I have a moderately powered system in max.(components, amp, sub)
Every thump from my subwoofer i notice my headlights dim. Well I notice cars w/ high powered audio systems also have things called capacitors. Will getting a capacitor give my car more juice and cease the dimming??

 

Getting a capacitor will eliminate your dimming issue everytime your subs pound. It will also lighten the load on your alternator and battery as a result, which is always good since they are expensive parts to replace.