I guess my 2ch advice may not be totally relevant as I know nothing about Dolby so better you are deferring to people more knowledgable in this area. Regardless, treating the ceiling will make a massive difference especially in a small room. Velvet curtains while better than no curtains, do sweet FA compared to proper treatment.
Cheers
Good to hear, as long as it sounds better than where it is currently set up (similar depth, twice as much width), I'll be happy!