Abstract: A loudspeaker includes a box-form structure made from stiff lightweight sheet material to define a plurality of faces, at least one face of the structure forming a panel-form bending wave acoustic radiator, and an electro-acoustic vibration transducer coupled thereto to apply bending wave energy to the radiator to cause it to radiate an acoustic output when an input signal is applied to the transducer. The box-form structure is collapsible, so that the box-form structure can be stored and transported in a flat form and erected as a box when required as a loudspeaker.

Abstract: A speaker module includes a first diaphragm and a second diaphragm acoustically coupled with each other as a part of a wall forming a hermetic space with a panel. A light emitting section emits light to the panel, and the panel transmits the light to a side of the second diaphragm. The speaker module is configured to emit sound and light.

Abstract: A speaker collective substrate with component insertion hole sections and electrode sections has a plurality of speaker forming areas. An electrical speaker section, which comprises a magnetic circuit section and a vibration section, is inserted into each of the component insertion hole sections. Then, a collective lid, in which a plurality of lids have been formed for sealing the electrical speaker sections, is attached onto the speaker collective substrate. After that, the speaker collective substrate and the collective lid are divided into individual speaker forming areas along partition lines extending in the directions of the X and Y axes to form individual dynamic speakers. Thus, it is possible to mass-produce dynamic speakers with uniform quality through a collectively manufacturing process.

Abstract: A loudspeaker system designed for ceiling installation. The system includes a woofer, a midrange speaker and a tweeter commonly supported on a rotatable support member which in turn is supported on and is rotatable with respect to an annular rim that is designed to be fixed about an opening in the ceiling. The woofer is aligned at one acute angle and the midrange speaker and tweeter at another acute angle to the annular rim. The mid range speaker and tweeter are partially segregated from the woofer by a baffle.

Abstract: A case is provided for mounting an information equipment and a frame of the compound sound generator is set in the case. A speaker and receiver are provided in the frame. A first back chamber is formed in the speaker and a second back chamber is formed in the receiver. A baffle is formed integrally with the frame so as to separate the first and second back chambers from each other.

Abstract: A flush mountable ceiling speaker (10) with individual coaxial waveguides (20, 22) for both the lower and high-frequency transducers (11, 12). The lower frequency radiation is combined with the sonic energy radiated by the high-frequency transducer (12) and shaped by the high-frequency waveguide (20) to create a coherent, uniformly controlled coverage pattern. The loudspeaker (10) creates a well defined sound dispersion pattern over a relatively large bandwidth, resulting in increased vocal intelligibility and more accurate reproduction of music at relatively great distances from the loudspeaker, as is particularly useful in association with high ceiling installations.

Abstract: A sound reproducing apparatus includes a display unit, a board 22, a diaphragm panel 23, and an electroacoustic transducer 26. The display unit displays an image on a display surface. The board 22 is composed of a material which transmits visible light and arranged such that a first space is provided between the display surface of the display unit and the board 22. The diaphragm panel 23 is composed of a material which transmits visible light and arranged on the opposite side of the board 22 from the display unit such that a second space is provided between the board 22 and the diaphragm panel 23. The electroacoustic transducer 26 emits sound into the second space.

Abstract: A speaker system includes a display panel for displaying an image; a transparent panel provided such that the image displayed in the display panel is viewed through the transparent panel; an electric-mechanical-acoustic-transducer having a diaphragm for outputting a sound by vibrating the diaphragm in accordance with an electric signal; and an acoustic signal transfer member for transferring the sound output from the electric-mechanical-acoustic-transducer to a space provided between the display panel and the transparent panel. The transparent panel is allowed to be vibrated by the sound transferred to the space from the electric-mechanical-acoustic-transducer via the acoustic signal transfer member.

Abstract: A small-sized speaker system having a very excellent bass-range reproduction capability includes a sound radiation component for guiding acoustic waves radiated from the speaker units to a free space by causing a larger degree of air compression and expansion than in the case where acoustic waves are directly radiated to the free space with the speaker units mounted in corresponding enclosures of the same shape as the speaker units. The speaker system has 20% or more lower f0 than in the case where acoustic waves are directly radiated to the free space with the speaker units mounted in corresponding enclosures of the same shape as the speaker units.

