That's a big space! Definitely more than big enough for an awesome home theatre room.
Yeah the original idea was a double cavity sliding door however 2 meters still feels too small for me. Currently my opening is 3.1m and I still wish it was wider. I found all my cavity sliding doors to rattle quite a bit, I wonder if that's still a good idea if you had a powerful sub.
Currently I have two layers of block out and sound insulation curtains. (Gotta have that since I didn't want either the entrance or the inside of the room to view the back of the curtains. ) Will let you know in a month's time (or after restrictions are over) if they effective at all.
sounds good , thanks again for sharing