Abstract: An acoustic device comprising: an enclosure defining an acoustic port and an acoustic pathway between the acoustic port and a transducer coupled to the enclosure; and an array of attenuators acoustically coupled to the acoustic pathway to absorb ultrasonic acoustic waves.

Abstract: An acoustic lens includes: a plurality of fins each having one end portion located on a side opposite to the loudspeaker on a support surface that extends as convexly curved along a predetermined direction when the acoustic lens is viewed from a lateral side, the plurality of fins being arranged in the predetermined direction at substantially equal intervals and substantially in parallel to one another. When the acoustic lens is viewed from the lateral side, the plurality of fins are substantially identical in length, and an elevation angle of the support surface relative to each of the plurality of fins gradually increases from one side to an other side in the predetermined direction.

Abstract: A compression driver for an omnidirectional loudspeaker having an inverted dome diaphragm, a phasing plug having a top portion facing a convex surface of the inverted dome diaphragm and a plurality of concentric apertures that cooperate with the convex surface of the inverted dome diaphragm. Each aperture has a predetermined radial width and is spaced a predetermined concentric distance from an adjacent aperture converging at an exit of the phasing plug. The compression driver has a dispersion control assembly mounted to the bottom portion of the phasing plug along the central axis.

Abstract: A loudspeaker may include a full-range waveguide for creating a unified wavefront. The waveguide may include a plurality of entrances, which may be positioned at a first axial end. The waveguide may include a mouth disposed at a second axial end opposite the plurality of entrances. A contoured surface extending between the entrance and the mouth defines a cavity within the waveguide. The contoured surface may include a first pair of walls positioned opposite one another and a second pair of walls positioned opposite one another. The waveguide may include at least one integrator disposed in the cavity between two adjacent entrances. Each integrator may extend transversely between the first pair of walls and may taper towards the mouth to form a pointed edge extending between the first pair of walls. A pair of integrator surfaces each include a solid portion and a perforated portion.

Abstract: The present disclosure provides an electronic device, which includes a display module and a speaker, the speaker is placed on the back surface of the display module, and the device includes a mainboard component and a power panel component placed on the back surface of the display module; the speaker is placed below the mainboard component and the power panel component, the speaker includes a speaker body, an inverter tube, a first loudspeaker for producing mediant or bass, a second loudspeaker for producing mediant or treble, a sound producing surface of the first loudspeaker is placed on the surface of the speaker body back to the display module, and a sound producing surface of the second loudspeaker is placed on the lower surface of the speaker body.

Abstract: An acoustic transformer includes at least one outer boundary wall. A plurality of inner walls are disposed within the outer boundary wall. The outer boundary wall and the inner walls define a substantially annular input opening divided by at least some of the inner walls into a plurality of circumferentially-spaced input sections. Each of the input sections has an inner circumferential side and an outer circumferential side. A substantially rectangular output opening is divided by at least some of the inner walls into a plurality of output sections. Each of a plurality of acoustic paths interconnects a respective one of the input sections with a respective one of the output sections. The acoustic paths maybe identical or individually unique in order to change the both the shape of the acoustic wavefront at the output and the energy distribution.

Abstract: An annular diaphragm compression driver for electro-acoustic conversion has an annular diaphragm, which bears a moving coil, and a compression driver housing with a closed housing base. Opposite the housing base is a sound wave routing element having a sound discharge channel. The compression driver also has an annular magnet system unit, which has an annular magnet gap (M) and a compression chamber, adjoining the magnet gap (M), for the annular diaphragm. The open exit end of the sound discharge channel is in slot form and its entry start is annular. The sound path between the compression chamber and the entry start contains an annular collecting space. The collecting space and the sound discharge channel contain a central sound guidance body having a portion which merges to match the slot-like exit end. The sound discharge channel is formed between the sound guidance body and the sound wave routing element.

Abstract: A speaker apparatus selects a path which emits a speaker sound. The speaker apparatus includes a speaker unit for outputting the sound generated from voice data, a body including at least one or more emission paths for guiding and emitting the sound output from the speaker unit, and a member for opening or shutting out at least one emission path.

