Two zoomed parts of the amplitude spectrum, where the length of the x-axis equals ten times the Rayleigh limit. The spectral window (full line) is placed at the local dominant frequency (cf. Table 1). Dotted lines indicate the extracted frequencies whose amplitude was normalised to the dominant one in that frequency regime (top panel: f₁, bottom panel: f₈). Black dotted lines indicate combination frequencies. The dashed line in the upper panel is placed at the position where the fifth quintuplet component would occur in the case of equal splitting.