2 sony XS-L102P5 subs, sound great with deep bass but cones chatter when I hit them real hard

There is a possibility that you may be overpowering or under-powering your speakers with the amp you are currently using or are playing notes below the specified range of "Hz" of the subwoofer causing the sub to sound distorted or as you would call it "chattering".
If the speakers range is 130hz-45hz and your playing notes at 30hz and dont have it tuned at the crossover either on the amp or the stereo to suit the subwoofer, the speaker will try and play the note regardless and will cause the cones to move beyond its range and may cause it to slap the magnet which can damage the subwoofer if consistently played that way. Please let me know if this solved your problem..