Bass traps are low-frequency sound absorbers specially designed to damp low frequency sound and reduce the effects of standing waves. Proper bass trapping is a key important piece of acoustical treatment of a room. Low-frequency sound waves can be tough to control. Controlling low frequencies is harder than controlling mid or high frequencies and generally requires more effort.
Bass traps placed in the corners of the room, where the maximum sound pressure in the entire frequency range is produced, are the most effective way to get rid of low frequency issues and reduce resonances in the room. Make sure to complete your room plan including bass traps in order to clean up the low frequency response within a room and maximize the effectiveness of your total treatment.