Replacing caps on crossovers?

Has anyone tried upgrading caps on their crossovers? Curious if they experienced any issues with changing the voicing of the speakers in a negative way? Thinking the speakers might be voiced based on lower quality components. 
The negative aspects happen if you willy nilly replace caps that go to ground. Especially with 1980's, 1990's or earlier speakers. You alter the ESR and the impedance makes your amps work oddly.

Series caps are usually pretty safe to change.

When / if you replace coils, keep the DCR the same.
Musichead. If the speakers are working properly there is little to gain and usually you have to do some surgery to get to the x-over risking damaging other parts like the drivers. If you are not happy with your speakers use the money to save for new ones.
Swapping caps is easy. Depending on how good and carefully matched your existing caps are and how good the new cap is your results may range from disappointing to unbelievably impressive. Just no way to tell from the meager details provided.

In terms of voicing, tweaking the speakers tone or frequency response, swapping same value caps doesn't really affect this. Changing cap values changes crossover frequencies and will affect voicing. What most people want is what they already have only with less grain and glare and more refined detail. This you can usually get with higher quality caps without affecting the overall tonal balance of the speaker as long as you stay with the same value caps.
Thanks for the info so far, my speakers are Naim NBLs and the crossover is separate from the speaker and mounts on the back. Looks like it would be very easy replace any given part. The speaker is designed to be used passive with the crossover and active. The gains going active are apparently huge that makes me question if crossover parts are improved will I get part way there?
@musichead   my opinion , sorry, is waisting the time. Is almost impossible get change the sound by  changing capacitor.
try to change the driver or whole speaker
I would definitely change those Solen caps and sand resistors, you would get a more refined sound and clean up that nasal sound solen caps have.

If you can get a schematic of your crossover,  I'll offer some guidance of which parts to replace.  
Musichead. If the speakers are working properly there is little to gain

Hi @Mijostyn : Can you tell me how many times you’ve tried this and what parts you used to come to this conclusion?

Is this book learning, or have you actually experimented?

Because I have the latter, and I conclude you are mistaken.



What you should do is gain some practical experience, cheaply!

My recommendation for inexpensive experiments are Mundorf MKP and Clarity CSA caps.

Should run you about $20 for a pair of caps. Gain knowledge for yourself. If you can't hear a difference, you will learn there's nothing to gain for you.


@bache My speakers (Coincident PREs) only have a single capacitor that filters the tweeter.  I've tried three separate caps on that tweeter and they all sound different.  Replacing the stock Solen for a Jupiter was a significant upgrade.  Will probably try Duelunds at some point...
I've asked Naim for a schematic, see if they provide one. What prompted me on this is I'm replacing some caps on my DAC soon with some Duelunds. I suspect my speakers could be improved as well only worry about messing with the balance of them because they could be voiced with the lower quality parts. I might end up with a different sounding speaker that I don't like.

If you can't get a schematic,  as Erik mentioned,  the biggest improvement is replacing the series caps (in positive lead).... 
It was mentioned to get rid of the Solens... These are only a decent cap,  fairly neutral,they don't do anything terribly wrong,  but as Good Polypropylene goes nothing special.  Personally,  I'd start with any caps that are in the midrange and replace those (especially Electrolytic or Mylar caps (The Solen are much better than both of those).  I'd then take a look at the Series caps in the tweeter and replace those (probably the Solens).  Most if not all caps that run to ground are most likely Electrolytic,  You should be okay replacing any smaller values, but an Electrolytic of any size, I probably would not replace unless you do some resistance measuring.  Otherwise, buy a decent .1 mfd or so Polypropylene, Polystyrene or Teflon and do a bypass on those Parallel caps (goes to ground)... Overall this should provide a very nice improvement without any chance of negative effects.  
Good Luck,  Tim