A low frequency exponential bass horn enclosure employing a bifurcated horn pathway and twin throats, convertible to a variety of front-loaded or rear-loaded configurations without modifications by the use of interchangeable parts, with driver access typically from the front. Optimized for corner placement but fully enclosed horn channel allows for floor or wall use. The horizontal "butterfly" throat is located at the rear of the enclosure and expands vertically, and the vertically arranged horn terminus exhausts in forward-canted splay angles around a partially rectangular back chamber.