Abstract: An improved-fidelity speaker system is presented. The sound system includes a frame and a pair of matching speakers. The frame is formed to hold a first speaker and a second speaker, each having a front side, a back side, and central axis. When attached with the frame, the two speakers are substantially aligned along their central axes in a configuration selected from a group consisting of being mounted in the frame such that the front sides of the speakers are facing away from each other, and being mounted in the frame such that the front sides of the speakers are facing towards each other. When the speakers are operated in unison, a sound wave is generated and pushed outward from the frame and approximately radially from the central axes of the speakers in up to 360 degrees, expanding outward about a plane approximately perpendicular to the central axes.

Abstract: Acoustic devices that include passive radiators. The passive radiators may include an acoustic drivers. The acoustic device may be hand-held or pocket sized. The passive radiators may provide perceptible mechanical vibration.

Abstract: Adjustments to an electro-acoustic transducer may be made to match the performance of a second electro-acoustic transducer such that a net inertial force generated by movement of the electro-acoustic transducers' diaphragms are substantially zero. Adjustments may include adjusting a moving mass of one of the elector-acoustic transducers. Adjustments may include applying an equalization to one of the electro-acoustic transducers.

Abstract: There is provided a speaker connector including first and second speaker elements each having an inward face, an opposing outward face, and an engagement wall extending between the inward and outward faces. The speaker elements are connectable to the first and second speakers, respectively. A connector housing includes first and second end faces disposed on opposing sides of a housing medial portion. First and second inner walls extend inwardly from the first and second end faces, respectively, to define first and second housing recesses. The first and second inner walls are configured to engage with the engagement wall of the respective speaker elements with the first speaker element being received within the first housing recess and the second speaker element being received within the second housing recess.

Abstract: A handheld electronic device, such as mobile terminal, PDA or media player, includes a housing and a plurality of audio transducers supported by the housing and positioned at spaced-apart positions. The device further includes an audio circuit configured to change an allocation of audio transmission and/or reception functions among the plurality of audio transducers responsive to a user's mechanical interaction with the device, e.g., responsive to a change in an attitude at which a user is holding the housing and/or a change in a position of a moveable component of the device, such as a moveable display.

Abstract: A media playing device is provided. In an exemplary form, the media playing device includes a housing having a cylindrical end with an opening. The media playing device also includes a hollow turning knob. The knob has two protrusions on its inside surface. The media playing device additionally includes a PCB disposed inside the housing with a micro controller unit (MCU) and a pair of switches. The medial playing device further includes an attachment means for attaching the knob to the cylindrical end of the housing and allowing the knob to rotate with respect to the cylindrical end. When the knob is rotated in clockwise direction or counterclockwise direction, one of the two protrusions moves within the opening and can be moved to a position to contact one of the two switches to activate the switch. The activated switch sends a signal to the MCU and the MCU execute an operation.

Abstract: A micro magnetic device having a body defining at least part of an enclosed chamber, a pole comprising a soft magnetic material within the chamber, and an electrically conductive coil positioned around the pole. A diaphragm integral with the body defines a top of the chamber opposite the pole. The diaphragm supports a permanent magnetic film. Multiple micro magnetic devices can be combined to form an array. The micro magnetic device may be, for example, a speaker or a sensor. The micro magnetic device may be made by MEMS or thin film techniques.

Abstract: Sound signals to be output from a loudspeaker array are modified by a plurality of filters designed according to an unconstrained optimization procedure to improve overall performance (e.g., power, directivity) of the loudspeaker array. More particularly, respective filters are configured to receive a signal to be output to a plurality of loudspeakers. Upon receiving the signal, the respective filters individually modify the received signal according to the results of the unconstrained optimization procedure and then output the individually modified signals to respective loudspeakers. The unconstrained optimization procedure takes into account manufacturing tolerances and individually enhances the signal output to each of a plurality of individual loudspeakers within an array to achieve an overall improvement in performance.

Abstract: An acoustic device and method of making said acoustic device. The acoustic device comprises a diaphragm having resonant bending wave modes in the operating frequency range, and a plurality of electromechanical transducers coupled to the diaphragm. The positioning and mechanical impedance of the transducers are such that at least a selected number of the resonant bending wave modes are balanced so that the net transverse modal velocity over the area of the diaphragm tends to zero with the balancing of the resonant bending wave modes being achieved substantially by the positioning and mechanical impedance of the transducers. The parameters of the diaphragm may be such that there are a plurality of nodal grouped locations at or around which the nodal lines of a selected number of resonant modes are clustered. Each transducer may be mounted at one of the plurality of nodal grouped locations.

