Well I have a Panasonic stereo in my room. It has a subwoofer output and 6.5" sub that came with it that ran at 8 ohms. I got rid of that and threw two 12" type-r's on it @ 4 ohms. When playing, it puts out the proper amount of bass and then seems almost like a capacitor or something isnt charging fast enough and loosing energy, making the loudness differ in the same bass line. Any way to help this charging problem?
Are you talking about running those Alpines on a home stereo receiver? Most home receivers are rated at 8 ohms and shouldn't be run at 4 ohms. It simply wasn't made for it. Unless you power those with an external or plate amp capable of the ohm load you present to it you could fry your receiver.
My advice would be to build a nice box and get a plate amp. Take the sub out line from the receiver and connect it to the line in on the plate amp.