Abstract: An upper base/low mid loudspeaker comprises a conical driver and a channel defined by a housing and a central member. The central member has a portion extending into the cone to form a first generally ring-shaped region whose cross-sectional area increases in the direction of sound propagation. A second generally ring-shaped region is defined between a portion of the housing and a portion of the central member. The cross-sectional area of the second region decreases in the direction of sound propagation. The channel continues with a throat and a horn.