With our special “BAM Mechanism” design, air movement inside the housing is optimized, allowing the BA-SS to produce deep bass without the distortion and muddiness normally reproduced by BA unit earphones. The design theory of this breakthrough earphone rests on a single driver directly connected to the circuit – uncomplicated by the presence of other drivers. The BA-SS is a handmade product, made by Japanese sound engineers with a full-focus on ideal sound with no compromises. This is our flagship model of the BA series and our premium model in the Balanced Armature category.