As a simple example, consider a one chamber silencer with h = S1 / S2 =1/3, at around 400 °C the sound speed is about 520 m/s, with l =0.5 m, one easily calculate the TL result shown on the plot on the right. Note that the TL equals zero when frequency is a multiple of c 2 l and TL peaks when frequency is c 4 l + n ∗ ∗ c 2 l .