acoustic operable partitions noise reduction gym dividers acoustical rating automatic walls ACOUSTIC WALLS It is typically superior than other conventional operable wall systems of equivalent STC ratings. ís sound separation capabilities do not deteriorate over the life of the wall. Acoustic performance of Skyfold Autolift Walls as compared to conventional operable walls. All acoustical components are integrated into the Skyfold wall. Once Skyfold is in the down position, acoustical seals automatically engage against the floor and side walls. The only Skyfold element that is located on the side wall is the operating key switch. Skyfold has an excellent acoustic STC rating of 51. A standard Skyfold partition is 260 mm thick with two independent planes of steel panels separated by an 146 mm air space that creates an anechoic chamber.