balanced/xlr vs. unbalanced/ single ended

would a true balanced pre/processor to amplifer (Meridian) sound measurably better than single ended/ unbalanced. all the interconnect cables are 1 meter. the speaker cables are 14 ft. for the fronts and 42 ft. to the rears. all high end/expensive cables.
Does anyone have a fully/true balanced Meridian processor/amp combo into passive speakers?