Abstract: A phase plug for an electrodynamic compression driver, including a compression chamber formed by an oscillating diaphragm and a boundary face of a phase plug assembly adjacent to the diaphragm, a singular acoustic exit defined by a termination of the phase plug assembly, one or more passageways which traverse through the phase plug assembly from the compression chamber to terminate at the acoustic exit, and an axis of rotation, defined within an interior of the phase plug assembly, that extends from the boundary face of the phase plug assembly at the compression chamber to the acoustic exit, where at least one of the passageways expands in cross sectional area between the respective entrance at the boundary face of the phase plug assembly, and the termination at the acoustic exit, while traversing through the phase plug, and where at least one of the internal passageways with the expanding cross section is rotated about the axis of rotation.

Abstract: A speaker includes: a diaphragm having a dome shape; a tubular member having the diaphragm disposed inside, and having an inner diameter increasing toward a front; and a phase plug. The phase plug includes: a front surface, a rear surface facing a central portion on a front surface of the diaphragm at a constant interval in parallel, and a side surface connecting the front surface and the rear surface. A front surface of the phase plug is larger than a rear surface of the phase plug as viewed in a front-rear direction of a speaker. At least a part of a side surface of the phase plug has an inclined surface extending outward while extending forward, faces an inner circumferential surface of the tubular member and a front surface of the diaphragm, and directs a sound wave generated from the diaphragm toward an inner circumferential surface of the tubular member.

Abstract: Systems and methods are herein described for a coaxial loudspeaker. The loudspeaker may comprise a compression driver having a first diaphragm assembly including a first magnet, and a first diaphragm coupled to a first voice coil, and a second diaphragm assembly including a second magnet and a second diaphragm coupled to a second voice coil. The compression driver may further comprise a third diaphragm assembly including a third diaphragm coupled to a third voice coil.

Abstract: A compression driver for an omnidirectional loudspeaker includes a motor assembly and a dome diaphragm disposed coaxially above and operably connected to the motor assembly, the diaphragm having a convex surface and a concave surface. The compression driver includes a phasing plug having a top portion and a bottom portion having a concave bottom surface disposed adjacent the convex surface of the diaphragm and defining a compression chamber therebetween. The phasing plug includes a plurality of conduits extending through the bottom portion for sound waves to travel and converging to form an annular exit, the top portion including a plurality of radially expanding channels acoustically connected to the annular exit. Actuation of the diaphragm by the motor assembly generates sound waves within the compression chamber which travel through the annular exit and the radially-expanding channels to create a generally horizontal 360° radiation pattern of the sound waves from the compression driver.

Abstract: A compression driver including an acoustic outlet duct, a magnetic assembly having a permanent magnet and an air gap, a vibrating membrane with a movable coil adapted and configured to move inside the air gap, where the vibrating membrane includes a first face facing a first chamber communicating with the outlet duct, where the first chamber is a compression chamber, a second face opposite to the first face and facing a second chamber communicating with the air gap and opposite to the first chamber, where the compression driver includes at least one acoustic connection duct which puts in communication the second chamber with the acoustic outlet duct.

Abstract: A loudspeaker includes a cabinet, a coaxial transducer assembly, and a waveguide. The coaxial transducer assembly includes a first transducer and a second transducer that is coupled to the first transducer and arranged such that respective motion axes of the transducers are coaxial. The waveguide is coupled to the first transducer and configured to provide an acoustic impedance match between the first transducer and free air. The waveguide includes a first plurality of apertures that enables acoustic energy radiated from a first radiating surface of the second transducer to pass through the waveguide and merge with acoustic energy radiated by the first transducer. The first plurality of apertures extends through an expansion region of the waveguide.

Abstract: The present disclosure provides a speaker module. The speaker module comprises a frame having side walls, a magnetic circuit system and a vibration system housed in the frame. The vibration system comprises a diaphragm fixed on the side wall and a voice coil for driving the diaphragm to vibrate. The magnetic circuit system comprises a magnet and a yoke for accommodating the magnet. The yoke is disposed on the side wall and enclosing a receiving space with the side wall. A sound cavity of the speaker module is formed between the diaphragm and the yoke, the yoke comprises an upper surface adjacent to the diaphragm and a lower surface away from the diaphragm, and the yoke is provided with a plurality of micropores arranged in an array through the upper surface and the lower surface. The gas in the rear sound cavity leaks to the outside of the speaker module.

