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 parametric loudspeaker which uses multiple piezoelectric bimorph transducers. These multiple piezoelectric bimorphs have a resonant frequency which varies from unit to unit. The phase response at and near the resonant frequency changes at a very high rate with slight changes in frequency. The associated modulator electronics have a primary carrier frequency that is optimized for maximum parametric output. This is achieved by aligning the carrier frequency with the flattest portions of the phase curve for maximum phase coordination among the multiple devices.

Abstract: The present invention is an improved loudspeaker with greatly reduced impedance and improved response and power handling in the low frequency range. The benefits of the present invention derive from a novel, synchronized, multiple driver design in which the output of a first driver is synchronized with the output of a second driver to produce an acoustically reinforced output. This synchronization is achieved through a phase shift of the input signals to the drivers.

Abstract: A ceiling panel speaker 100 comprises ceiling panel vibrating plates 110 and exciter units 200 mounted on said vibrating plates 110, each exciter unit 200 connected via line 270 to an amplifier not shown. The ceiling panel vibrating plates 110 are aligned to form a longitudinal size L1 extending above one or more aisles within the cabin, so that the ceiling panel speaker 100 realizes a long surface sound source. The sound waves output from the ceiling panel speaker 100 are transmitted along inner wall panels 12 etc. and spread throughout the closed space of the passenger cabin 50.

Abstract: A modular audio loudspeaker array system. The system includes a first speaker module, and a second speaker module, constructed and arranged to radiate sound waves responsive to audio signals. Sound waves radiated by the first speaker module and the sound waves radiated by the second speaker module combine to form a radiation pattern. The system further includes a positioning system, for positioning the first bass module relative to the second bass module at a plurality of fixed predetermined distances; an audio signal input terminal electronically for coupling the loudspeaker array to a source of the audio signals for receiving the audio signals; an audio signal processing device, electronically coupling the audio signal input terminal to the first bass module and to the second bass module, for processing the audio signals and transmitting the audio signals to the first speaker module and to the second loudspeaker module.

Abstract: A sound system assembly for use in a hand held device is provided. The sound system assembly includes a pair of transducers, and a corresponding pair of manifolds, which redirect the sound produced by the transducers away from the front or back surface of the device toward respective side facings of the hand held device. By redirecting the sound produced by the transducers, the apparent source of each audio source, corresponding to the respective opening in each of the sides of the hand held device through which the sound waves exit the device, is displaced further apart horizontally.

Abstract: A speaker system includes a first speaker; a second speaker; and a first spacer for separating the first speaker and the second speaker from each other so that the first speaker and the second speaker face each other. The first speaker and the second speaker are located so that opposing faces of the first speaker and the second speaker output sounds of an identical phase. The first speaker, the second speaker and the first spacer form a first sound path through which the sounds output from the opposing faces of the first speaker and the second speaker pass. The speaker system according to the present invention includes n number speakers and (n−1) number of spacers and can be arranged so that the opposing faces of even-numbered speakers and odd-numbered speakers output sounds of an identical phase.

Abstract: The stereo speaker includes at least one speaker and a sonic reflector. The speaker has a sound output opening where the sonic reflector is set. The sonic reflector reflects the sonic waves created by the speaker in the direction substantially perpendicular to the direction in which the sonic waves are generated from the speaker. The reflected sonic waves are circularly scattered from the stereo speaker.

Abstract: Defects in principle of low-frequency sound reproduction that conventional technologies essentially have are overcome by using a novel method for performing direct modulation when an air-current occurs. There is provided a speaker system, including an air-current generating unit for generating an air-current, and an air-current modulating unit for frequency-modulating the air-current generated by the air-current generating unit with a sound signal to which the driving of the air-current generating unit is input to generate sound waves in accordance with the sound signal.

Abstract: An automobile audio system having reflected sound distribution in which a linearly spatial sound image can be created giving the listener sound from the left, right, and center using preferably mid-to-high frequency range speakers. This linearly spatial sound image is created by placing a pair of mid-to-high frequency range speakers in a generally center section of the upper dashboard surface in an automobile and directing the sound emitted by the speakers towards the forward respective interior corners of the automobile wherein the left speaker is directed towards the left corner and the right speaker is directed towards the right corner. In this manner, the sound from the mid-to-high frequency range speaker is axially directed away from the occupants and reflected back to the occupants using the interior surfaces of the automobile.

Abstract: A speaker device has a pair of speaker units each including a magnetic circuit. The magnetic circuits are opposed and connected to each other by a binding member. Vibrations generated by the speaker units are canceled to each other so that the occurrence of unnecessary vibrations can be suppressed and the transient characteristic can be improved. Acoustic load members are arranged in the front portions of frames so that the resonance frequency can be lowered and a band of reproducing sound of low frequency can be expanded.

