Features: Speaker sound-absorbing cotton is installed in the speaker to absorb standing waves from the low frequency of the cabinet. After installing the sound-absorbing cotton will make the bass clearer and strong. The acoustic propagation will make space larger. The amount of sound absorption cotton in a box should be tested actually. When the bass is smeared install more sound-absorbing cotton. Otherwise reduce cotton. It is a sound-absorbing cotton dedicated to speakers flame retardant and . Tips: Because the cotton is soft and elastic the cotton shape sometimes appears thin when pressed. After natural relaxation the thickness is 3cm approximately.