This cabinet serves the entire house (one of the reasons I am not too fond of the vertical form factor of the newer SBs). There is a receiver for the upstairs livingroom/dining room area, one for the master bedroom, one for the theater, one for the back yard, and one for the garage.

Because everything is centrally located I only need two SBs to keep the whole house happy and have no need to synchronize beteween them since the second one is for a second music selection.