US Patent 7860265 Diaphragm for full range boxless rotary loudspeaker driver

The design of a diaphragm for a rotary loudspeaker driver that eliminates phase cancellation and therefore eliminates the necessity of a box to acoustically isolate the front sound from the back. The key element of the design of the diaphragm is to use a cross section of at least three equal sides. This allows for the long sides of the diaphragm to create essentially positive pressure only as it rotates and creates a very rigid structure. Further by sizing the cross section to the width of the highest frequency to be produced you allow for a nearly perfect 360 degree radiation at all frequencies.