In For both Cs3(Sb1-xBix)2Br9 and Cs3Sb2Br9-xIx the Raman inspection allowed to confirm the single-phase structure of all the endmembers. Moreover, the reported results, confirmed by the XRD evidence, point out a redshift of the modes as a consequence of the cell expansion and the substitution of heavier ions that enlarged the reduced mass of the vibrational unit. The Raman features for the mixed samples are consistent with a two-mode behavior and the mixed phonon landscape which can in turn play an active role in the electronic response.