Abstract: A plurality of sound emitters mounted on a vehicle having a configurable phase of emission and configured such that they focus the beam pattern in a selected direction.

Abstract: In a low frequency transducer system a multi-compression chamber, an inverse horn structure is employed in combination with a resonance-distortion filter chamber. The filter chamber effectively expands the effective enclosure volume at low frequencies and connected to one of the compression chambers filter parasitic resonances and distortion and allowing the system to more efficiently reproduce low frequencies while being able to use smaller diameter transducers and maintaining good system sensitivity. Compression chambers are organized for constant or continuous compression on a section-by-section basis throughout the inverse horn system.

Abstract: A water-proof sound-transmitting membrane 10 includes a polytetrafluoroethylene porous membrane 1 and has a surface density of 1 to 20 g/m2. The polytetrafluoroethylene porous membrane 1 includes a first porous layer 1a, and a second porous layer 1b stacked on and integrated with the first porous layer 1a by a binding force acting between polytetrafluoroethylene matrices.

Abstract: A phasing plug for a compression driver includes a base portion and a hub portion. The base portion includes a first side, a second side, and a plurality of apertures extending between the first and second sides. The hub portion extends from the base portion along an axis. The hub portion includes an outer surface and a plurality of ribs disposed on the outer surface. A plurality of recesses are defined by the outer surface and respective pairs of adjacent ribs. At least one aperture fluidly communicates with at least one of the recesses.

Abstract: A low frequency exponential folded horn enclosure employing a bifurcated horn terminal pathway and a single driver with a bifurcated throat channel, with driver access from the top or bottom of the enclosure. The horizontal “butterfly” throat is located at the rear of the enclosure and expands vertically, and the vertically arranged bifurcated horn terminus exhausts in a mostly forward direction on opposite sides of the back chamber which is reflex-ported; said ports arranged to each exhaust into the channel folds at each respective corner of the terminal horn channel.

Abstract: A loudspeaker having an omnidirectional radiation pattern at high frequencies. The loudspeaker includes an acoustic device that includes an acoustic enclosure; an acoustic driver, mounted in the acoustic enclosure; and a sheet of compliant material with a aperture therethrough, mounted in the enclosure, between the acoustic driver and the environment.

Abstract: In a low frequency transducer system a multi-compression chamber, inverse horn structure is employed in combination with a resonance-distortion filter chamber. The filter chamber effectively expands the effective enclosure volume at low frequencies and connected to one of the compression chambers filter parasitic resonances and distortion and allowing the system to more efficiently reproduce low frequencies while being able to use smaller diameter transducers and maintaining good system sensitivity. Compression chambers are organized for constant or continuous compression on a section-by-section basis throughout the inverse horn system.

Abstract: A sound wave guide structure for a speaker system comprises a sound passage space connecting an inlet opening 11 to an outlet opening 12. The sound passage space branches in plural stages in a range from the inlet opening 11 to the outlet opening 12, thereby forming a plurality of sound wave guide paths extending from the inlet opening 11 to the outlet opening 12.

Abstract: An improved horn for a compression driver which has an interior foam plug for reducing the amplitude of unwanted non-fundamental wave propagation and better control over the sound radiation pattern of the device.

Abstract: A sound-wave path-length correcting structure for a speaker system includes a sound source and a horn. The horn has a sound-wave path-length correcting throat portion. The sound-wave path-length correcting throat portion corrects a sound-wave path-length of a sound wave input from an inlet opening thereof in the sound path, and emits the sound wave from an outlet opening thereof. The sound path is defined by a first side surface with a concave curved surface and a second side surface with a convex curved surface that face each other with a space, and a third side surface and a fourth side surface that face each other with a space. The third side surface and the fourth side surface are formed so that their surfaces gradually widen as the surfaces advance from the inlet opening to the outlet opening of the sound-wave path-length correcting throat portion.

