sentences:  A bass trap generally comprises a core absorbent damp material, a frame, and a covering for aesthetic reasons.Since low frequency resonances in a room have their points of maximum or minimum pressure in the corners of the room, resonant bass traps mounted in these positions will be the most efficient..While porous traps are most efficient at the points of high particle velocity like 1/4 desired wavelength away from the wall Bass traps are typically used to attenuate modal resonances and so exact placement depends on which room mode one is trying to target.