You need to research basic electrics a little bit... Caps charge and discharge FAST
Which is of course the whole point.
What a lot of people seemingly fail to realise is that the amps have a bank of capacitors in the powersupply already, so the only time another capacitor is useful is when those are sized inadequately. As a result, the capacitor should be as close to the amp as possible, practically right on the power terminals, or it'll have no benificial effects, and all the detrimental effects the experienced car audio folk around here will tell you about. At the end of the day, stiffening up the rest of your power supply, with a good battery and alternator, will have far more benefit than a cap.
It's important to get good quality cable to wire it all up, but that doesn't mean it has to be expensive. Nearly all copper used in cables is over 99% pure anyway. Despite what the manufacturers will tell you, doping it with silver, titanium, beryllium, gold or any other precious or fancy sounding metal will make no difference to how it sounds. Neither will the insulation, despite the golden ears who will tell you that teflon makes it sound "thin" (or grainy, or harsh) and PVC "muddy" and that the best cable is hand crafted in cotton sleeves. It makes NO difference at all, and people invoking quantum physics, the skin effect or "science can't explain everything" are, at best, unscrupulous. See also
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