Replacing caps on crossovers?

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?