surround

I'm using the av receiver (Marantz NR1604) only with 5.1 channel connected, it's right to connect them in the surround back position or best to use normal surround considering that typically in a 5.1 home cinema they are in the side of the listener?

Hi everyone, New to HT and wanting some suggestions on what to implement given my room size. See here for a photo of my room layout: View: https://i.imgur.com/JroYv1d.png Note: On the far RHS, across the 90% of the 4.9m length, are curtains. Note: Still deciding between sub placement...

TL;DR: Are AV receivers / AV amps that upmix from 5.1 --> 7.1 still a 'thing'? I have googled av amplifier with 5.1 upmix av amplifier with dolby IIx etc. Most of the stuff that comes up seems out-of-date, and I can't find any currently available AV amps that advertise Dolby Pro Logic IIx. So...