Hi everyone I have an audio issue with connecting the optoma hd143x projector to a onkyo 608 amp.The projector is connected via hdmi out and freeview,firestick etc via the hdmi in.Do I need to recieve audio direct from the projector via either optical or some other means? The projector only has an audio out from a 3.5mm jack but how do i connect it to the the amp and achieve 7.1 surround sound for all the connected devices? I'm very new to amps and audio equipment so any simple explanations would help greatly.The picture is fine from the projector via hdmi.I have no arc hdmi on the amp or projector. I just don't get how to recieve audio and even after spending countless hours trying to find where I'm going wrong has made it even more confusing.many thanks in advance.