Abstract: A system for providing the effect of an extended soundstage comprises a pair of stereophonic loudspeakers, each having a movable or vibrational element driven by a pair of voice coils including a principal or main voice coil and an auxiliary or enhancement voice coil. The principal voice coil of each speaker is driven in a customary manner from one channel of a stereophonic amplifier, while the enhancement voice coil is driven in a reversed phase sense from the output of the opposite channel, and sound is effectively provided over an extended apparent source having dimensions beyond the spacing between the loudspeakers.

Abstract: An electrically driven loudspeaker is coupled to the atmosphere, which is to carry sound to the human ear, through a hollow coupler the inlet end of which has a cross sectional area comparable to the effective area of the loudspeaker, said cross sectional area decreasing progressively from said inlet end to an outlet end of substantially smaller cross sectional area. In a specific embodiment of the invention, an exponential horn is formed within the confines of a loudspeaker cabinet enclosure, and the inlet end of the horn is coupled to the electrically driven loudspeaker by means of the hollow coupler also formed within the cabinet enclosure. The outlet end of the coupler has the same cross sectional area and shape as the inlet end of the horn.