Abstract: This invention describes a loudspeaker implementation which can adaptively reduce the transmission of an acoustic signal to listeners other than the intended listener. The invention uses a dipole loudspeaker implementation with two acoustic sources, each of which is driven by a separate signal. By introducing a predetermined phase difference between the signals produced by the two acoustic sources, the null in the standard dipole spatial directivity pattern may be moved to any desired direction. Alternatively, using a microphone close to the unintended listener's ears and a suitable feedback arrangement, the null can adaptively be aligned with the direction of minimum desired sound transmission. This invention, therefore, provides a solution for applications where it is preferable to reduce the transmission of sound in particular directions while providing the listener with headphoneless audio.

Abstract: In an adapted to be used in an on-ear mode and in an off-ear mode a holder compartment (6)accommodates a first transducer (20)and a second transducer (25)and the holder compartment (6)is bounded by a bounding wall (7)formed with internal sound ports (10, 11)and at least one additional internal sound port (22), and an outer wall (3)formed with external sound ports (15, 16)is spaced at a distance from the bounding wall (7), and at least one additional external sound port (19)is provided between the bounding wall (7)and the outer wall (3), and the two transducers (20, 25)can be driven with useful signals of the same phase in the off-ear mode and with useful signals of opposite phase in the on-ear mode.

Abstract: A sound-driving loudspeaker system achievable with a simple structure and capable of easily improving acoustic characteristics is provided. The loudspeaker system according to the present invention emits sound by driving a diaphragm panel 14 by an electromechanical acoustic transducer 12. The loudspeaker system includes a board 10, the diaphragm panel 14 whose rim is fixedly attached to the board 19 so as to form a space 16 and which has a stiffness lower than that of the board 10, and the electromechanical acoustic transducer 12 for emitting sound into the space 16. With this structure, the diaphragm panel 14 is flexed to be vibrated by the sound emitted from the electromechanical acoustic transducer 12.

Abstract: A portable spa including an audio system designed to use the spa shell as the sound generating device. Transducer devices are mounted within an enclosure which is bonded to the spa shell so as couple the sound vibration energy to the shell so that sound can be heard when using the spa.

Abstract: A portable spa including an audio system designed to use the spa shell as the sound generating device. Transducer devices are mounted within an enclosure which is bonded to the spa shell so as couple the sound vibration energy to the shell so that sound can be heard when using the spa.

Abstract: Two or more speakers are used to generate complimentary sound waves within a soundproof cabinet. The sounds generated inside the cabinet are detected by a microphone and sent to an external device for recording or listening purposes. In one embodiment, two speakers are arranged side-by-side and mounted on a panel. The panel serves to section off two chambers within the cabinet. The primary chamber is the chamber toward which the speakers are facing. The secondary chamber is the chamber within which the backs of the speakers are positioned. The speakers are connected to the input signal in reverse polarity of each other. Thus, during operation one speaker is pushing air outward while the other is pulling air inward. This complimentary generation of sound waves alleviates the muffling effect of the small isolated space and allows the speakers to generate sound as though they were in a much larger open area. Thus, the sound picked up by the microphone is very close to the desired “live” sound.

Abstract: A speaker system includes two cylindrical tubular cabinets. Each cabinet has a vertical longitudinal axis and defines a cylindrical cabinet cavity therein. At least one speaker element is located in each cavity. Preferably, there are upper and lower speaker elements mounted within each cavity, and dividing the cavity into upper, middle and lower speaker cavity portions. The speaker system is particularly constructed for reproduction of the very low frequency audio data below 200 Hz, and preferably below 60 Hz, which is associated with modern high fidelity sound sources such as those using a Dolby®5.1 format.

Abstract: Two or more speakers are used to generate complimentary sound waves within a soundproof cabinet. The sounds generated inside the cabinet are detected by a microphone and sent to an external device for recording or listening purposes. In one embodiment, two speakers are arranged side-by-side and mounted on a panel. The panel serves to section off two chambers within the cabinet. The primary chamber is the chamber toward which the speakers are facing. The secondary chamber is the chamber within which the backs of the speakers are positioned. The speakers are connected to the input signal in reverse polarity of each other. Thus, during operation one speaker is pushing air outward while the other is pulling air inward. This complimentary generation of sound waves alleviates the muffling effect of the small isolated space and allows the speakers to generate sound as though they were in a much larger open area. Thus, the sound picked up by the microphone is very close to the desired “live” sound.

Abstract: A loudspeaker system includes an enclosure supporting first and second loudspeaker driver assemblies and having an internal volume. At least the first loudspeaker driver assembly is constructed and arranged to radiate sound energy into the listening region outside the enclosure over at least the range of audio frequencies above a predetermined first frequency. The second loudspeaker driver assembly is constructed and arranged to radiate sound energy over a first predetermined range of audio frequencies embracing at least a range of audio frequencies below a second frequency above the first frequency. The first loudspeaker driver assembly, the second loudspeaker driver assembly and the enclosure are constructed and arranged to coact to maintain the pressure in the enclosure substantially constant over at least the range of frequencies between the first and second frequencies.

