Abstract: A passive cardioid acoustical system, or loudspeaker, is described which is driven with a single electrical signal and provides a useful reduction of low-frequency sound intensity in the rearward direction while producing relatively high low-frequency sound intensity in the forward direction. This is accomplished by an acoustical circuit which modifies the magnitude and phase of sound radiated by the interior side of a vibrating diaphragm or diaphragms, and combines it with the sound radiated by the exterior side of the diaphragm or diaphragms, so as to cancel part of the rearward radiation and reinforce the forward radiation. The passive cardioid loudspeaker described employs an improved acoustical circuit which allows improved efficiency, as well as greater flexibility with regard to the size, maximum output, and effective frequency range of the loudspeaker, as compared to prior art.

Abstract: A passive cardioid acoustical system, or loudspeaker, is described which is driven with a single electrical signal and provides a useful reduction of low-frequency sound intensity in the rearward direction while producing relatively high low-frequency sound intensity in the forward direction. This is accomplished by an acoustical circuit which modifies the magnitude and phase of sound radiated by the interior side of a vibrating diaphragm or diaphragms, and combines it with the sound radiated by the exterior side of the diaphragm or diaphragms, so as to cancel part of the rearward radiation and reinforce the forward radiation. The passive cardioid loudspeaker described employs an improved acoustical circuit which allows improved efficiency, as well as greater flexibility with regard to the size, maximum output, and effective frequency range of the loudspeaker, as compared to prior art.

Abstract: A method is provided for creating a series of digital signal processing (DSP) filters to improve the transient response of a loudspeaker, wherein the loudspeaker is formed of multiple components. The method includes generally six steps. The first step involves identifying a substantially linear, time-invariant, and spatially-consistent loudspeaker mechanism causing transient response distortion. The second step involves characterizing the identified mechanism. The third step involves determining the characterized mechanism's two-port response. The fourth step involves establishing a target response for the characterized mechanism. The fifth step involves calculating an ideal filter to achieve the target response. The sixth step involves designing a cost-reduced filter based on the ideal filter.

Abstract: A low frequency horn apparatus including a throat (20), barrel (30) and mouth (40). The barrel (30) includes a series of chambers (50 and 60) wherein the cross-sectional area of each chamber in the series increases linearly from one end of the chamber to the other. The rate of linear increase is greatest in the first chamber 50 in the series. The chambers are in communication with one another so that sound waves entering the throat aperture (20) of the first chamber (50) in the series travel though each chamber in the series and exit the series of chambers through the mouth (40) of the last chamber (60) in the series. Sounds waves may be created by an electroacoustic transducer (70) that includes a cone. Further, the cross-sectional area of the mouth (40) may be less than the cross-sectional area of the cone (78).

Abstract: A loudspeaker system having a cross-cabinet horizontal array of loudspeakers for collectively generating a common acoustical wavefront when respective drivers associated with each of the loudspeakers of the array are similarly driven. The loudspeakers are secured to each other such that adjoining horn side walls for adjacent ones of the loudspeakers are substantially parallel to each other and are relatively deep in relationship to the total length of the loudspeakers, i.e., the length of the sidewalls is about 80% of the depth of the entire loudspeaker. Each horn is angled about 30 degrees off a central axis thereof to provide 30 degrees coverage in the horizontal plane and includes a first, essentially untapered, section which provides the aforementioned coverage in the horizontal plane and a second section having a taper of about 30% to prevent diffraction of the wavefront at the edges of the horn.

Abstract: A down-fill speaker for a large scale sound reproduction system is formed from a cabinet having generally rectangular and trapezoidal cross-sections along respective vertical and horizontal axes thereof. Upper and lower loudspeakers are supportably mounted in the cabinet in a generally vertical array and separated by a separator wall. The upper and lower loudspeakers each include a horn defined by walls of the cabinet. The upper horn is defined by interior side surfaces of top, first side and second side walls of the cabinet and a first interior side surface of the separator wall. The lower horn is defined by interior side surfaces of bottom, first side and second side walls of the cabinet and a second interior side surface of the separator wall. The separator wall is angled about 15 degrees below a horizontal axis for the speaker while the first and second interior side surfaces thereof have oppositely orientated tapers of generally equal magnitude.

Abstract: A loudspeaker for projecting sound over a listening area having a driver and a horn in which the horn has a coupling portion communicating at an interface with an outwardly flaring portion, the horn forming an elongated slot at the interface and being provided with means for controlling the sound energy along the axis of elongation of the slot, namely a slot which is narrower at one end and flares outwardly to the other end, or a plurality of transverse veins dividing the slot and sound channel.

Abstract: A high-frequency constant-directivity horn including a relatively large throat driver and a relatively large throat for receiving sound from the driver, further includes a pair of vanes mounted wholly within the throat, respectively above and below the longitudinal axis in a vertical plane, for effectively dividing the throat into three smaller "pseudo horns" for directing and shaping sound waves from the transducer up to the point of termination of the vanes, beyond which the individual wavefronts mix within and fill a slot in a middle section of the horn, forming a coherent wavefront for passage into a front section of the horn and transmission therefrom, substantially free from wave interference and beaming effects.

Abstract: A multiple driver manifold for coupling four high frequency drivers to a single horn. Two drivers are mounted in a "Y" or "skewed" configuration, and two additional drivers are mounted so as to be directly opposed to one another along a line perpendicular to both the horn throat on-axis direction and the general plane of the "Y" configuration. Sound radiated transverse to the horn on-axis direction by the opposed drivers is "ray-reflected" by a unique ray-reflection summation plug located at the internal hub of the four acoustic paths.