Used phase shifting in order to get a pseudo room effect in the previous posts. Now imitating the additional phase shifting as used by my marantz full logic SQ decoder. This means the phases of the requested rear speakers are doubled in order to get a reversed phasing of the sinwave. For me it works, which means all instruments with doubled phasing sound from the rear -left/right switched crosswise. The acoustical middle actually is positioned in the middle of the room and all four sides Front/rear/left/right have a middle position between the respective speakers. I use 4 identical 3way active speakers Most digital decoders use this effect too. Please tell me about your system, what does it sound like ? This effectt is available from midi and means that the listener is placed between the speakers. The file for testing is TaikoTrance 061117CQ.mid ; https://1drv.ms/f/s!AmWYApv7ZBFG5UoPDZkDk7NLcqXr ; Albrecht