However, diffraction fringes form in the shadow even when the light source is temporally incoherent. If you let sunlight project through a tiny hole into a dark room, and put a straight edge in the beam, the shadow will have diffraction fringes. Cabinet edge diffraction, which is unavoidable, is the result of any obstruction or cabinet boundary (edge) that changes how the sound wave moves across the surface of the baffle. Obstructions are primarily other drivers (midranges or woofers) and baffle edges and protrusions. By edge Diffraction by an Edge Electrons passing by an edge (Mg0 crystal) x Even without a small slit, diffraction can be strong. Simple propagation past an edge yields an unintuitive irradiance pattern.
The phenomenon by which an electromagnetic waveform diffracts, or bends, as it strikes the sharp edge of an obstacle transverse to its direction of propagation.The portion of the signal that is not cut off by the knife edge continues to propagate, but the edge of the signal bends into the line-of-sight (LOS) shadow region as if to fill the void left by the portion of the signal cut off. Knife-edge diffraction can be used to advantage in radio communications when line-of-sight (LOS) cannot be achieved due to the presence of an obstacle, such as a mountaintop or building, that lies in the path of the transmit and receive antennas. See also diffraction and LOS.