Sub Problem

Not sure why but my subwoofer is giving me some problems lately. The best way a can describe it is when theres bass I can hear it more then feel it. Like my sub is acting like a regular speaker instead of a sub. I havnt changed anything on it in the last 4 months so im not sure what did this. And for whatever reason it does it more when im listining to the radio then if i was listining to a cd. ANY IDEAS??????

Give us some more information. What sub do you have, what amp do you have, and what are the RMS on each? It sound like the sub is distorting, how high is the gain and bass boost turned up on your amp? The radio is lower quality then cds and tends to distort more, which would be why it sounds worse then cds.