I had never seen a capacitor like that! It now makes sense why Fosgates are more expensive.The cap is probably loose inside.
Not all Caps are built the sameI guess the stuff i hear inside is probably the black material whatever is it, makes sense it really sounds like that (like plenty of sand inside), so do I really need to replace it tho?
OK, so turn your music on at moderate listening level and unplug the battery/alternator and see how long that capacitor keeps things playing. Report back with the results.it actually gives my sub more power and gives stable 14.4 power to my amp at any volume.