Nondipole photodetachment parameters for the subshell of are calculated using relativistic random-phase approximation (RRPA). Interchannel-coupling effects on nondipole photodetachment parameters for the subshell are studied with different degrees of truncation of the RRPA. It is inferred from the present investigations that the shape resonance in the photodetachment cross-section profile and the positions of the Cooper minima are sensitive to interchannel coupling. An analysis of the angular distribution of the photoelectrons reveals how the Cooper minima in the dipole and the quadrupole channels introduce a complex energy dependence, with peaks and zeroes, of the nondipole asymmetry parameter .