Capacitor

I came so close to doing that. To be honest, it came down to a combination of they are so big it would mean outboarding the whole crossover, which in itself would be a huge project, and then there was the problem of even getting them. At the time when I was looking into it everything was backordered, and I just was not into waiting however many weeks or months. Okay yes there was the factor of spending more on the crossovers than the speakers. But having done this I know the crossovers ARE the speaker!  

When researching mine I tracked down a fellow in Kirkland who I believe had built some speakers using these caps. Was focused at the time on selecting mine. But now you make me curious to go back and see about maybe hearing them. And seeing them! These things are HUGE!!!

Where is the cap? What is the circuit? In the absence of solid understanding the safest course is to use only same value caps. They can vary by a bit but in percentage terms, okay? The values you are talking while small in absolute terms are large in percentage terms.   

I have swapped caps out many times, and always with great results. But always paying close attention and keeping values identical or worst case within a few percent. Most parts are within a few percent tolerance anyway. Take this approach and you will avoid a lot of potential problems.