Disclosed is an acoustic device comprising an enclosed housing defining an inner volume and having a front and a back; an acoustic port penetrating the front of the enclosed housing; a first and second sense structure attached to the inside of the housing and defining a gap between the first and second sense structures; a front volume defined by the portion of the inner volume between the first sense structure and the front of the housing; a back volume defined by the portion of the inner volume between the second sense structure and the back of the housing; and at least one vent in the first sense structure operatively connecting the front volume and the gap, wherein the acoustic device has a cutoff frequency above approximately 100 Hz.