The Rotten Mule (AKA: 'Mulo Podrido')

[Xeen]

I notice you are running a powered 8" sub.
What most people don't know is while amplifiers have internal capacitors unfortunately they aren't nearly adequate to fully power the amplifier under high demand and subsequently fail to produce sound at their maximum potential.
What this means in layman's terms is your sub isn't hitting nearly as hard as it would be if you added a Capacitor because your amp is starving for power.
I wouldn't worry about using a Cap for your mid/tweet amp because with your set up it's simply not necessary.
If you are interested in knowing more here is a link.
http://www.crutchfield.com/S-xzJ7h4V...itors/faq.html