[quote user="Fraziel"]it supposedly absords /cancels out standing waves [/quote]
Yes to dampen and absorb sound waves so they don't interfere with the action of the speaker cone. A speaker driver produces two sets of sound (pressure) waves when it moves. One in the front which we hear and one behind it.
The waves behind are exactly 180 degrees out of phase with the front. If they were allowed to move back into the speaker then reflect of the back of the speaker, they would interfere with the movement of the speaker cone. This would cause distortion.
The infinite baffle speaker need this out of phase sound "killed" as much as possible. Other speaker designs like bass reflex, bass radiator,transmission, horn etc.. utilises this sound in a different ways to positively enhance the sound coming from the front.
I remember in the 80's a hifi reviewer called Jimmy Hughes recommended removing the inerds from the speakers. He was not taken too seriously however.