All Hevos cabinets are vented box types. A vented-box is a cabinet with a so called vent, usually placed at the front side of the cabinet. This vent connects the interiour of the box with the outside. Here you see a schematic drawing of a Hevos cabinet. The vent is at the bottom and is an integrated part of the cabinet.
Wrongly, many people think that the purpose of this vent is to lead the air inside the cabinet to the outside. Reality is a bit more complicated. The air mass inside the vent is triggered at a specific frequency by the moving air energy from the back of the loudspeaker frame and is going into resonance. The whole secret is to make this air mass move at the right time and at the right frequency. Crucial in this matter are the position and the dimensions of the vent. Within certain limits the cabinet designer can choose at which frequency the vent is tuned. Continue reading