Abstract: The loudspeaker and method provide a driver of a loudspeaker that is movable parallel to an axis of movement through a center of the driver to produce sound waves. The driver is aligned with the driver plane orthogonal to the axis of movement. The driver plane is at a non-zero acute angle to a support plane. A reflector is mounted facing a diaphragm of the driver for reflecting sound waves from the driver. The reflector is configured relative to the driver such that reflected sound energy is greatest in a selected direction from a front of the reflector and the driver, and diminishes a progressively larger angle from the selected direction. The selected direction diverges from the driver plane.

Abstract: A vibration reducing apparatus comprising, a baffle subject to vibration, a first electroacoustical transducer characterized by a first mass seated in the baffle, a second electromechanical transducer mechanically connected to said first transducer or said baffle in the vicinity of the periphery of the first transducer. The rear sides of the diaphragms of the first and the second transducer are not connected to the listening area. The first transducer and the second transducer are constructed and arranged to receive a common electrical signal so that the movable element in the first transducer and the movable element in the second transducer move in phase opposition in response to the common electrical signal to significantly reduce the vibrating force imparted to the baffle.

Abstract: A loudspeaker comprising a moving coil and a membrane fastened to a chassis, where the membrane is divided into a concentrically disposed inner membrane part and a concentrically disposed outer membrane part, whereby a meeting area is defined between the inner membrane part and the outer membrane part, the inner membrane part being fastened to an inner moving coil and the outer membrane part being fastened to an outer moving coil.

Abstract: A coaxial speaker assembly (10) with reduced sound distortion, sound time delay, and polar response distortion. The coaxial speaker assembly (10) includes a high-frequency speaker system (16) mounted coaxially with and fitting within a lower-frequency speaker system (14). A baffle (50) is secured to a diaphragm (48) of the high-frequency speaker system (16). A step-down ledge (52) is circumferentially positioned adjacent to the baffle (50) and extends outwardly therefrom. A portion of the sound waves emanating from the high-frequency diaphragm (48) are reflected off the step-down ledge (52).

Abstract: The present invention discloses an improved single magnetic circuit dual output speaker, comprising a support retainer with an expanded opening at its front end, a bridge disposed across the opening, a magnetic circuit wound and fixed inwardly in the middle of the bridge, a vibrating space disposed on each of both sides of the magnetic circuit, a first voice coil disposed in the vibrating space on one side of the magnetic circuit, a second voice coil disposed in the vibrating space on the other side of the magnetic circuit, a first diaphragm disposed on the expanded opening of the support retainer and having its internal diameter stuck with the first voice coil, a second diaphragm disposed on the expanded opening of the support retainer and having its internal diameter stuck with the second voice coil, and a damper disposed at the back of the support retainer and stuck with the first voice coil, such that the magnetic circuit is mounted at the front of the support retainer by the bridge to provide the dual ou

Abstract: This invention discloses a multi-channel audio center speaker device that has a low-frequency sound box working together with a mid-frequency sound box each on both sides, and the low-frequency sound box works with a high-frequency sound box having a forward sound direction and a mid-frequency sound box having a backward sound direction, and both sound boxes are tilted up to an appropriate angle such that after the sound frequencies are mixed, the audio image provided by the sound frequency of the mixed sound is extended backward through the mid/high frequency speaker, and then the image at the back is reflected to the audience in the front, such that the position of placing the center sound box becomes more flexible, and produces a sound together with the simulated video screen at the back. In the meantime, the present invention can reduce or eliminate the impact of the sound being acted directly on the audience to prevent uneasiness and broaden the range of the multi-channel audio sound.

Abstract: A loudspeaker having a back plate, a driver attached to the back plate, the driver being responsive to an electrical signal, an enhancer having a neck and a mouth, the neck attached to the driver and movable in accordance with the movement of the driver, a thin film membrane, the membrane attached to the enhancer, the membrane stretched over the frame, a frame for supporting the membrane and maintaining it in a taut state, and a rubber type adhesive for dampening the membrane resonances and for adhering the membrane to the frame. Clarity of sound can be further improved by including a plurality of sound breathers in the back plate of the speaker. For improved sound radiation capability, the size and the shape of the enhancer can be modified in various ways, including a frustoconical, parabolic, or bell-shaped enhancer.

