Abstract: The invention is a reinforcing system with vibrating plates of stringed musical instruments, as well as a method for determining the optimal placement of reinforcing braces on those plates. To determine the optimal size, shape and location of plate reinforcements, the plate is caused to vibrate at a known frequency, and the nodal and anti-nodal areas of the plate are mapped. Bracing of a size and shape corresponding to the mapped nodal areas are affixed to the plate, and the acoustic properties of the plate are then measured. Thereafter, the braces may be repositioned to optimize the tonal qualities of the instrument based on both objective and subjective criteria.