Not disagreeing with you, but how does "jumping" a car work then. . .
Jumping a car off simply pulls the Juice from the battery to start the other car.. in some cases the other battery can take a slight "hot charge" if the battery is good.. The voltage regulator will basically see the draw... and produce the power.. If you have the amperage to spare in your electrical system it will charge the other battery to a certain extent..
But in the case of car audio.. even with a second battery if your pulling more amps than the alt can produce.. it can't keep both batteries up and run the equipment required..
Amps is the measure of flowing Volts produced.. more or less.. Your Alt always produces the same Voltage.. Always.. but what happens when you see a drop in voltage.. is actually a drop in amperage.. the flow of the volts so you read a lower voltage because the supply is not fast enough..
Bottom line no matter what.. Big 3, Better Battery, Upgrade Alt if you need more amps.. then second battery for extra power storage..
Caps dont do a **** thing until the volts drop 12.X volts or lower then it spits out what little bit of power it has.. but will not help you do a **** thing..
They are said to prevent your lights from dimming..thats a lie becasue a drop from 14 to 12 will make your lights dim... and being the power is not pushed out untill 12ish.. defeats the point..
The only place Caps belong are the dozens that are built on an amp to store power while it is in use.. thats the only place..
CapCell's are crap.. some will put your system to 16v... disaster waiting to happen and will over work your ALT.. and being the Car is a 12v system.. it can cause damage...
And so on.. on.. and on..