Abstract: A full-range speaker with phase plate includes a speaker body disposed with a bracket above and a phase plate including a phase plane. The bracket is adapted to the phase panel. The phase panel is fixed above the bracket. The opposite corners of the phase panel are provided with protruding support ribs, and each of the support ribs meets with each other. By adding the phase plate, the phase may be adjusted to prevent standing waves, and the frequency response characteristics of the speaker may be effectively improved, so that the overall frequency response curve of the full-range speaker is improved at 6 kHz-18 kHz, thereby smoothing the overall frequency response curve of the full-range speaker.

Abstract: In at least one embodiment, a dual asymmetric compression driver is provided. The dual asymmetric compression driver includes a first driver assembly and a second driver assembly. The first driver assembly is positioned about a central axis and includes a first annular diaphragm having a first planar section extending at a first clamping distance. The second driver assembly is positioned about the central axis and includes a second annular diaphragm having a second planar section extending at a second clamping distance. The first clamping distance is different from the second clamping distance causing the first asymmetric driver to provide a first audio output in a first frequency range and the second driver assembly to provide a second audio output in a second frequency range.

Abstract: This application provides a combined-type phase plug, and a compression driver and a speaker using same. The combined-type phase plug of this application includes a first phase plug and a second phase plug. The first phase plug includes a cone, a plurality of fins, and a base ring. The plurality of fins is located on an outer surface of the cone. The base ring is located below the cone, and the plurality of fins extends downward to the base ring. The base ring is connected to the plurality of fins but is not connected to the cone. That is, the cone and the base ring are connected only by the plurality of fins. The second phase plug is located under the first phase plug. The second phase plug includes a tapered cone and a base. The tapered cone is located inside the base ring, and a first space is formed between the tapered cone and the base ring. A second space is formed between the tapered cone and the cone, and the second space extends to the first space.

Abstract: A compression driver includes a phasing plug having a base portion with a first side and an opposed second side, and includes a hub portion extending outwardly from the first side along a central axis, the hub portion including an outer surface. The base portion includes a plurality of apertures that extend therethrough from the first side to the second side, the apertures arranged generally circumferentially about the central axis and oriented generally parallel to the outer surface of the hub portion. A diaphragm is disposed adjacent the phasing plug second side, and a compression chamber is defined between the diaphragm and the phasing plug. A housing is positioned on the phasing plug first side, the housing having a central aperture generally aligned with the hub portion and forming an exit of the compression driver, the housing having an inner surface which forms a waveguide with the outer surface of the hub portion.

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: An acoustic transducer may comprise a sound source, a throat connected to the sound source, and a horn connected to the throat. The horn may be arranged on a wall, wherein the throat is designed such that a path of the sound from the sound source to an interface between the throat and the horn is shorter in a region close to the wall than at a region that is remote from the wall.

Abstract: A loudspeaker assembly comprises a casing with a diaphragm loudspeaker mounted in the casing. A phase plug is mounted in the casing adjacent the diaphragm loudspeaker. The phase plug has a central cone with a longitudinal axis extending from an input end adjacent the diaphragm loudspeaker to an output end with its base at the input end tapering to an apex at the output end. A plurality of vanes extend radially outwardly from the central cone with the plurality of vanes being thickest at the input end and progressively thinning toward the output end. Radially outward edges of the plurality of vanes are twisted relative to the longitudinal axis with the degree of twist being progressively greater with increasing proximity to the output end. The plurality of vanes tapers in width along their longitudinal extent from the input end to the output end.

