US Patent 7606384 Spiral line array loudspeaker

A loudspeaker system consisting of a plurality of direct-radiating electro-acoustical drivers arrayed along a spiral line. The acoustical drivers may be directly coupled to an acoustical waveguide without use of adapters or a throat section. The waveguide and the acoustical drivers may thus be oriented along the spiral line so as to produce controlled vertical and horizontal angular coverage with improved phase coherence and reduced distortion. A plurality of phase plugs may be interspersed between the plurality of acoustical drivers to assist in equalizing the sound path to achieve uniform phase at the mouth of the waveguide.