it just started? did you change anything? strings, tuning, etc? if not it may be a humidity issue or possibly that fret may be too high...i would check the action at the nut, 12th fret, and saddle. if you can, provide some pictures!
__________________
2006 Martin 16DC-RGTE (bone saddle)
2001 Martin 000-16GT (bone saddle)
2007 Taylor 414ce-SL (koa) (FWI saddle)
|