So i installed 2 12's in my trunk and everything is hunky dory but when it hits my interior lights dim a little. Is my best bet to get a new battery or a cap? My car is feeling sluggish since its gotten a reflash at the dealer. (likely because i used to drive it very hard now its used to my winter driving) but i cant help but wonder if im losing a lot of power. I had an accura TL beside me earlier now he took off at the lights was ahead by half a car before i stepped on it but i still didnt have the jump forward feelin like i usually do. kinda depressing So should i get a cap or battery and do a reset on my ecu and drive it hard?

 

Your 2 12's are HEAVY, so expect it to feel slower. I would only put 1 12" or 1 10" to keep the weight down. I have no experience with capacitors or anything like that, but a optima yellow top should be good for audio systems.

For your ECU, try resetting it and then driving aggressively for a while so it knows how you want it to drive.

 

Is your ground to the battery or to the chasis? Aside from getting a new battery and a cap, grouding it to the battery helps alot.