Abstract: Loudspeaker mounting apparatus that permits mounting of a loudspeaker at an angle to a mounting surface. In one embodiment the apparatus comprises an assembly that includes a frame member that is flush mountable in a cutout in the mounting surface. The frame member includes an angled flange that is employed for the mounting of a cooperative baffle. The front of the baffle is recessed behind the mounting surface to permit a flush speaker installation. The baffle mounts to the angled flange of the frame member in one of two possible predetermined orientiations so as to disperse sound around a centerline that is either oriented normal to the mounting surface or at a predetermined angle from normal corresponding to the degree of angle incorporated into the frame and baffle assembly.

Abstract: An embedded multimedia speaker structure includes a five-facet housing having a same dimension as that of a 5-and-¼-inch disk drive; a recess disposed at a bottom center portion of the housing; a bass speaker disposed at the recess and having a bell thereof facing downward; a circuit board having play function disposed at an rear end of an interior of the housing and for controlling sounds; a panel enclosing a front end of the housing, and having a speaker provided at two sides thereof, respectively; and two sound guide tubes having an end thereof connected to a rear end of the speakers, respectively, and the other end thereof arranged to an exterior of the housing, respectively. Using the aforesaid structure, a multimedia speaker is assembled for disposing within a 5-and-¼-inch disk drive housing.

Abstract: A loudspeaker system, which has the ability to create a homogeneous sound over large distances, comprising at least one line-source of acoustical radiation, each comprising three or more essentially identical speaker-units arranged adjacent to each other at a center-to-center spacing D1, and at least one elongated high frequency transducer arranged in parallel with said line source(s), said elongated high frequency transducer(s) having an essentially continuous radiating surface along the axis of elongation. Where the crossover frequency FCR and the distance D1, for said line-source(s), is set according to new design criteria, taking into account the frequency response from said speaker units in said line-sources and the optimal performance for a line-source. A method is also included, by which a homogeneous sound over large distances can be accomplished.

Abstract: Headphones with a multichannel guiding mechanism having different channel speakers positioned within each of earphones and separate sound-guiding chambers for receiving the different channel speakers. In taking the acoustics into account, the separate sound chambers are installed within the earphones according to the sound effect of different channel speakers. An inner and an outer tube are installed within the first sound chamber. The inner tube defines a treble area in the middle of the front main speaker while the outer tube defines a bass area around the treble area whereby the first sound chamber has a tube-in-tube configuration. Accordingly, a clear positioning of the acoustic field is achieved by different installation position of the speakers within the earphones. In addition, the interference of sound waves is avoided and the reproduction of original sound is achieved.

Abstract: A loudspeaker includes an assembly of at least two bending wave panel-form acoustic members each having a set of modes which are distributed in frequency. The parameters of at least two of the acoustic members are selected so that the modal distributions of each acoustic member are substantially different. The arrangement is such that the modal distributions of the assembly of acoustic members are interleaved constructively in frequency. A transducer applies bending wave energy to the acoustic members to cause them to resonate to produce an acoustic output. A method of making such a loudspeaker is also provided.

Abstract: A speaker capable to playback in wide frequency range by means of reducing peak values of amplitude of resonance frequencies in frequency characteristics is provided by means of differing a radius of curvature R1 of an inner diaphragm 10a and a radius of curvature R2 of an outer diaphragm 10b to differ resonance frequencies of the inner diaphragm 10a and the outer diaphragm 10b. Furthermore, by means of equalizing an area S1 of the inner diaphragm 10a and an area S2 of the outer diaphragm 10b, sound pressure levels of the inner and outer diaphragms 10a, 10b are equalized with each other.

Abstract: An acoustical transducer enclosure has an acoustic lever acoustically coupled to an electro-acoustical transducer so as to force all radiated sound through the lever.

Abstract: In a speaker device including a plurality of speakers outputting different frequency bands, for a listener listening to sound from the speaker device, a first emitting direction of a first speaker emitting a high frequency band is oriented toward the listener more than a second emitting direction of a second speaker emitting a low frequency band.

Abstract: An elliptical speaker system is provided for in-wall/in-ceiling mounting. The speaker system comprises an elliptical speaker frame or bracket defining a speaker front plane having a generally arcuate inner surface. First and second speaker components are mounted within the speaker frame, on opposing sides of the speaker inner surface. At least one of the speaker components may be translatable within the speaker frame.

