Basically, a passive radiator is a reactionary device as the name suggests. When a driver (such as a subwoofer) is mounted to a sealed speaker box (enclosure), the physical forward/back movement of the speaker affects the internal air pressure of the enclosure.
Three landforms created by wind are; sand dunes, yardangs (half-teardrop shaped formations hill sized, and deflation hollows (wind swept depressions.
Surfaces loaded with such particles are called desert pavement or reg and sometimes resemble a worn, polished cobblestone street surface. Depositional Landforms Sand dunes are the most noticeable landforms produced by wind erosion and deposition of sediment.The largest dune fields are found in the Middle East and North Africa. Most large dune fields act more or less as closed systems.Once sand enters these systems, it does not leave.olian landforms are found in regions of the Earth where erosion and deposition by wind are the dominant geomorphic forces shaping the face of the landscape. Regions influenced by wind include most of the dry climates of the Earth (Figure 10ah-1).