SINAD is another way of expressing THD+noise. It is the RMS magnitude of the signal divided by the RMS magnitude of the difference between the signal and the fundamental. This measurement is expressed only in dB. With 100% distortion, SINAD, which is the signal including the noise and distortion divided by the noise and distortion, the SINAD would be the √2 or 3dB. Based on the residual distortion, the maximum SINAD would be 65dB. So the range of SINAD measurement would be 3dB – 65dB.