Abstract: A speaker includes a ring-shaped vibrating member fixed to an internal support body at an internal peripheral edge, and a bobbin attached to an external peripheral edge thereof. A voice coil is attached to the bobbin and is located in a magnetic gap. A ring-shaped control member faces a front portion of the vibrating member, and a sound pass space is formed at an external peripheral side of the control member and at an internal peripheral side thereof. When listening to the speaker from a diagonal location, treble sound waves generated from the left side area are perturbed by the control member so as to prevent interference from sound waves generated from bilaterally separated areas, which prevents a decrease of treble sound pressure levels.

Abstract: An acoustical phase plug for use in loudspeakers produces a planar rectangular wavefront, or a wavefront with a desired amount of curvature, from the output aperture of the phase plug device when presented with a planar circular wavefront at the input aperture. The phase plug utilizes a waveguide that equalizes the travel paths from the input aperture to the output aperture. The waveguide essentially eliminates surface discontinuities thereby resulting in the reduction of diffraction of the wavefront travelling through the phase plug device.

Abstract: An acoustic horn arrangement including an acoustic horn, a first sound driver operable to drive the acoustic horn and a second sound driver further operable to drive the acoustic horn. The acoustic horn arrangement also including an interface region where sound from the second sound driver transfers into the acoustic horn to combine with sound from the first sound driver, wherein the interface region is adapted to reduce changes in a beam angle measure of the acoustic horn as a function of frequency.

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 loudspeaker assembly comprises a casing with a diaphragm loudspeaker mounted in the casing. A phase plug is mounted in the casing adjacent the diaphragm loudspeaker. The phase plug has a central cone with a longitudinal axis extending from an input end adjacent the diaphragm loudspeaker to an output end with its base at the input end tapering to an apex at the output end. A plurality of vanes extend radially outwardly from the central cone with the plurality of vanes being thickest at the input end and progressively thinning toward the output end. Radially outward edges of the plurality of vanes are twisted relative to the longitudinal axis with the degree of twist being progressively greater with increasing proximity to the output end. The plurality of vanes tapers in width along their longitudinal extent from the input end to the output end.

Abstract: A loudspeaker driver 100 with new horn throat configuration 120 has a phase plug summation plane radius that is also the effective throat of the driver. The selected plane “D” where the elements of the horn that provide directional information to the wave front are implemented is made part of the geometry of the magnetic return circuit back plate 108. The portion of the back plate that is coincident with the selected plane “D” has a lumen or opening that is made equal to the radius of the circle defined by the phase plug summation plane. The geometry of the back plate's lumen controls projected sound's radiation pattern.

Abstract: A radial waveguide assembly comprises a transducer section and a waveguide section. The transducer section includes first and second cone loudspeakers arranged coaxially and in an opposed relationship. A compression plug having two input surfaces is mounted between diaphragms of the cone loudspeakers. Channels from the first and second cone loudspeakers feed common sound chambers located in a belt around the circular perimeter where they connect to external ports. A radial; folded waveguide has a circular throat which connects to the external ports.

Abstract: A loudspeaker system for the reproduction of acoustic waves of music, sound and speech in a substantially circular horizontal plane. The loudspeaker system includes multiple spherical enclosures, each enclosure housing a pair of transducers, each pair of transducers producing acoustic waves of a predetermined frequency range.

Abstract: A linear speaker assembly including a plurality of speakers in side by side relation within a piece of furniture in such a manner that a horn element, a phase plug and other ancillary speaker structure forms a sound path that communicates from the speakers to the environment and the speaker assembly is partially concealed or camouflaged from the casual viewing of an observer. The phase plug and horn element are elongated and are provided along the entire length of the plurality of speakers which comprise a portion of the linear speaker assembly. The phase plug and horn element visually complement the outer portion of the piece of furniture that the plurality of speakers are disposed within. This permits the piece of furniture or other structure to provide amplified sound from a plurality of speakers in side by side relation in such a manner whereby the speaker assembly is substantially camouflaged or not visible.

Abstract: A phasing plug includes a base portion including an input side, an output side, a plurality of entrances on the input side, a plurality of exits on the output side arranged about a central axis, and a plurality of channels fluidly interconnecting the entrances with the respective exits. Each corresponding entrance, channel and exit establish an acoustical path from the input side to the output side that is non-radial relative to the central axis. Two phasing plugs may be provided in a dual compression driver.

