The THD if a digital PWM modulator is quite high, and a great number of complex technologies has been proposed to improve it. With relatively simple trickery it is possible to achieve fairly excellent performance however, as this simulated example of a DAC shows. Two PWM modulators are combined here, and the distortion of each one is almost completely canceled by the other. They must be combined with very high precision for this to work properly, but that is doable: one idea that should work is differentially sampling them with a floating capacitor. As seen on the plot, approximately two decades below fs the noise and distortion levels are beyond what a perfect 16bit DAC (CD quality) could achieve. This would correspond to an fs (noise shaper calculation speed) of 4.41Msps. The PWM modulators require no calculation other than counting and would in this example be clocked at 12 times fs or ~53MHz. This is only an example. The numbers for an optimized practical implementation would probably become different.