No treatments that I remember, but I wasn't really looking for anything like that at the time.
The room was a 'working' sound room meaning that it was not meant as a show room. As I remember, the inside walls were not covered, so you could see the 2x4 framing and there was lots of other stuff in the room. There could well have been damping material between the studs and I would not have noticed. It was not a lively room.
At the time, their new sound room was a pile of lumber in a corner of the plant.
