When you turn down the volume of audio, the low and high frequency harmonics are nonlinear distortion because our ears are sound pressure sensitive and nonlinear instruments, so you can feel that the low and high frequency harmonics become thin and weak even you are replaying a very hi-fi music. But Fair-Sound Audio DSP Plug-ins adopts superexcellent filters, thereby provides hi-fi listening effect at the condition of even very small volume.