The first box was executed some where around 1975. Pine shelving was layered and overlapped to fashion channels, and tenons. This became practical with the advent of drywall screws and battery powered hand drills.
The wood became a second skin as it was fashioned to tightly hold a human body with inspiration from Egyptian sculpture.
The airtight seals also allowed them to become speaker enclosures
They where like psychological pupas — the person emerging was some how changed — at least for a while.
The first box allowed for the speaker to function while the person was inclosed.