Abstract: An optoelectronic module and a method for stabilizing its temperature are disclosed wherein the measurement of the reference temperature for the temperature sensor takes place on the substrate surface for the optoelectronic component, so that high temperature stability is ensured.

Abstract: A bending wave panel-form loudspeaker comprises a spaced pair of panels supported at their edges and defining between them a shallow sealed fluid cavity. Vibration exciters are disposed in the fluid cavity and are arranged to drive the respective panels. The electrical connections to the exciters are at least partially in antiphase such that the predominant motion of the panels is in phase to provide a degree of dipole radiation property for the loudspeaker. The gap between the panels is in the range 2 to 25 mm such that the shallow cavity provides conditions in which fluid coupling dynamics and behavior is asserted between the pair of panels due to the fluid layer between them.

Abstract: A system and method which generates amplified signals indicative of left and right stereo channels, and uses the signals to drive transducers for each of subwoofer, left stereo, and right stereo channels. The amplification circuitry is operable with a power supply having low peak current capability (i.e., low peak to average current rating) even when amplifying an input signal pair having highly correlated frequency components, since it spreads the peak current demands imposed on the power supply over a full cycle of each of the highly correlated frequency components. A series-connected pair of left and right channel transducers is driven by left and right channel power amplifiers of the amplification circuitry, and the subwoofer channel transducer is connected in parallel with this transducer pair so that all three transducers are driven by two power amplifiers, thus eliminating the need for a third power amplifier to drive the subwoofer channel transducer.

Abstract: A method and device are provided for influencing an impression which is subjectively perceived by an occupant of a vehicle, in particular of a passenger car, when the vehicle is being operated. The primary oscillations which are produced when the vehicle is being operated are determined. Data for secondary oscillations are acquired from the primary oscillations and are converted at least in part into vibration oscillations which can be perceived through the human body. At least one of the components of the vehicle body is excited using the vibration oscillations, the vibration oscillations being placed in an interference relationship with the primary oscillations. In particular, the steering wheel is also excited so as to undergo mechanical vibration oscillations.

Abstract: The loudspeaker system uses an inner transducer for pressure control in the closed loudspeaker housing to simulate the desired baffle properties. The speed of the membrane of the inner transducer is either proportional to the derivative of the pressure, or proportional to the intergral of pressure changes, or comprises summands proportional to the pressure, to the pressure's derivative and to the pressure's intergral.

Abstract: A sound apparatus capable of obtaining a clear sound (audio image) irrespective of a position of a speaker portion to be provided in the sound apparatus. The sound apparatus includes a speaker portion and a plurality of sound guides each of which has one end portion connected to the speaker portion and has the other end portion opened; wherein lengths of the plurality of sound guides are nearly equal to each other and the other end portions of the sound guides are arranged such that sounds generated from the speaker portion are guided through the sound guides and collide with each other.

Abstract: A loudspeaker unit comprises a loudspeaker box, a first loudspeaker attached to a front panel of the loudspeaker box, and a second loudspeaker having the same diameter as that of the first loudspeaker and attached to an upper panel of the loudspeaker box. The first loudspeaker is driven in a positive polarity and the second loudspeaker is driven in a negative polarity. Driving voltages E1 and -E2 respectively for driving the first and the second loudspeaker are optional voltages meeting E2/E1<1. The sound pressure of sounds radiated by the second loudspeaker is lower than that of sounds radiated by the first loudspeaker. The directivity factor of the synthesis sound pressure of the first and the second loudspeaker at a sound receiving position with respect to the 90.degree.-direction is equal to the product of the directivity factor D(90.degree.) of the loudspeaker and a value (1-.alpha.) smaller than one. Accordingly, the output sound pressure of the loudspeaker can be reduced regardless of frequency.

Abstract: This invention minimizes the space required for a speaker system for a multimedia personal computer display on a desktop. The speaker system has a very thin shape, moderate cost, very good impulse and phase response for a crisp sonic detail and good directionality for use by a single listener seated in front of the multimedia personal computer display without disturbing others nearby. Each component of the speaker system is attached to or incorporated in the right or left side of the computer display. Each component comprises a plurality of small speakers arranged in a vertical, linear array. Preferably, each plurality includes a small folded waveguide which is acoustically coupled to the rear of each of the speakers. The folded waveguide is in a unique sheet configuration and enables directional ports in a treble component and a folded variable impedance maze in a base waveguide. The speaker system provides the required shape, clarity and listener isolation needed in the personal multimedia market.

