Walls need a method of acoustically opening & closing the system.

Door panel
Suitable on normal height walls. The last panel is a full height door hinged off the fixed jamb or the prior panel. Doors are normally located at one end of the wall. Typical width is 500-900mm.

dpanel

PROS:
Provides convenient access. Lowest cost closure option. Easy to operate

CONS:
For centre stacked walls, the door may protrude to the side of the stack a little.

Pivot Panel
For centre stack systems only. The single end panel pivots shut and is held in place by 2 latch/handle assemblies. Usually located at the stacking end of the wall.

ppanel

PROS:
Neat stacking. Can be used as an occasional access door.

CONS:
A jamb hung door is a little more cost efficient and convenient

Expanding Panel
This panel has an over-sleeve that can be expanded sideways to lock the wall in place. This is operated by a removable handle in the face of the panel. Usually located at the stacking end of the wall.

epanel

PROS:
Physically & acoustically locks the wall into place

CONS:
Not suitable for access.