Coronal power spectra for the MHD wave modes. The figure on the left shows the average power spectra for the slow, Alfvén, and fast velocity projections, indicated by the orange, blue, and green curves, respectively. For all modes, the coronal Alfvén power spectrum peaks around 4.5 mHz, with the frequency indicated by the vertical black dotted line. The red dashed curve is the averaged power spectrum of the velocity projection v_z at the location of the driver. The peak frequency of the driver is shown by the vertical black dashed line. The figure on the right shows the normalized average power spectra for slow and Alfvén projections.