SH spectra of the FABIAN HRTF [13]: (a) before preprocessing, (b) after time alignment through phase correction by ear alignment [16], and (c) after setting its phase to zero. The b90 and b99 parameters are shown, indicating the lowest spatial order that contains 90% and 99%, respectively, of the HRTF’s energy for a particular frequency bin [16]. The SH spectrum is defined as the energy of the SH-HRTF’s coefficients at every order n, according to Eq. (A.8) in the Appendix.