Patent ID: 7426280

Claim:
An electroacoustic waveguide system, comprising: an acoustic waveguide having an open end and an interior; a first acoustic driver connected to said acoustic waveguide having a first radiating surface and a second radiating surface, constructed and arranged so that said first radiating surface radiates sound waves into free air and said second radiating surface radiates sound waves into said acoustic waveguide so that sound waves are radiated at said open end, into free air that would ordinarily oppose the radiation from said first surface at a dip frequency; and a source of opposing sound waves in said acoustic waveguide for opposing a predetermined spectral component corresponding to said dip frequency of said sound waves radiated into said acoustic waveguide to oppose the acoustic radiation of said predetermined spectral component from said acoustic waveguide so that the combined radiation into free air from said first radiating surface and said open end is free from appreciable reduction in radiation at said dip frequency.