Abstract: For a loudspeaker with a cabinet and a driver cone, an acoustic speaker lens may be positioned on the driver cone. The acoustic speaker lens may include a center post and a plurality of ribs extending radially outward from the center post. The acoustic speaker lens may reduce turbulence in air in front of the loudspeaker, thereby leading to an improved perception of audio reproduction.

Abstract: Disclosed herein is a speaker system unit with a cone type vibration plate, a horn and a diffuser. The horn is disposed such that a small-diameter opening thereof is positioned inward from a front opening of the vibration plate, and an outer surface of the horn is arranged along an inner surface of the vibration plate to form a first acoustic path. The diffuser has a base portion, a front end portion and an outer peripheral surface extending therebetween, and is disposed such that the base portion is positioned inward from a front opening of the horn, opposite the small-diameter opening of the horn. The diffuser has a specific shape such that the outer peripheral surface expands along an inner surface of the horn to form a second acoustic path and then narrows toward the front end portion of the diffuser.

Abstract: An electro-acoustic transducer has an electro-magnetically driven moving dome and a phase plug having a body and a dome-interface surface, with a compression cavity formed between the dome and the dome-interface surface. The phase plug includes at least first and second annular slots beginning at the dome-interface surface and extending a first depth into the body of the phase plug. The first and second slots are separated by a bridge element at the dome-interface surface and joined by a first bridge passage at the first depth beneath the dome-interface surface. The phase plug also includes an exit slot coupling the bridge passage to a throat at a second depth in the body of the phase plug.

Abstract: A phase plug comprises a body having an input side for receiving acoustic waves and an output side for transmitting acoustic waves, the body including a plurality of channels extending from the input side to the output side for propagating acoustic waves through the body. The input side comprises an input surface which includes a plurality of slots constituting entrances for the channels, each slot being arranged in a substantially radial orientation on the input surface about a central axis extending through the input surface. Substantially the entire input surface situated between the slots is concave and substantially part of a sphere or an ellipsoid in shape.

Abstract: A phase plug comprises a body having an input side for receiving acoustic waves and an output side for transmitting acoustic waves, the body including a plurality of channels extending from the input side to the output side for propagating acoustic waves through the body. The input side comprises an input surface which includes a plurality of openings constituting entrances for the channels, the input surface being substantially part of a sphere or an ellipsoid in shape. The areas of the openings vary with radial position on the input surface, the radial position being measured in a direction extending perpendicularly from a central axis extending through the input surface. The variation in the areas is a function of the cosine of an angle subtended at the centre of the sphere or a focus of the ellipsoid between the central axis and the radial position.

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 loudspeaker driver 100 with new horn throat configuration 120 has a phase plug summation plane radius that is also the effective throat of the driver. The selected plane “D” where the elements of the horn that provide directional information to the wave front are implemented is made part of the geometry of the magnetic return circuit back plate 108. The portion of the back plate that is coincident with the selected plane “D” has a lumen or opening that is made equal to the radius of the circle defined by the phase plug summation plane. The geometry of the back plate's lumen controls projected sound's radiation pattern.

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. A plurality of channels formed on the second side of the base portion, each channel extending from the hub portion to a corresponding one of a plurality of apertures extending between the first and second sides, the apertures formed to define lines cutting diagonally across the annular section.

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: It is possible to surely protect the user's ear from a sudden large volume and enable the user to surely and clearly hear a sound as information to be alarmed. In case an incoming call signal is received when the user holds a mobile telephone (1) at the speaking position and listens to a message output from an audio output unit (8), a control unit (17) makes a vibrator (27) generate a vibration as an alarm to call user's attention. At the timing when the user has sufficiently separated the mobile telephone (1) from his/her ear, the control unit (17) makes the audio output unit (8) output a ringtone of large volume. Thus, it is possible to surely protect the user's ear from a sudden large volume. Even when a music composition to notify the receipt of incoming call signal is used as a ringtone, the user can surely and clearly hear the sound as information to be alarmed.