Abstract: A loudspeaker device includes left and right channel loudspeaker units which are disposed on left and right sides in close proximity to each other, and a partition member projecting forwardly in the direction of propagation of sound from the loudspeaker units by a predetermined distance from a position between the loudspeaker units on a plane of a baffle on which the loudspeaker units are mounted.

Abstract: A loudspeaker for vehicles having cabins, the loudspeaker including a diaphragm including a first, planar portion for radiating acoustic energy and a second, planar portion for transmitting vibrational energy from a voice coil driver to the first portion. The first portion is incorporated into an inner surface of the vehicle's cabin. The second portion extends from the first portion to a location outside of the cabin, where the voice coil driver is located.

Abstract: An audio array for receiving or generating audio signals. The audio array includes first, second and third audio elements and first second and third structures. Each of the first second and third structures are right triangles. The first second and third audio elements are each secured to a respective one of the first, second and third structures and the first, second and third structures are positioned to extend at a substantially 90° angle to each other. The first second and third audio elements are positioned in a substantially central location of the first second and third structures. The first second and third audio elements are all either speakers or microphones. The first, second and third structures are all retained within a comprising a housing.

Abstract: A bandpass loudspeaker enclosure system including at least one electro-acoustic transducer with a vibratable diaphragm having a first acoustical coupling surface and a second acoustical coupling surface, and at least one differential area passive radiator with three separate acoustical coupling surface areas. The first acoustical coupling surface of the vibratable diaphragm is substantially air coupled through a first enclosure volume to a first of the three separate acoustical coupling surface areas of the at least one differential area passive radiator. A second of the three separate acoustical coupling surface areas of the at least one differential area passive radiator is substantially air coupled through a second chamber to the external environment through a restricted acoustic opening or passive acoustic radiator of predetermined characteristics.

Abstract: A speaker structure having a simple configuration while maintaining good sound quality is disclosed. The speaker structure comprises a first speaker (20) having a first vibration plate (21), a first frame (22) for fixing the perimeter of the first vibration plate and a first magnetic circuit (24) for converting a signal into the vibration of the first vibration plate, a second speaker (30) having a second vibration plate (31), a second frame (32) for fixing the perimeter of the second vibration plate and a second magnetic circuit (34) for converting a signal into the vibration of the second vibration plate, and a fixing unit (50) for fixing the first magnetic circuit and the second magnetic circuit at their backs.

Abstract: The present invention relates to a compound loudspeaker. In the loudspeaker, the L.F. drive unit has a curved flexible diaphragm whose shape is determined such that it optimally controls the directivity of the compound loudspeaker to produce matched directivity of the L.F. and H.F. drive units. The L.F. diaphragm drive unit radiates sound by the controlled flexure of its diaphragm and thus, eliminates the need for a flexible rolling seal at the edge of the diaphragm. This allows for a continuous smooth surface to exist between the H.F. drive unit and the exterior of the loudspeaker, thereby greatly improving its radiation characteristics.

Abstract: A coincident source stereo speaker in accordance with the present invention includes a high-frequency component (tweeter) and a low-frequency component (woofer) that are separated by a sound channel. The tweeter emits a first sound pattern directly outward from the speaker, with the sound pattern having a corresponding high frequency center axis. The sound channel is located between the tweeter and woofer and is symmetrically oriented around the high-frequency component. The woofer emits a second sound pattern into the sound channel for re-direction out of the speaker. With this configuration, the second sound pattern has an effective low frequency center axis that is coincident with the high frequency center axis. As a result, the tweeter and woofer exhibit co-axial performance characteristics, even though they are not physically located co-axially.

Abstract: The present invention relates to an electro-acoustic transducer suitable for applications within mobile communication equipment and hearing aids. The transducer comprises two diaphragms positioned on opposite sides of a magnetic circuit having two magnetic gaps. When used as a microphone the transducer is substantially insensitive to vibrations, and when used as a speaker the transducer generates only very low vibration levels. The magnetic circuit has a number of advantages compared to conventional transducers with circular magnetic. The transducer can be made lightweight and with very compact dimensions compared to conventional designs. In a preferred embodiment the diaphragms are rectangular. The transducer may additionally be used as a vibration generator for silent alarm signals.