Abstract: In public audio presentation it is desirable that the playback loudness is continuously adapted to the background noise loudness. Such adaptation of the playback volume requires a continuous measurement of the loudness somewhere within the sound exposure area. A dipole loudspeaker panel has a strong attenuation of the emitted sound in the panel plane. When placing a microphone capsule in that plane but outside the panel, the sound emitted from the panel will be recorded by the microphone with a significant sound pressure level attenuation. Such specific microphone arrangement can capture the background noise without being unduly disturbed by the direct sound emitted from the loudspeakers.

Abstract: Loudspeaker apparatus comprise commonly some sort of casings or assemblies, in which one or more single speakers are integrated and which are used to convert electrical signals into sound. A loudspeaker apparatus 1 for radiating sound in a hemisphere is disclosed having a centre axis 9, the loudspeaker apparatus 1 comprising: a set of midrange drivers 6 a, b, c, d, e, f, whereby the midrange drivers 6 a, b, c, d, e, f are controlled and/or arranged in a Bessel configuration and are operable to provide a first acoustic field in the hemisphere, a set of tweeter drivers 7 a, b, c, d adapted to provide a second acoustic field in the hemisphere, whereby the first and the second acoustic field are respectively arranged symmetrically around the centre axis 9 of the hemisphere, whereby the main sound emitting directions of the single tweeter drivers 7 a, b, c, d are angled to the centre axis 9.

Abstract: The present invention provides a vertically or horizontally placeable combinative array speaker. The vertically or horizontally placeable combinative array speaker includes a microprocessor, an orientation sensor coupled to the microprocessor to sense condition changes of the combinative array speaker, a sound field reconstructing unit formed within or outside of the combinative array speaker, wherein the sound field reconstructing unit is coupled to the microprocessor to simulate surround sounds, and array speakers coupled to the sound field reconstructing unit through an amplifier.

Abstract: A loudspeaker system has a plurality of relatively small transducer elements configured in a closely spaced transducer array such that their acoustic outputs combine to produce a focused beam of sound in front of the array that is substantially uniform about the beams radiation axis. The transducer array lies in a plane and has a perimeter that approximates a circle, and will have fill-factor with respect to a circle circumscribing the array of at least approximately 70%. In one variation of the loudspeaker system, the transducer array is constructed in smaller transducer array modules that are operatively fitted together to produce a larger array.

Abstract: A speaker includes a housing; a support assembly installed on the lower end of the housing to support the housing; at least one first speaker unit installed in the housing to reproduce a sound signal; and a second speaker unit installed in the support assembly to reproduce a sound signal which belongs to a low sound band. Openings are defined through both sides of the support assembly to transmit to the outside sound reproduced by the second speaker unit. A guide cone is provided to the lower end of the support assembly to guide sound toward the openings. The speaker unit can be installed in a baffle which is supported at the opened front end of the housing to be rotated about a vertical axis. Through rotating the baffle, the speaker unit can be actually rotated within a predetermined range to change a sound transmission direction.

Abstract: A speaker system includes a first, second and third sound radiators with the second sound radiator positioned medially between the first and third sound radiators. The radiators project first, second and third sound vectors respectively, with the second sound vector oriented vertically and the first and third sound vectors directed generally toward each other at angles above the horizontal so as to intersect at an inclusive angle between 90 and 170 degrees. Sound from the first and third radiators impinges on the second radiator so as to cause an echo effect improving sound spaciousness. The first and third radiators are placed at different angles relative to the listener and at different heights as well to improve time delays in the two radiated signals.

Abstract: A MP3 loudspeaker system is disclosed. The MP3 loudspeaker system comprises a main loudspeaker and a sub loudspeaker connected by signal cables. The loudspeaker has a flat configuration and the edge of the loudspeaker is provided with magnetic element such that the main loudspeaker and the sub loudspeaker attract each other. The lower section of the main and sub loudspeaker is provided with a folding section and a signal cable connector. The loudspeaker can be folded and stand with the folding section as a support. The signal cable connector is also functioned as the base support for the loudspeaker.

