I am getting worried. I recieved my Corelli 370F G & D , and Helicore orch. med. They have been incredibly terrible so far. The Corellis are horribly scratchy , thin and just painful to hear myself sound so bad. The helicores are a little muddy ; but that I dont mind. The issue with them is the bow response , or lack their of. The obligatos grabbed better. I have tried little rosin , lots ; Hard rosin , medium , soft , ;I tried fiddling with the bridge , etc.,. No Dice...They sound good for jazz so i will hold onto them for that....but i cant afford to spend 100$ on new Ob's (borrowed previous set for trial).