Abstract: An acoustic transformer for transforming sound waves generated by, for example, a round membrane, into a rectangular wave front with reduced interfering resonances is provided in a form of a waveguide with a generally circular entrance and a generally rectangular exit defined by outer walls. The sound waves, arriving from the radiating membrane, are divided geometrically into two flows of sound waves of generally semicircular cross section. Each of the two flows of sound waves is deformed individually into a rectangular shape. Subsequently, the flows of sound waves are brought together once again at an acute angle. The division of the sound flow of circular cross section into two sound flows of semicircular cross section creates two sound flows, which already have a straight side surface. The two sound flows are passed into curved sound guides, which initially have a generally semicircular cross section and then gradually change over into a generally rectangular cross section.

Abstract: A horn assembly is disclosed. The horn assembly includes a shutter than can cooperate with a horn valve. The shutter disposed on an end portion of the horn assembly can help seal the horn assembly and prevent moisture, rain or debris from entering the interior of the horn assembly. In operation, the shutter can be moved to allow the horn to provide a signal. After the horn has completed operation, the shutter can be moved back to its original sealing position.

Abstract: An acoustic waveguide includes an internally hollow primary body provided with an opening for an incoming acoustic radiation and an outlet opening for diffusing the radiation to the outside of said guide. The primary body defines an acoustic flared conduit for propagating the radiation between the inlet opening and the outlet opening. The waveguide further includes a plurality of acoustic discontinuity elements inside the acoustic conduit between the inlet opening and the outlet opening, and which are operative to interfere with the radiation propagating inside the acoustic conduit. The plurality of acoustic discontinuity elements include an array of spaced apart pins transverse to the acoustic conduit.

Abstract: A horn or waveguide public address unit, enabling to adapt the dispersion characteristics of the horn or waveguide. The unit is provided with at least one profiling component (21a, 21b) constituting a removable dispersion shaper, capable of being mounted on the inner wall of the horn (13) or waveguide between the throat (17) and the mouth (19) thereof.

Abstract: A phase plug for optimally matching a drive-unit's diaphragm to the throat of a waveguide is disclosed. Specific embodiments of a circular diaphragm matched to an elliptical waveguide and a circular diaphragm to a rectangular waveguide are disclosed.

Abstract: An improved throat (2) for transmitting acoustic energy from a source driver unit (7) to a feeder section (3) of a directivity controlling acoustic horn is disclosed. The throat (2) comprises: a circular throat entrance (2i) connectable to the source driver unit (7); a rectangular throat exit (2e) connectable to or integral with the feeder section (3); and a circular cross-section to rectangular cross-section transition portion (2a) extending between the throat entrance (2i) and the throat exit (2e). The throat (2) is shaped such that its profiles initially diverge from an axis longitudinal to the throat (14) at the same angle in a direction from the throat entrance (2i) towards the throat exit (2e). Such a throat, when fitted in an appropriate acoustic horn with a source driver unit having a taper matching the aforesaid profile angles, provides a smooth transition for sound waves propagating out from the source driver unit into the horn.

Abstract: The invention provides a speaker unit for low frequency reproduction wherein distortion is reduced and the orientation of a sound image of the lower side frequency region is augmented. To that end, the phase characteristic in an actually used frequency band is made substantially flat. The speaker unit includes a speaker enclosure, a duct formed in the speaker enclosure and having a port thereon, and a speaker mounted in the speaker enclosure. The speaker is formed such that it has a first resonance frequency set higher than a higher side frequency of the actually used frequency band (about 20 Hz to 100 Hz), while the port is formed such that it has a second resonance frequency set lower than a lower side frequency of the used frequency band.

Abstract: A method for displaying horizontally aligned characters on a radial display is disclosed. Each range bin for each scan line is associated with a rectangular grid location to determine the character located in the grid location and the background color and foreground color for the grid location. A font matrix corresponding to the appropriate character is then used to determine if the range bin corresponds to one of the pixels that make up the character or if the range bin corresponds to a background pixel. This determines if the range bin is assigned the foreground color or background color. The method is done for each range bin value and for each scan line. The range bin and scan line information is sent to a display.