Abstract: A mobile terminal includes a portable terminal housing and a speaker housing positioned in the portable terminal housing. The speaker housing includes a first micro-speaker having a first frequency response and a second micro-speaker having a second frequency response and positioned proximate the first micro-speaker. The terminal housing further includes a first passageway extending from a front face of the first micro-speaker to a first opening in the terminal housing, and a second passageway extending from a back face of the second micro-speaker to a second opening in the terminal housing displaced from the first opening. A grommet adjacent the speaker housing acoustically separates at least a portion of the first passageway from the second passageway. The first passageway may be completely acoustically separated from the second passageway by the grommet and/or a gasket and/or a foam structure.

Abstract: An electro-acoustic drive unit includes at least one permanent magnet assembly and at least an inner pole piece and an outer pole piece forming a pair of pole pieces, the permanent magnet assembly together with the pair of pole pieces forming a magnetic circuit with a pole gap for exciting a voice coil assembly. The pole gap is arranged to provide a magnetic field directed radially with respect to a center axis of the loudspeaker, and the permanent magnet assembly includes at least two permanent magnetic bars, with radially extending magnetization direction with respect to the center axis of the loudspeaker.

Abstract: Provided is a method and apparatus for focusing sound using an array speaker system. The method includes generating a plurality of delayed signals to be focused to a predetermined position from an input signal, filtering a low-frequency signal having a frequency that is lower than a reference frequency from the delayed signals, generating low-frequency focusing signals divided into 2 groups by adjusting a gain of the filtered low-frequency signal, and applying the low-frequency focusing signals divided into the 2 groups to speaker units of the array speaker system at both sides with respect to a center portion of the array speaker system and outputting the low-frequency focusing signals through the speaker units. In this way, the performance of sound focusing for the low-frequency signal can be improved and thus a listener located a predetermined distance from and in a predetermined direction relative to the array speaker system can clearly listen to the low-frequency focusing signals.

Abstract: Loudspeakers optimized for use in array environments are described herein. In one embodiment, a system includes a transducer-array module having a plurality of piston-based transducers. Each transducer is configured to drive a particular one of a plurality of discrete non-concentric acoustic-radiating diaphragms. A frame is positioned around an outermost boundary of a plurality of the discrete non-concentric acoustic-radiating diaphragms, which are adjacent to the outermost boundary. The transducer-array module may be used in array configurations, including, but not necessarily limited to: line, planar, and phased arrays.

Abstract: A speaker apparatus is configured such that a speaker unit including a single magnetic circuit system, a plurality of vibration systems and a case is housed inside a speaker box. In the speaker unit, magnetic gaps having a magnetic field of the same magnitude are defined by a magnet holder, a magnet and a yoke in each of the vibration systems. In one vibration system and the other vibration system, voice coils are wound around voice coil bobbins in directions reverse to each other. Consequently, the vibration systems are moved in directions opposite to each other by the same force by applying the same electric signal to the voice coil in each of the vibration systems from an amplifier. Therefore, acoustic waves are radiated in the directions opposite to each other.

Abstract: The present invention discloses an electronic apparatus of splittable type comprising at least two speaker portions, the two speaker portions are connected by electro-wires, wherein in one speaker portion is provided a winding mechanism for pulling-out and retracting-in the electro-wires; each of the speaker portions has a voice chamber, and the voice chambers in the two speaker portions have the different shapes from but substantially the same volumes as each other.

Abstract: A loudspeaker drive unit includes at least one voice coil, a diaphragm, permanent magnet element and pole piece element. The permanent magnet element and pole piece element form a magnetic circuit with a pole gap arranged to receive and interact with the voice coil. The magnetic circuit is arranged to provide a magnetic field directed radially in the pole gap. The voice coil, the diaphragm and a support structure forms a voice coil and diaphragm assembly, which is arranged to be a self-supported unit. The voice coil and diaphragm assembly is removable from the magnetic circuit as a separate unit, allowing convenient replacement of the dynamic parts of the loudspeaker drive unit.

Abstract: A loudspeaker driver that includes a suspended diaphragm and a plurality of voice coils each suspended in a magnetic field and coupled to the diaphragm.

