loud ringing sound while playing from the dvd player

[krisoto]

had it install from vcr to in dash dvd player but they say that my dvd player has only composite and no s-video so they convert to hook it up on a existing wireless fm modulator. and it turns out there's a loud irritating ringing audio whenever i played dvd. i told them to put somekind of noise filter but they say (tweeters) it will only reduce to 10% to 15%%, is that true?
it's factory installed vcr on a crysler town and country 2001