Abstract: A loudspeaker horn (11) having a throat end (13) for receiving acoustic power from aligned acoustic power sources (41, 43, 45), an elongated throat (33), and a flared section (17) is provided with grating lobe mitigation fins (27, 29) that extend substantially parallel to the propagation axis of the horn from the throat end toward the mouth end of the horn's flared section. The length of the grating lobe mitigation fins is established in accordance with the degree of suppression of the grating lobes produced by the aligned acoustic power sources that is desired.

Abstract: A directional speaker system includes an enclosure having an inner surface, an outer surface, an open end, and a closed end, a speaker driver directed toward the open end and mounted near the closed end of the enclosure, an in-line phase plug mounted in front of the speaker driver for manipulating the wavefront of sound waves produced by the speaker driver, and a preferably frustoconical shaped wave guide provided between the speaker driver and the open end of the speaker enclosure. A preferably annular space is provided between the enclosure and the wave guide and a plurality of openings are provided between the enclosure at the open end of the enclosure. Out-of-phase sound waves produced by the speaker driver travel into the space and exit the speaker system through the openings.

Abstract: Differential flow vents allow airflow within a vent to be preferential. A flange disposed within a vent introduces non-linearities and causes a preferred direction of airflow into an expanding volume. The differential flow vents are used in conjunction with the natural motion of the loudspeaker cone acting as a pump to cool the loudspeaker cabinet enclosure without having to directly cool the woofer magnet structure. In one embodiment, at least one pair of opposed differential flow vents within the cabinet enclosure provide fresh air to be preferentially circulated to cool the interior of a loudspeaker system. In another embodiment, by providing an odd number of opposed differential flow vents within the cabinet enclosure, positive air circulation also results. By making either the pairs or odd number of differential flow vents to be asymmetrical, dynamic woofer offset is compensated.

Abstract: The present invention provides a loudspeaker capable of matching a sound image and a picture image on a screen of an image reproducer with each other in simple construction and a simple method of installation. The loudspeaker is located above the image reproducer in the vicinity thereof and so constructed as to reproduce a center channel signal in a multichannel sound signal for a movie or the like as a principal object, which comprises a main speaker unit, particular band preventing means for suppressing the level of a particular band in a band of not less than approximately 4 kHz of the main speaker unit, a sub-speaker unit, particular band passing means connected to the sub-speaker unit for passing only the particular band, and a dispersing device located on a front surface of the sub-speaker unit and so constructed that a reproduced sound radiated from the sub-speaker unit is mainly composed of a diffused sound.

Abstract: Method and apparatus applied to loudspeakers of the type having an electrically driven diaphragm in an acoustic housing to reduce distortion from two sources. 1. Loss of high frequencies when sound from different regions of the diaphragm travel paths of different lengths and neutralize each other when they meet out of phase. 2. Noise generated primarily by the central region of the diaphragm when driven at high power. A compensating or phase plug is suspended axially within the housing adjacent the central region of the diaphragm. The plug, in cooperation with the walls of the housing, directs the sound through paths of uniform length to reduce loss of high frequencies. The plug has a sound absorbing inner portion adjacent the central portion of the diaphragm for absorbing the noise generated by the central portion at high power.

Abstract: Aqueous solutions of N-methylol compounds of carboxamides, urethanes, ureas and aminotriazines or of N-methylol ethers of these compounds that are suitable for finishing cellulose-containing textile materials are prepared by reaction of compounds having one or more N--H groups in aqueous solution with formaldehyde and, in the case of N-methylol ethers, with an alcohol by adding boron trifluoride, a boron trifluoride addition compound or tetrafluoroboric acid or a salt thereof to the aqueous solutions during or immediately after the reaction.

Abstract: A jet engine test cell capable of dissipating infrasound. The test cell includes an engine test section, an augmentor and an exhaust stack having a structure near its open end for dissipating infrasound.