Abstract: Provided are an array speaker system and a method of implementing the same. The array speaker system includes a group setting unit setting one or more combinations of a plurality of speakers included in an array speaker system into at least one group according to a predetermined adjustment factor, a signal assignment unit dividing an input signal into at least one sound source signal according to the adjustment factor and selectively assigning the divided sound source signal(s) to the set group(s), a sound adjustment unit adjusting a sound source signal to be output through speakers within the group according to sound source characteristics of the group, and a signal output unit outputting the adjusted sound source signal through the speakers within the group.

Abstract: A flexible speaker including a retractor, a flexible speaker panel, and at least one support element is provided. The flexible speaker panel is connected to the retractor, and is capable of being rolled up and received in the retractor. The support element, capable of memorizing shape, is disposed on the flexible speaker. The support element is used for being rolled up and received in the retractor, together with the flexible speaker. When the flexible speaker panel is spread from the retractor, the support element supports the flexible speaker and keeps the flexible speaker panel being steady in a spread state, and the size of the spread region is determined by the user.

Abstract: Personal communication method and apparatus, such as telephone handsets and headsets, with acoustic stray field cancellation are disclosed. The personal communications device employs an echo canceling receiver generally including two displacement sources that are not in phase formed by at least one driver, an acoustic cavity corresponding to each displacement source, and an acoustic output port corresponding to and in acoustic connection with each displacement source via the corresponding acoustic cavity such that the acoustic length between the acoustic centers of the two ports is less than the distance between the acoustic center of each port and the acoustic center of the corresponding displacement source to which the port is acoustically connected. In another embodiment, the ports may be such that both ports are located on a same side of a surface of at least one of the displacement sources.

Abstract: The invention relates to a filter element comprising a support with an outside surface and at least three channels in the support. The channels comprise a peripheral wall directed towards the outside surface, the distance between the peripheral wall and the outside surface reducing on each side of the middle of the peripheral wall. The element has the advantage of improved strength when subject to severe conditions of use.

Abstract: A coaxial loudspeaker for reproducing an electrical sound signal is provided. The loudspeaker has a magnetic driver assembly with a first annular slot and an opposed, coaxial second annular slot, each establishing a permanent magnetic field therein from a single magnet. Independently driven first and second voice coils are positioned within the respective one of the first and second annular slots, each being connected to a transducer element.

Abstract: An audio transducer component comprises at least two independent voice coils, each voice coil associated with a diaphragm and an acoustic cavity. The audio transducer component further comprises magnetic means for driving the at least two independent voice coils with independent signals.

Abstract: A speaker system having a structure in which the room surrounding the first diaphragm and the room adjacent to the second diaphragm are acoustically coupled. The second diaphragm has coating on a surface. Applying the coating to the second diaphragm enhances the reliability and performance of the speaker system. Besides, the diversely definable geometry of the diaphragm allows an electronic device employing the speaker system or the speaker module to have flexibility in design.

Abstract: An earpiece speaker system including an earpiece body through which an audio signal is provided, the earpiece body having a speaker mount surface, and a plurality of speaker modules mountable to the body. Each of the speaker modules includes a mount surface for mating with the earpiece body speaker mount surface for securing the speaker module thereto in order to reproduce the audio signal.

Abstract: A sound device for carrying out a homogenous sound cover for a public addressed area includes an electroacoustic source network (1), wherein each electroacoustic source (1) diffuses a version delayed by a delay (3), filtered by a filter (4) and amplified by the device input signal amplifier (5). The network is substantially rectilinear and vertical, angles ? which are formed by the emitting axes of the electroacoustic sources (1) and a normal to the network are selected such that ?n>?n?1, wherein n is the index of the electroacoustic sources (1) numbered in ascending order from the top of the device to the bottom thereof and the delays (3) interact with the angles ? in such a way that the device generates a wavefront (6) whose shape corresponds to the desired sound cover of the public addressed area.

Abstract: A sound reproduction system includes one or more arrays of drive units, coupled with sound processing allowing improved steerability, directional control, width control, and/or beam overlay. A speaker column may comprise two arrays facing one another, the drive units being perpendicular to the speaker unit front, with the acoustic output of each line array being compressed, turned and output from an elongate slot. The drive units may be staggered with respect to those in the opposing array. The arrays may be arc-shaped else straight. Selective delays to simulate an arced pattern. Differential delays applied to the drive units in a sub-array allow beam steering. Additional drive units, such as high frequency drivers, may be added along the length of the elongate slot or elsewhere to increase the dynamic frequency range of the speaker system. A collocated sound processor and amplifier output stage may be integrated with the speaker unit.

