Effect of Feedback Delay

Since the pulses are equally spaced in time at an interval equal to the loop time $\tau = M/f_s$ seconds, it is periodic and will sound at the frequency $f_0 = 1/\tau$.

Figure 21: Impulse and magnitude response of a comb filter with feedback g = 0.8.

Like in the feedforward case, the spacing between the maxima of the ``teeth'' is equal to the natural frequency.