True- discrete separation will always be better. But if the mix is the same between Q8 & SQ, which most of Columbia's music was, a fully functioning SQ Surround Master, Audionics S&IC, or Fosgate Tate comes pretty damned close. Back when the HK 8+ was sold SQ decoders had extremely poor separation. The pictured Sony SQD-1000 pictured was one of them. You couldn't hear the quad mix at all. The newer decoders reveal the mix quite well.