Abstract: The invention concerns a loudspeaker with a diaphragm which is electromagnetically induced to vibrate and is made of a central dome-shaped part and a conical part surrounding the latter, and a phase-correction device, consisting of a cone fixed in the housing with its base side matching the shape of the diaphragm and of two rings surrounding the cone concentrically, between which there are sound paths from the diaphragm into the sound outlet area. The object of the invention is to smooth out the transmission characteristic of the loudspeaker named initially and to enlarge the transmissible frequency band with simple means.

Abstract: An electroacoustical transducing system for exchanging pressure wave energy with a medium that propagates pressure waves includes an electroacoustical transducer having a vibratile surface. At least one low-loss pressure waveguide has one end adjacent to the vibratile surface and the other end adjacent to the medium. At least one acoustic immittance element is imposed in the length of the waveguide dimensioned and positioned to alter the transfer characteristic of the waveguide between the vibratile surface and the medium at the other end.

Abstract: An apparatus (32) for modifying the percussive sound emanating from a drum (10) includes a hollow skirt (34) having a first end (36) and a second end (38) that define openings (40) and (42) that are in opposition and communication with each other. The skirt (34) is generally configured to be conical or quasi-conical in shape, the first end (36) forming the base of the conical shape and the second end (38) forming the vertex. The opening (42) is large enough for a stand (24) upon which the drum (10) is mounted to pass through. The material or materials selected for the skirt (34) depends upon the desired tonal results of the apparatus.

Abstract: The present invention involves a moving-coil electrodynamic electroacoustical transducer, comprising a disk made of a hard, nonmagnetic material (12), which is superimposed on the diaphragm (11) and has openings for the output of sound, a power-factor-improvement device/super charger (13) made of a nonmagnetic material which is placed in the concavity of the diaphragm (11) and which has annular, concentric ducts (13') having a conical shape, and a cover (14) made of a nonmagnetic material serving as the lid in both configurations of the transducer, the said cover being applied to the body facing the concavity of the said diaphragm in a direct-radiation transducer, while it is applied to the body facing the convexity of the said magnetic disk (12) in an indirect-radiation transducer.

Abstract: A wave guide fitted at the output of a loudspeaker, in front of the membrane or in front of the orifice of a compression chamber, along the axis of the transducer being considered, and comprising a conduit which expands from its input to its output. The area of the output orifice of the wave guide is planar and oblong, that its conduit comprises a passage between the input orifice and the output area, adapted to guide the waves along a general direction from which the shortest paths allowed in the one or more passages are all of lengths which are practically identical from the input orifice to the output orifice of the conduit. The invention is for use in providing sound to large areas.

Abstract: An improved compression driver has a phasing plug with air passages coupling the compression region of the loudspeaker to the throat of the loudspeaker. An auxiliary air passage combines with a plurality of inner primary passages, which may be of the annular, radial or saltshaker form, to couple variations in pressure from the region around the voice coil to the throat of the speaker.

Abstract: A loudspeaker including a diaphragm for generating sound waves, the diaphragm being comprised of a peripheral conical portion adjacent to and surrounding a central domed portion, a flared horn adjacent to the diaphragm for receiving and projecting the sound waves into an acoustical space, a phasing plug intermediate the diaphragm and the horn defining sound pathways for impedance matching of the diaphragm and the horn. A plurality of sound channels extend through the phasing plug from the peripheral conical portion and the central domed portion of the diaphragm to the horn. The plurality of sound channels provide time compensated paths of equal length for the sound waves generated at both the peripheral conical portion and the central domed portion of the diaphragm.

Abstract: A loudspeaker system which comprises a loudspeaker unit for radiating a first sound, a horn unit having a throat coupled to the back of the loudspeaker for radiating a second sound, and an acoustic filter provided in the horn for causing an acoustic impedance of the horn unit to be discontinuous. When the minimum frequency of cyclic dales of the sound pressure observed in the characteristic curves of a sound pressure of a composite of the first and second sounds as a result of a phase delay brought about by the length of the horn unit is expressed by fd, a primary harmonic resonance can be produced between the loudspeaker unit and the acoustic filter which is similar to that produced by a straight acoustic tube having its opposite ends closed, thereby to render the frequency of the primary resonance to be generally equal to the frequency fd.

