If you've got the infinity sound system, you've already got an amp under the dash. I don't know the specs, but it's enough to power a set of 5.25" Kappa 2-ways in the back doors and a set of JL Audio 6x9 3-ways in the front doors. It was interesting trying to figure things out until I realized there was an extra wire in the factory harness that I accidentally touched with the power antenna wire from my new deck.