What is the difference between a bass-reflex design, closed cabinet and bandpass?

The difference is in the design, the different types of construction: bass-reflex (BR), closed or band-pass produce different characteristic bass response. Closed constructions are mainly used in the SQ range, they play extremely precise and have a smooth frequency response. Bass-reflex constructions are characterized especially by their all-round properties, they can reproduce a powerful as well as musical bass reproduction. Bandpass constructions are a mixture of a closed cabinet with a bass-reflex cabinet in front. Their area of application is primarily in the SPL range, since by means of this construction a high sound pressure can be generated in a certain frequency band.