Abstract: An improved multidriver loudspeaker includes a low frequency driver having an elongated voice coil former terminating in an inverted speaker cone and a high frequency driver located along the voice coil former. The voice coil former is formed such that the virtual or apparent acoustical source of the low frequency driver is substantially coincident with the virtual or apparent acoustical source of the high frequency driver. The virtual or apparent acoustical source of a driver being the point in space where the sound wave front from the driver appears to a listener to originate at the time that input is applied to the driver.

Abstract: Passive frequency compensation networks are disclosed which extend and smooth the base response of loudspeakers. The compensation networks include a series resonant circuit including a resistor, inductor and capacitor with the voice coil of the loudspeaker connected in parallel with the resistor and inductor. In another embodiment of the invention, a second inductor is loosely coupled to the first inductor to create a tuned transformer which eliminates ripples in the mid base response of the speaker.

Abstract: A loudspeaker apparatus is provided for producing time and phase-coherent sound waves, substantially hemispherical in shape, directed toward a listening area. The loudspeaker apparatus includes a simply-constructed, inverted speaker cone designed to produce primarily low and medium frequencies, a high frequency speaker uniquely positioned above and behind the axis of the cone to supplement the high frequencies, and absorbing material disposed inter alia at a rear portion and at the smaller end of the cone to produce the hemispherical-shaped sound waves and direct them toward the listening area.