marakanetz's avatar
marakanetz
5,473 posts
 
The other safe way is to measure the actual capacitance of the original one and than choose out of many to match exactly.
heyraz OP
177 posts
 
Please remember this is a theoretical question. The original 13uf value may have been chosen because of availability and price at the time. The nominal value is probably something else. What I want to do is replace the capacitor with a value as close to the original without creating another problem.
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