Normalized power spectrum as a function of frequency for the set of stellar parameters A (see Table 1) with |R_t| = 0.95 for different values of |R_b| in a single-cavity system. Colored solid lines show p calculated using Eq. (43). Cyan dotted lines show the normalized power spectrum a sum of Lorentzians whose positions and widths were calculated using the resonance condition. The frequency resolution is selected so that all peaks are resolved. In the bottom row, we show the residual of each p and its corresponding sum of the Lorentzian functions.