Fourier spectra of the 2005−2012 data before and after prewhitening multifrequency solutions. 1 cycle d^-1 aliasing is present because all 702 nights of data were obtained at a single observatory. Different amplitude scales are adopted for the different panels. All 64 detected frequencies are statistically significant. The main p-mode frequency region ranges from 4 to 10 cycle d^-1. Most detected peaks in the 0−4 and 10−20 cycle d^-1 region are combinations, f_i ± f_j, of the main pulsation modes f_i and f_j. Additional, statistically less significant, combination peaks can also explain the higher noise seen in those two frequency regions after 64 detected frequencies are prewhitened. The peaks above 20 cycle d^-1 are triple combinations.