Abstract: An improved adaptor for coupling a plurality of compression drivers to the throat of a common horn is disclosed. The improved adaptor of the present invention includes a passage coupled to each of the plurality of compression drivers, the passages extending forwardly toward the horn. A longitudinally extending central member is mounted within the horn flare, extending along its central axis and tapering forwardly. The surfaces of the horn flare and the central member define an annular region between the side walls of the horn flare and the central member. The passages for each of the compression drivers are connected with this annular region. The adaptor therefore comprises a manifold whose passages operate into three symmetrical sectors of the annular passage formed by the insertion of the central member into the horn flare.

Abstract: An acoustical impedance inducing device is created for axial insertion into the longitudinal air column of a wind musical instrument. The device includes a first annular band of first predetermined thickness and a second annular band of approximately twice the thickness of the first band. A first web interconnects the first and second bands and maintains the bands at a predetermined axial spacing. The web is formed of strips diagonally disposed between the first and second bands and defining a triangle shaped aperture between adjacent bands, with the base of the triangle being colinear with an edge of one of the first and second bands. A third annular band, twice the thickness of the second, may be separated from the second band by a second web; or the device may be placed in a tubular portion of the instrument at a location where an end of the tubular portion is spaced from the second band by the axial width of the web.

Abstract: A horn type loudspeaker comprises a drive unit, which is largely the same in structure and features as the conventional drive unit, and a horn member specially designed to effectively minimize its size and weight. Said horn member comprises a hollow disk mounting case with its inner periphery corresponding to a fixing plate of the drive unit engaged thereon, a reflection cover with a tip on its inner surface pointing downwardly towards the central portion of a hole located at the fixing plate connected to the upper inner surface of said mounting case with a plurality of discharge openings uniformly located around the outer periphery so as to overcome the restriction of the standard sizes and have a size and weight small and light enough for miniature applications such as for pocket-size security alarms.

Abstract: A sound projection system for use in diffusing sound of a frequency ranging from 160 Hz up to 5 KHz over a relatively long distance with a substantially constant distribution of the sound over a wide diffusion angle, whereby the quality and intensity of the sound transmitted by the system remain substantially constant for a listener even if this person is substantially offset from the general direction and orientation of the projection system. The system which is advantageously compact in size, comprises a cabinet defining an enclosure in which a loudspeaker is mounted. An acoustic channel of rectangular cross-section is connected to the cabinet in alignment with the loudspeaker.

Abstract: A speaker system including a frusto-conical diaphragm, and a phase plug mounted within the volume formed by the diaphragm, the phase plug including a pair of substantially diametric open slots extending across the diaphragm and through the phase plug, with each of the slots having substantially rectangular cross sections transverse to the axis of the diaphragm.

Abstract: An ultrasonic horn assembly includes a horn with a bore tapering from a throat out to a mouth. An ultrasonic transducer is mounted in the throat of the horn. A beam narrowing insert includes a headpiece which tapers smoothly from a larger diameter base to a smaller diameter top. A stem projects from the base so that the base and stem define an annular shoulder which faces the transducer. A blind bore in the stem terminates at a flat bottom surface which faces the transducer. A ring receives the transducer and webs project inwardly therefrom to support the headpiece in spaced relationship to the transducer.

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: An accessory for mounting on the receiver of a personal paging system. The receiver is normally worn below ear level and the accessory increases the sound of the paging signals reaching ear level.

Abstract: A sound projection system comprising means defining a longitudinally extending acoustic channel which is acoustically open at a front end of the channel and acoustically closed at a rear end and at sides of the channel, a loudspeaker having a cone diaphragm operating into the channel at the rear end of the channel, and a longitudinally extending member mounted within the channel directly in front of, and in alignment with, the loudspeaker so as to restrict the free space within the channel, the cross-sectional area of said member varying along its length.