The BOSE's LT 6400 is a mid/high-frequency loudspeaker designed for downfill applications in medium to large permanent installations with LT Coherent Zone arrays, or as the principal reinforcement source in smaller arrays and venues with MB low-frequency loudspeakers. For many applications, the large-format 60° x 40° waveguide offers precise coverage and great intelligibility, making this passive speaker a cost-effective alternative to multiple-cabinet line arrays.