Changing them all seems a bit of a waste of money. They shouldn't be more than 10 years old. You don't have to match the original brand. Just match the value and voltage rating with a good quality polypropylene capacitor. Audyn and Dayton make good caps for reasonable prices. Jantzen and Mundorf will get pushed by some "audiophiles" but they are overpriced and will not make a measurable difference. Solen, a company located in Saint-Hubert, Quebec also make among the best capacitors for passive loudspeaker crossovers. I use their polypropylene caps in my designs, so does TLSGuy. Take note that both Madisound and Parts-Express also carry them: https://solen.ca/product-category/capacitors/?swoof=1&product_cat=fast-capacitors-250v-pa-series-metallized-polypropylene&really_curr_tax=33-product_cat
