Dipole loudspeaker response in listening rooms

A dipole loudspeaker radiates from both its front and its rear surfaces, with the radiation from the rear 180° out of phase with the radiation from the front. A conventional monopole loudspeaker is a pressure source, but a dipole loudspeaker is a velocity source. The dipole frequency response in the room thus depends on orientation as well as on room location. The directional pattern of a dipole, however, can provide better auditory localization than a monopole when the dipole is angled into the room. A simulation study is presented of the effects of room placement and orientation angle on the frequency response of a dipole loudspeaker in a room. The frequency response using a two-dimensional room model is computed, and a perceptual model is used to estimate the importance of the room response effects in coloring the reproduced sound. The simulation results indicate that the response of a dipole is more sensitive to changes in room position than that of a monopole, and that it is also sensitive to the angle of orientation within the room.