sorry i rub you the wrong way.
i know nothing about recording, as i said, so you don't have to take anything of what i say about recording very seriously. i have noticed - however, that a dramatic lessening of this 'open' sound happens when there is thick sound proofing on the walls. carpet. whatever.
i am actually very curious how this would sound if you mic'd it further away. to me, it seems too close and too 'intense.' also, that you hear the 'action.' i'd like to hear the 'impression' of the piece from about 2 ft away with a shepps microphone. (the only way i found out about those - is my husband had one). they are like those hearing devices you can use to listen to someone talking on the other side of the street.
you know, only lately have i become even the slightest bit interested in recording techniques. it really does make a difference how and what you do - and i suppose one could set up quite a few different arrangments and compare. i guess it depends on how much time you have. if i were there - perhaps i could help you? you know, tap the microphone over here and over there. occasionally 'play something' when it's all set up.
square walls are the bane of recording. that's all i know.