A sound processing system increases the robustness of surround sound in various playback situations. The server allows for communications with one or more terminals via an internet-type communications medium, while the drive is for controlling, monitoring andor otherwise interacting with at least one motor, electromechanical machine, or other appropriate type of machineprocess. The central portion can be constructed as a two-dimensional block in time and frequency that spans a default cell search bandwidth, a predetermined bandwidth specified by synchronization codes or other signals, or another suitable bandwidth. A resistance between the first and second vias is measured, and the Lextrusion is determined from a relationship with Rtotal, Lv, and resistivities and dimensions of the interconnect and the extrusion monitor structure.