car stereo static coming threw my speakers. HELP!!!?

[JoshuaP]

i have a 98 expedition with kenwood 5x7s and 2 tweeter connected to the front 5x7s, but those were b4 the problem. anyways. i have a lot of static coming threw the speakers. when the factory radio is in no static. when i had my jvc deck in it had static, but it wasn't as loud. now i have a dvd deck in and its even more annoying. its annoying because every time i change the channel or function you can hear a static noise get louder. like its a little BUZZ. my uncle said to install a filter, but i was thinking an amp would get rid of the static. but don't have a lot of money for a new 4 channel amp. just bought a new one for my sub. is there anyways to get rid of the static while with in a reasonable price. o and its not the wires. those are all soldered together. i did it my self so i know its good. and another thing. with the tweeters installed the static is louder because of the high static sound and its right in my face. so is there any ways to get rid of the static??? thank you for the help. if anyone has any good advice!

[Anzmous]

follows ur uncles advice install a filter