Optimzing cellar for recording

Hi all, my future recording room (7 ft x 18 ft/8 ft high) has a wooden fencing on one of the long sides which separates it from another cellar (typically german). I will treat the other walls (stone) with absorbers(I already had a thread about that), but what about the "open" side? The neighboring cellar is mine, too. It stores all sort of things (furniture, matresses), so maybe it works as a "natural diffusor". Anyway, what do you think? Should I: a) "close" the open side with carpets and hang up some diffusors (to avoid an acoustically dead room)? b) close the open side with 22mm plywood and then go on with regular optimization (absorbers, diffusors? c) just leave it open and trust? Thanks for your help M

Hello, i think you are german because of "typical german cellar" ;) so this should help you: There you will find a description to modify a cellar room. Regards, brick1

Thank you, but unfortunately that does not apply my "special" problem ...I'm through with planning general acoustic measures. I just don't know how to treat that open side ...