A PAP system is adapted for treatment of respiratory disease or sleep disordered breathing. The PAP system includes headgear, a patient interface and a flow generator. The flow generator includes a blower adapted to provide pressurized breathable gas to a patient through the patient interface. The blower is at least partially vibrationally isolated from the patient's head by at least one foam layer mounted within the flow generator to secure the blower. The at least one foam layer is adapted to reduce the amount of transmitted vibration received by the patient. The flow generator further includes a mounting structure limiting an extent of a compression of the at least one foam layer due to the weight of the blower. The mounting structure includes at least one protrusion extending from an interior surface of the flow generator toward the blower.