Abstract: A loudspeaker comprising a magnet unit that generates a magnetic field and a membrane which is mounted in a frame and which is provided with an electrical conductor arranged in a pattern on the membrane, which membrane is positioned in the magnetic field in such a manner that a force is exerted when current is fed through the conductor pattern on the membrane, which force is capable of setting the membrane vibrating to produce sound, said loudspeaker being provided with a sound opening located between the vibrating region and the outer side of the loudspeaker, which sound opening connects to a sound horn having diverging walls, characterized in that substantially identical sound openings and sound horns connecting thereto extend on both sides of the membrane.

Abstract: A speaker system having a first speaker, a second speaker, and a housing having a first mounting surface to which the first speaker is mounted and a second mounting surface to which the second speaker is mounted. The first mounting surface and the second mounting surface are substantially planar and abut one another to form an included angle of between 120 degrees and 140 degrees. By so arranging the mounting surfaces, the sound produced by each speaker is allowed to mix to provide a full sound.

Abstract: A low-frequency loudspeaker system based on a dipole principle. In some implementations, the system includes an open frame rigging system and multiple subwoofers mounted in a dipole surface array configuration in the open frame rigging system to produce controlled sound dispersion in both horizontal and vertical planes. The subwoofers are operable to produce low-frequency sound dispersion below about 300 Hz. The subwoofers mounted in the dipole configuration include a first set of subwoofers facing a first direction and a second set of subwoofers facing a second direction, in which the second direction is facing a direction that is 180 degrees with respect to the first direction. The second set of subwoofers are wired out-of-phase with respect to the first set of subwoofers to reduce non-liner distortion. The first and second sets of subwoofers are configured to concurrently move in a same direction when a signal is applied to the subwoofers.

Abstract: In some cases, constant directivity of a speaker system is desirably obtained in a wider frequency range. However, a speaker system using a constant directivity horn is frequently used in combination with a box speaker containing a woofer unit. Such a system becomes large in size. Furthermore, constant directivity is desirably obtained in a lower frequency. A speaker system 10 includes an enclosure 20, a first speaker unit 30 for low frequency and a plurality of second speaker units 31, 32, and 33 for high frequency. The enclosure 20 includes a front plate portion 21 which is a baffle plate and a rear plate portion 23. A length of the rear plate portion 22 in a first direction perpendicular to a forward and backward direction is shorter than a length of the front plate portion 21 in the first direction. The first speaker unit 30 and the second speaker units 31, 32, and 33 are mounted to the front plate portion 21. The plurality of second speaker units 31, 32, and 33 are arranged in the first direction.

Abstract: Surround sound recording is a tedious task requiring the use of many microphones. The invention aims at enabling the use of two-channel microphones (or stereo microphones) for multi-channel surround recording. A conventional stereo microphone, or a two-channel microphone specifically optimized for use with the proposed algorithm, is used to generate two signals. A post-processor is applied to the microphone generated signals to convert them to multi-channel surround. This aim is achieved through a method to generate multiple output audio channels (y1, . . . , yM) from two microphone generated audio channels (x1, x2), in which the number of output channels is equal or higher than two, this method comprising the steps of: determine directions of sound components related to the microphone characteristics determine compensation gains of sound components related to the microphone characteristics generating the output audio channels, y1, . . .

Abstract: An output control system includes a plurality of output control apparatuses, the output control apparatuses controlling audio signals supplied to respective two-dimensionally arranged loudspeakers, including at least two loudspeakers in a vertical direction, and at least two loudspeakers in a horizontal direction, the audio signals respectively corresponding to images displayed on an array of a plurality of displays forming a multi-display apparatus. Each of the output control apparatuses includes a communication unit for exchanging information relating to one of a state and a process result of own apparatus with another output control apparatus, and a signal processing unit for processing an audio signal to be output to the corresponding loudspeaker based on the information relating to the other output control apparatus received via the communication unit.

