center channel distortion....

ELSock

ok i have a polk center VM20... and i noticed during a couple of different movies that i got some distortion almost sound like static. so now i'm curioius was it just this couple of movies or is my speaker dieing? the movies were The Matrix on Blu-Ray the scene was Neo dodging bullets first time..as the bullets passed they sounded almost to loud and overdriven... only speaker and only time that it happened during that movie.. the other one was in The Day the Earth Stood Still... when the helicopter took off at the beginning, it sounded like there was static in the center.... i hope my baby is ok:(.... any ideas what it could be before i call the big dogs at polk?