Abstract: In a first aspect, a method (e.g., of operating a gaming device) is provided. The method includes the steps of (i) receiving audio/video content; (ii) associating a plurality of sets of outcome values with the audio/video content; (iii) determining a play session; (iv) determining which of the plurality of sets of outcome values to associate with the audio/video content for a duration of the play session, thereby determining an active set of outcome values; (v) determining a result of a game play during the session; (vi) selecting, based on the result, a value from the active set of outcome values; and (vii) outputting, as an indication of the result, the audio/video content and an indication of the selected value.

Abstract: An improved method and device for controlling cone breakup (divisional modes) in extended range, cone diaphragm type electromechanical acoustical transducers for reproducing an acoustical signal from a corresponding electrical signal is provided. The transducer assembly includes a low mass cone shaped diaphragm, a voice coil former of 30 mm or less in diameter, and a shaped device no wider than the diameter of the voice coil former and extending into the inner volume of the cone but no taller than the height of the outside edge of the cone. This shaped device defines the shape and volume of a small mass of air within the boundary layer of air where molecular adhesion of air molecules to the cone diaphragm surface becomes a significant variable in the performance of the extended range transducer.

Abstract: Sintered elements for use in hazardous areas comprise a first flame path having a first length and a first pore size, and a second flame path having a second length and a second pore size. The second length is greater than the first length and the second pore size is greater than the first pore size. Sounders and loud speakers for use in hazardous areas comprise a housing having a horn and a rear enclosure, a driver assembly, and a sintered element.

Abstract: A planar diaphragm acoustic loudspeaker having a planar diaphragm biased with a high magnetic flux density magnetic circuit which feeds an acoustic waveguide. The apparatus provides high fidelity and efficient acoustic reproduction of high frequency alternating current signals with a minimum of diaphragm resonance and with a substantially flat electrical input impedance versus frequency. The diaphragm has a substantially uniform drive across an acoustically active portion and is held in three dimensional space whereby any mass or diaphragm resonances are controlled and minimized. The acoustic waveguide mates with said diaphragm and ensures a uniform acoustic phase field and an optimal diaphragm acoustic impedance match with atmosphere.

Abstract: A phasing plug includes a base portion including an input side, an output side, a plurality of entrances on the input side, a plurality of exits on the output side arranged about a central axis, and a plurality of channels fluidly interconnecting the entrances with the respective exits. Each corresponding entrance, channel and exit establish an acoustical path from the input side to the output side that is non-radial relative to the central axis. Two phasing plugs may be provided in a dual compression driver.

Abstract: For a loudspeaker with a cabinet and a driver cone, an acoustic speaker lens may be positioned on the driver cone. The acoustic speaker lens may include a center post and a plurality of ribs extending radially outward from the center post. The acoustic speaker lens may reduce turbulence in air in front of the loudspeaker, thereby leading to an improved perception of audio reproduction.

Abstract: A loudspeaker is provided for receiving an electrical signal and transmitting an acoustic signal through a transmission medium. The system includes generally two elements: a coaxial transducer and an acoustic transformer. The coaxial transducer includes a high-frequency driver and a mid-frequency driver that are coaxially arranged. The acoustic transformer is acoustically coupled to the coaxial transducer and includes an initial horn section that expands from a first end to a second end in a direction away from the coaxial transducer. The initial horn section defines a plurality of openings therethrough, such that the initial horn section is acoustically opaque to high-frequency acoustic signals to thereby function as a waveguide for the high-frequency acoustic signals, while it is acoustically transparent to mid-frequency acoustic signals.

Abstract: A planar loudspeaker includes a shell pot, a magnet, a diaphragm, and a face plate. The magnet may be positioned in a cavity in the shell pot. The diaphragm may be coupled with the shell pot to cover an entrance to the cavity. The shell pot may include a conductive path having an inner contact proximate the central axis of the diaphragm, and an outer contact proximate to a perimeter of the diaphragm. The face plate may be coupled with the shell pot so that the diaphragm is positioned between the magnet and the faceplate. The face plate may include an inner terminal and an outer terminal that are aligned to be in direct contact with the respective inner contact and the outer contact of the diaphragm and form an electrical connection there between when the face plate is coupled with the shell pot. The inner and outer terminals may be coupled with a source of electrical signals, such as an audio amplifier.

