An acoustic panel is provided with a plurality of grooves in a front face and at least one well in a back face. The well is defined by a first end wall and an opposing second end wall and opposing side walls extending between the end walls. The grooves and the well intersect and have a sufficient combined depth to form a plurality of holes through the panel. The grooves may extend substantially from one end edge to the opposing end edge. The well may be substantially elongate and extend from a position adjacent to, and spaced from one side edge of the panel to a position adjacent to, and spaced from the opposite side edge of the panel. The well may include a substantially flat bottom and receive an acoustic fill material that may be held in place by compression and friction.