Spectral maps of 3C 84 between 22 and 43 GHz. The total intensity is represented by the contours, using the contour levels at 1, 2, 4, 8, 16, 32, and 64% of the peak flux at 22 GHz, with a cut-off of 8σ_I for all epochs. The black ellipse in the bottom left corner denotes the convolving circular beam size of (0.35 × 0.16) mas at a position angle of 18° for all epochs, and the black dash in the bottom right corner denotes the projected distance corresponding to 4000 R_S and 0.37 pc. The dashed box indicates the optically thin jet region that was used for the cross-correlation calculations as described in Sect. 3.2. The black arrow marks the knot deflection point, as mentioned in Sect. 3.2.