Abstract: A sound transducer (10) for imparting acoustical energy directly to a solid surface (12) while achieving the sound quality and frequency response found only in conventional diaphragm speakers. The sound transducer (10) comprises a pair of symmetrical magnet assemblies (16, 18), a pair of symmetrical voice coils (66, 68), and an actuator (22). The magnet assemblies (16, 18) each present an area of concentrated magnetic flux (60, 62). The symmetrical voice coils (66, 68) are positioned in the vicinity of the areas of concentrated magnetic flux and are operable to receive an alternating audio signal which causes the voice coils to move relative to the magnet assemblies. The actuator (22) moves with the voice coils and includes a foot (70) for coupling with a solid surface to impart movement to the solid surface and thereby produce sound when the voice coils receive the audio signal. The actuator (22) is coupled to the voice coils (66, 68) by an elongated shaft (24).

Abstract: An electro-acoustic drive unit including at least a first and a second drive unit, each provided with a pole gap for exciting respective voice coil assemblies, at least one permanent magnet means is arranged to be a part of the magnetic circuit of both the first and the second drive unit. The pole gaps are arranged to provide magnetic fields directed radially with respect to a center axis of the loudspeaker, and the permanent magnet means has radially extending magnetization direction with respect to the center axis of the loudspeaker.

Abstract: The present invention is directed to a table that is constructed to receive an audio system and an audio system that is intended to be incorporated within a tabletop. The audio system comprises a housing and an audio column having a speaker wherein the audio column is capable of being retracted into the housing such that the top wall of the audio column is substantially co-planar with a tabletop. Additionally, the present invention includes a method of conducting business meetings including releasing a mechanism causing the audio column to extend out of the housing; allowing sound to travel through the speaker during the meeting and to be heard by participants in a room where the tabletop is located; and closing the audio column such that the audio column is received within the housing and the top of the audio column is at least substantially co-planar with the tabletop.

Abstract: Allpass arrays of arbitrary order are presented. The transducers in the arrays are configured with weights corresponding to the FIR approximation of an allpass filter such that a nearly uniform array response is provided.

Abstract: An earphone including a case, a case extension unit, a plate, a cover, a first speaker and a second speaker is provided. The first speaker is disposed on a supporting portion of the plate and is disposed on a first plane different from a second plane where the second speaker is located. A distance exits in the position of the first speaker and the position of the second speaker corresponding to a direction of the sound from the earphone to the user who wears the earphone. The distance variation can make the sound field have more special effects and have better frequency response in some frequency domain. The distance variation can also avoid the interference of different sound fields generated by the speakers inside the earphone, and thus improves the performance of the whole sound field.

Abstract: A speaker system functioning as a stand capable of power supply to a mobile phone and hand-free communication and being capable of derived surround reproduction or stereo reproduction is provided. An enclosure (201), on which a mobile phone is placed, includes therein supply means (209) for supplying electric power to the mobile phone, communication means (213) for enabling hand-free communication by the mobile phone through a microphone (211), processing means for introducing signals from the mobile phone and performing a predetermined processing, and a pair of speakers (215, 215?) provided on both sides of the enclosure in a state in which back sides thereof are substantially face to each other for generating sounds based on output signals from the processing means.

Abstract: A voice coil and a magnetic driving circuit oscillate a diaphragm and a center cap. A magnetic lighting circuit for providing a magnetic field to an induction coil is mounted separately from a magnetic driving circuit. The induction coil generates an electromotive force for lighting light-emitting devices. Further, the light-emitting devices, the induction coil, and the magnetic lighting circuit are mounted integrally on the center cap.

Abstract: A line array electroacoustical transducing system includes at least first and second line arrays detachably secured in electrical and mechanical coupling relationships. The assembly may be detachably secured to a base having an amplifier in electrical and mechanical coupling relationships.

Abstract: A loudspeaker and method of assembly according to this invention provides for precise alignment between the frame and motor structure before they are connected to one another, and employs a fixture to form the moving assembly of the speaker, i.e. the voice coil, upper and lower suspensions and diaphragm, outside of the frame so that concentric tolerance stack-up is minimized. The moving assembly, once formed, is mounted as a unit to the frame and motor structure to facilitate assembly and repair of the speaker.

Abstract: A multi-channel headphone includes a case adapted to be worn on user's ear and cover the whole ear, in which a middle speaker, a front speaker, rear speaker and a bass speaker are provided. The front speaker has a broadcasting portion facing a front side of an auricle of the ear and the rear speaker has a broadcasting portion facing a rear side of the auricle. The headphone provides a sound closing to the idea surround sound.