i have a car stereo that puts out 4x50 watts max (200 total), and had 4 speakers w/ 50w max. i'm not talking about amps and woofers, i mean the stock speakers. i just bought 4 speakers to replace them that are rated for 400 watts, 4ohm each. so does that mean i can now get a stereo that puts out 4x400w (1600 watts total) or will i need to get an amp to use all 1600w these speakers are capable of. if so, then where can i get a stereo online, or a cheap stereo and cheap amp, that will push these speakers to the limit?