The T-118 ultrasonic low frequency loudspeaker box is made up of the foreign top class loudspeaker unit. The structure of the box is designed with the principle of jet air flow and air bag power. It is mainly used as the supplement of the ultra low frequency section in the full frequency system. With excellent low frequency reduction ability, fully upgrade for bass sound systems specially designed, rounded bass reproduction limit the shock effect, it also has a wide frequency response curve of frequency response and smooth pressure can loudly in high power working environment still remains the most perfect bass sound. The use of collocation and NFD series main speakers, is the indispensable tool for senior night bar.