diffraction: Sound waves are diffracted when they hit an object or obstacle with an opening. A good example of this is the bass reflex port on a Sound wall: Here, too, the sound waves, similar to large ocean waves that are refracted and hit the harbor as a small wave, are diffracted throughout the room and radiated non-linearly from this opening.
This diffraction is so great that the placement of the bass reflex tube, i.e. whether it is at the front or the back of the housing, is relatively irrelevant. The diffraction is greater the smaller the aperture is in relation to the wavelength of the sound being reproduced. If the opening becomes larger under the same conditions, the diffraction effect decreases, ie the sound is radiated in a more directional manner.