An apparatus includes a frame and a surround element that couples a diaphragm to the frame such that the diaphragm is movable in a reciprocating manner relative to the frame. The surround element includes a half-roll element having a concave apparent area and a convex apparent area. The concave and the convex apparent areas are disproportionate. Another apparatus includes a diaphragm, a frame, and a surround element that couples the diaphragm to the frame such that the diaphragm is movable in a reciprocating manner relative to the frame. The surround element includes a half-roll element having a horizontal span and a free-length. A ratio of the horizontal span to the free-length is constant throughout the half-roll element. According to another example, an apparatus includes a landing and a half-roll element adjacent the landing. The half-roll element includes an inner portion, an outer portion having a variable thickness, and a transition portion located between the inner portion and the outer portion.