I have bought the Pioneer 515, with the single wireless surround speaker. I'm very happy with everything BUT... I am not thrilled (YET) by the single rear speaker... Maybe it's just the placement? But for me it gives good surround sound only to the person directly in front of it... off to one side the sound seems to come directly from it, rather than from the walls as promised. Has anyone got the 515 and know how to get a full surround sound for all viewers?