I have my NS CR5, I studied double bass for a while, for some reason the sonofabitch hates me when i bow it! the strings have no real 'stick' to the bow. Plenty of screeching and unwanted harmonics even afterthe hundredth rosin application. Is this problem solved by moving to helicores anyone? Its doing wonders for my bowing techniques but frankly im terrified of arco solos above the octave at the moment!