Alrighty, right now I have a 420 watt amp running two 225rms subs, 10". I am looking to get two more subs, 12", which have the same rms(225) so I am going to hook up the same amp. My original system was set up by a friend but I wanna try and do this myself. Right now I am running 10 guage to the amp. I am looking to also add a capacitor. So i am guessing I will need to run like 4 guage to the capactor and off that 8 or so to each amp. Am I guessing correctly or do the amps need to be directly connected and how? Let me know what you guys think. Thanks.