you need to figure out what your getting for power now and what your imp rise is, you could always get another amp and run them at 1ohm 1 per sub and gain match them, but by the sounds of it you really dont know much about audio in general (not sayin that in a bad way) but thats how it seems. As said 0.5 is tough on electrical you need to understand a few things though current draw of the amp, voltage dip, output of the alt and take into consideration what you will need for overall power, the kinetik site is nice because they have the calculator on there for this very reason. Also replacing the stock battery is almost always a nice increase...