capacitors do work... for what they are intended for... starting electrical motors primarily.... they are a scam in the car audio industry however.
:edit:-- a capacitor provides up to 3 times the amperage for extreme draws... like starting a multi-wound Electrical Motor, a 1/2 hp motor may run constantly at 6.5 - 8 amps under light to moderate loads, but in order to get it started it may require 21 amps or more... it cannot and does not increase the voltage... voltage in = voltage out..period.
so, in the car audio industry if you dont have the battery power FIRST, then whats the reason for a cap? A battery, by nature, has it's own natural capacitance. please correct me if I am wrong... (oh, and ya gotta prove it-- lol!)
(we are talking about the larger .5 + caps that people put in their trunks to "give the sytem that extra KICK."... not the components used internaly in an amplifier-- those are usually in Micro farads )
This article was written for the home audiophiole..not car audio... even tho it was referenced a few times, the basic concepts are arguable at best. some are truthfull... but overall, hearing, like opinions, are subjective...