Abstract: Disclosed is a multi-function actuator comprising: a case having an internal space; a vibrating coil installed in the case for generating vibration; a diaphragm for generating sound with an outer end being fixed to the upper end of the case; a voice coil fixedly installed in the bottom of the diaphragm for generating sound according to a sound source and having an notch filter; a vertically magnetized magnet; an upper plated attached to the magnet for constituting a magnetic circuit; a yoke for constituting the magnetic circuit together with the magnet; a weight for constituting a vibrator body together with the magnet, the upper plate and the yoke; and a suspension spring for supporting the vibrator body. In generating sound, sound quality is improved without influencing sound while vibration is reduced.

Abstract: A dual diaphragm speaker comprising first and second diaphragms operating in accordance with the piezoelectric effect, the diaphragms being arranged to be driven in opposite phase with respect to one another so as to cancel out non-linearities. The speaker is made transparent and mounted over the display panel of a mobile telephone.

Abstract: A speaker unit includes a woofer having a diaphragm with an ellipse shape sound emitting opening, and a separate speaker having an ellipse shape diaphragm with an area smaller than that of the diaphragm of the woofer, located in front of the diaphragm of the woofer, attached to a center axis of the ellipse shape of the woofer coincident with that of the ellipse shape of the separate speaker, and emitting a sound higher in frequency than that of the woofer.

Abstract: The invention relates to a loudspeaker system. The loudspeaker system respectively includes first and second satellite speaker having a housings supporting a high frequency driver and a middle frequency driver. Each housing forms a complete enclosure with a single opening and the middle frequency driver includes a magnet and a cone. The middle frequency drivers are respectively mounted within the single openings of the housings such the middle frequency drivers seal the interior of the housings from an external environment and the magnets are directed away from the interior of the housings. The high frequency drivers are mounted to the housings for movement in a plurality of planes. The system further includes a subwoofer having a subwoofer housing in which at least one low frequency driver is mounted. The invention further relates to the specific loudspeakers forming the present system.

Abstract: A compound driver acoustic transducer. A frame supports a motion generator to one side of two diaphragms. An intermediate diaphragm is continuous and is driven by the motion generator. The intermediate diaphragm forms a closed volume with a solid portion of the frame that opens into a central opening through the other, open diaphragm. An axially rigid coupling connects the two diaphragms so they operate in unison.

Abstract: A compound loudspeaker drive unit comprising a first drive unit and a second drive unit arranged co-axial with respect to the center axis of the loudspeaker, and each drive unit comprises permanent magnet means and pole piece means together forming a magnetic circuit with a pole gap for exciting a voice coil assembly, each pole gap providing magnetic field directed radially with respect to a center axis of the loudspeaker. At least one of the permanent magnet means has a radially extending magnetization direction with respect to said center axis of the loudspeaker and the acoustic centers of said drive units substantially coincide.

Abstract: This invention provides a system enabling the assembly and suspension of a plurality of line array loudspeakers where the splay angle between the adjacent speakers can be easily adjusted and rigidly maintained. This line array system utilizes rigging frames allowing for the coupling and supporting of the loudspeakers forming and rigidly maintaining a curvature in the line speaker array.

Abstract: A speaker having a tweeter and a woofer together is disclosed. The tweeter can be selectively chosen to combine with the woofer or not, such that a user will have much more choices when mount the speaker. That is, the user is able to decide his/her own style of speaker according to where the user wants to locate the speaker, which increase the variety of decoration and also reduces the volume of the speaker.

Abstract: A direction adjusting arrangement for a tweeter mainly includes a round sleeve screwed to a base mounted at a center of a woofer of a loudspeaker and a ball portion provided at a rear end of the tweeter. The sleeve is formed at a lower inner end with a bowl-shaped socket into which the ball portion is movably received. A curved slide way is provided in the socket extended by a predetermined length from a top of the sleeve toward a bottom center of the socket. A projection is provided at middle point of one side of an outer wall surface of the ball portion to movably extend into the slide way. The ball portion could be turned in the socket with the projection guided by the slide way and be pivotally turned in the socket about the projection, so that the tweeter could be adjusted in its angular position relative to the woofer to face different directions.

Abstract: A loudspeaker includes a compresion chamber, a first electroacoustic transducer and a horn. The first electroacoustic transducer is disposed inside the compression chamber. The horn is mechanically and acoustically coupled to the first electroacoustic transducer. The loudspeaker also includes a second electroacoustic transducer. The second electroacoustic transducer is disposed outside the compression chamber. The second electroacoustic transducer is mechanically and acoustically coupled to the horn.

