A sound processing system increases the robustness of surround sound in various playback situations. The tear-away energy absorbing webbing has a top layer load-bearing web and a bottom layer load-bearing web. Further, the first and second brackets are adapted to retain a circuit card therebetween. The sealing member moves between a closed position in which the member occludes the port and an open position in which the port is open. The speed-change motive source includes an electric motor. Included are an arrangement for submitting a request for change to the system, an arrangement for specifying the order in which tasks execute in compliance with data and temporal dependency constraints; and an arrangement for creating a change plan.