Sound quality and the pitch resolution

After testing rkbd The sound quality is not clean even when the audio buffer at 11.6,i have a ddj-sx2 cont,after testing the pitch fader resolution the softwer needs to be more responsive to pitch fader shifting ,i uses serato dj the sound quality and the pitch resolution are magnificent and cannot be compared to sound quality of rkbdj .and i tried different audio files and the result is the same .