Abstract: A dual-cone loudspeaker includes a primary speaker cone and an axially displaced secondary speaker cone mounted to the back of a magnet structure. A rigid link causes both cones to move in unison. The rigid link includes an open support structure with equiangularly extending spokes that form a central hub. A ring circumscribes the spokes and ataches to the first speaker cone. A rigid element connects to the spokes and the secondary speaker cone so the primary and secondary speaker cones move in unison and improve the bass response for the loudspeaker. The rigid coupling device is also adapted to support a high frequency radiator to extend the overall loudspeaker frequency response into higher frequencies.

Abstract: A surround sound headphones for enhancing a wearer's listening experience by providing a surround sound speaker configuration therein. The surround sound headphones includes a headband for wear on a user's head and a pair of earpieces coupled to the headband. Each of the earpieces has an open inner face which defines a cavity in the respective earpiece. Each earpiece may also have a generally circular shaped fabric covered shield covering the open inner face of the respective earpiece. The inner face of each of the earpieces has a center extent extending into the cavity of the respective earpiece. The center extent has a plurality of side faces each having at least one speaker mounted thereto.

Abstract: Planar magnetic acoustic transducer diaphragms are formed from an electrical non-conducting membrane and metallic layer laminate by selectively removing portions of the metallic layer to create at least one electrical conductor circuit pattern and at least one passive metallic area both of which are of a predetermined size and configuration to balance modal behavior of the diaphragms when in use.

Abstract: A speaker apparatus, in which a middle-high frequency speaker is disposed forward of a low frequency speaker. First and second sound guiding member are disposed in front of the low frequency speaker and middle-high frequency speaker improving low sound while reducing noise and distortion. The speaker includes a yoke having a path arranged at rear side of a woofer with the first sound guiding member disposed in the yoke for guiding sound discharged through the path. A tweeter is disposed at the front end of the first sound guiding member. A partition wall is disposed at the edge of the tweeter for separating middle-high frequency sound from low sound radiated from the woofer, and the second sound guiding member is disposed at the central portion of the tweeter.

Abstract: This invention outlines several applications of piezoelectric vibrators to produce quality flat panel speakers in passenger cabin applications. A system consisting of an audio amplifier and transformer is used to drive the piezo speaker. The electronics are packaged so that they fit in small modules that can be attached to a cabin structure to produce a speaker. The invention includes a variety of flat panel speaker designs, including one in which the existing structure is converted into a speaker, and thin membrane and or panels that are fitted with piezoelectric elements. A system consisting of cabin quieting and flat panel speakers is also discussed where the mid and high frequency audio is produced by panel speakers and the low frequency audio is produced from dynamic loudspeakers. The cabin systems discussed in this patent are applicable to automobiles, aircraft, trucks and buses.

Abstract: A bandpass loudspeaker enclosure system including a first primary enclosure volume, a second primary enclosure volume and a dividing wall positioned between the first and second primary enclosure volumes and having a first opening therein. At least one electro-acoustic transducer is mounted at the opening on the dividing wall and includes a movable diaphragm having a first surface area side and a second surface area side. The first surface area side communicates into the first primary enclosure volume and the second surface area side of the movable diaphragm communicates into the second primary enclosure volume. At least one differential area passive radiator is provided, including (i) a primary diaphragm surface area having a primary peripheral attachment surround, and (ii) secondary diaphragm surface area having at least a secondary peripheral attachment surround.

Abstract: A sound lens speaker system includes a concave sound lens, two upper frequency drivers, and a lower mid/low frequency driver. The mid/low frequency driver is oriented to fire sound waves towards the apex of the sound lens. The two high frequency drivers are positioned off axis between the mid/low frequency driver and the apex of the sound lens, and are preferably angled toward the apex of the sound lens. Sound waves from the high frequency drivers and mid/low driver are reflected by the sound lens into a downward substantially focused beam of full frequency spectrum sound. In a preferred embodiment, the sound lens has an upper parabolic portion and a coaxial lower parabolic portion defined by different parabolic equations and each having a respective focus. The high frequency drivers are preferably located along an arc through the upper focus and the mid/low frequency driver is substantially vertically aligned with the lower focus.