Abstract: An electro-acoustic transducer has an electro-magnetically driven moving dome and a phase plug having a body and a dome-interface surface, with a compression cavity formed between the dome and the dome-interface surface. The phase plug includes at least first and second annular slots beginning at the dome-interface surface and extending a first depth into the body of the phase plug. The first and second slots are separated by a bridge element at the dome-interface surface and joined by a first bridge passage at the first depth beneath the dome-interface surface. The phase plug also includes an exit slot coupling the bridge passage to a throat at a second depth in the body of the phase plug.

Abstract: A phase plug comprises a body having an input side for receiving acoustic waves and an output side for transmitting acoustic waves, the body including a plurality of channels extending from the input side to the output side for propagating acoustic waves through the body. The input side comprises an input surface which includes a plurality of slots constituting entrances for the channels, each slot being arranged in a substantially radial orientation on the input surface about a central axis extending through the input surface. Substantially the entire input surface situated between the slots is concave and substantially part of a sphere or an ellipsoid in shape.

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: An acoustic transducer includes a frame, voice coil movable along a pole, magnetic structure generating magnetic flux in a gap where the voice coil moves, diaphragm attached to the coil, waveguide extension in front of the pole, inner flexible roll seal connecting the waveguide extension to neck area of the diaphragm, and outer seal connecting outer periphery of the diaphragm to the frame. The inner flexible roll seal seals the gap between the voice coil and the pole, isolating the air in front of the diaphragm from the air behind the diaphragm. The inner seal provides damping of unwanted resonances of the diaphragm. Together, the inner seal and the outer seal do not substantially decrease the piston area of the transducer, and do not substantially affect the transducer's movement. In combination, the inner seal and the waveguide extension tend to increase efficiency and decrease audio distortions of the transducer.

Abstract: A method and a loudspeaker construction (10), in which loudspeaker construction spherical acoustic wave fronts emitted by the diaphragms (12) of speaker elements (11) are transformed into a uniform, planar acoustic wave front. The loudspeaker construction (10) comprises a plane wave channel (20), in the surface (26) of which plane wave channel directed towards the diaphragm (12) there are adjacent sound inlet apertures (24) for transmitting acoustic waves into ducts (23) and, on the opposite side (22) of the plane wave channel, there are outlet apertures (25) for transmitting acoustic waves from the ducts into a horn portion (30). The ducts (23) taper so that the width (B) of the outlet apertures located in a row on the side of the horn portion is less than half the diameter (D) of the diaphragm.

Abstract: An apparatus acoustic loading of a diaphragm is disclosed. The apparatus comprises a rear face having a shape corresponding to a shape of a compression side of the diaphragm, a front face opposite to the rear face along an axis of symmetry, and a plurality of voids formed between the rear face and the front face. The plurality of voids are arranged so that their intersection with rear face forms a plurality of inlets, the plurality of inlets defining a higher compression ratio in the proximity of a voice coil compared to a compression ratio defined in at least a portion of the remaining area of the diaphragm.

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. A plurality of channels formed on the second side of the base portion, each channel extending from the hub portion to a corresponding one of a plurality of apertures extending between the first and second sides, the apertures formed to define lines cutting diagonally across the annular section.

Abstract: A phase plug comprises a body having an input side for receiving acoustic waves and an output side for transmitting acoustic waves, the body including a plurality of channels extending from the input side to the output side for propagating acoustic waves through the body. The input side comprises an input surface which includes a plurality of openings constituting entrances for the channels, the input surface being substantially part of a sphere or an ellipsoid in shape. The areas of the openings vary with radial position on the input surface, the radial position being measured in a direction extending perpendicularly from a central axis extending through the input surface. The variation in the areas is a function of the cosine of an angle subtended at the centre of the sphere or a focus of the ellipsoid between the central axis and the radial position.