Muffler cross-section of the pipe, within or outside the room for expansion of the room, undesirable low frequency of extracts from, and in a sound element is the good work, and extracts is a wide spectrum mufflers, widely used in air-conditioning ventilation system in the troughs to reduce the noise of the blower. to enhance the effect, or extracts of a more general use, and extracts the wind is in 6, 8 meters seconds.

  Slightly orifice plate muffler for a pair, the two-tier a perforated board, on the necks of opening air and the air in a splint a loud noise when the structure, frequency and flexible system of the frequencies are a small aperture in the air, a strong and violent resonance friction consumes noise can and muffler orifice plate especially like the noise attenuation of low frequency.

  Extracts from the angle to adopt the round structure is conducive to raising extracts from, reduce losses and reduced of noise, which used steel ( or galvanizing board ), glass material for anybody with the thin glass cotton, by isolated frame ( or steel boxes ) keel to ensure a sound made by the material at gh short of stability. arms ( extracts as the r ~ 100 500mm ) , a small volume, and extracts from the effect of the good points.