Abstract: A plurality of speakers are arranged in line, and a plurality of digital filters are provided for the speakers. Each of the digital filters is applied with a plurality of audio signals. Characteristics of each digital filter is adjusted so as to provide patterns of directivity to each speaker dependent on the input audio signals.

Abstract: This loudspeaker system overcomes the disadvantages of prior art bipolar loudspeaker systems in which the front and rear-mounted driver(s) are connected with the same electrical phase. It compensates for the undesirable cancellation and reinforcement effects of prior art in bipolar loudspeaker design caused by the interaction of the front and rear acoustical output of the two drivers over certain frequency ranges. The introduction of a third side-mounted driver(s) to an enclosure whose depth exceeds its width when viewed from the front compensates for the usual cancellations and reinforcements of acoustic level that would normally occur in previous bipolar loudspeaker designs. This loudspeaker uses electronic, electrical and acoustical frequency-dividing networks to allow compensation of the acoustic level and the interaction of the front, rear and side-mounted driver(s) in such a way as to provide a nearly constant acoustic level over the entire operating range of the loudspeaker.

Abstract: The device simulates actively an acoustical impedance. The simulation is achieved by sensing the air pressure on the surface of the membrane of an electrodynamic transducer and by moving the membrane with a speed and an acceleration which depend upon the pressure according to the desired impedance function. It can be used in loudspeaker systems with closed housings to eliminate standing waves inside housings.

Abstract: A hollow structural component which includes an integral structure, partition walls intersecting each other within the integral structure, and a plurality of independent hollow portions formed as specified by the partition walls so as to be arranged within the integral structure. The integral structure is formed into one piece by one-shot molding or by one injection molding die which is caused to slide against each other between its stationary side and movable side for post-forming, whereby weight reduction of the hollow structural component, reduction in the amount of resin used, reduction in the number of parts involved, and improvement in the workability for assembling may be achieved with consequent cost reduction.

Abstract: A speaker system for use in a thin film video monitor apparatus is disclosed. The video monitor apparatus includes a thin film video display panel as well as a stiffening panel adjacent to the thin film video display panel. Next, a plurality of piezo speaker transducers are attached to one of the sides of the stiffening panel. The stiffening panel typically is composed of a material such as aluminum honeycomb sheets or a polycarbonate sheet. Other materials for use as the stiffener may include magnesium shells or ABS plastic. The speakers are defined so that a first sound channel and a second sound channel are provided, and these sound channels can define a left and right channel for proper stereo imaging. Between the video monitor and the stiffening panel is located an electromagnetic interference (EMI) shield.

Abstract: To obtain a directivity pattern representing the directivity of an original or virtual sound source, directivity patterns of different sources are composed algebraically. To take account of the progress of the directivity patterns of sources that differ with the frequency, the signals applied to these sources are filtered so that the composite directivity function represents the expected directivity pattern throughout the spectrum. The coefficients of the filters are determined by a method of optimization in modulus and in phase.

Abstract: A subwoofer including a walled cabinet defining an enclosed space of less than 1 cubic foot; axial openings formed in two opposed cabinet walls; and, two driver assemblies mounted within the cabinet on a common axis with the wall openings.

Abstract: This invention minimizes the space required for a speaker system for a multimedia personal computer display on a desktop. The speaker system has a very thin shape, moderate cost, very good impulse and phase response for a crisp sonic detail and good directionality for use by a single listener seated in front of the multimedia personal computer display without disturbing others nearby. Each component of the speaker system is attached to or incorporated in the right or left side of the computer display. Each component comprises a plurality of small speakers arranged in a vertical, linear array. Preferably, each plurality includes a small folded waveguide which is acoustically coupled to the rear of each of the speakers. The folded waveguide is in a unique sheet configuration and enables directional ports in a treble component and a folded variable impedance maze in a base waveguide. The speaker system provides the required shape, clarity and listener isolation needed in the personal multimedia market.

Abstract: A speaker system includes a vertically oriented elongated tube supported on a ground surface, and open at upper and lower ends thereof; a woofer, mid-range speaker and tweeter mounted at a lower end of the tube, the woofer having a front driving face with an effective driving area, the woofer providing an in-phase audio signal directed upwardly through the tube and an out-of-phase ground wave audio signal directed in an opposite direction therefrom; an enclosure enclosing the woofer and mounting the tube on the ground surface; a restricted open area formed between a lower edge of the enclosure and the ground surface and being less than the effective driving area, the restricted open area being arranged to transmit the out-of-phase ground wave audio signal from the woofer in a direction transverse to the axial direction; and a driving circuit for driving the woofer and including a power amplifier for amplifying an input signal with a variable gain and supplying the amplified input signal to the woofer, a circu

Abstract: An audio output system, having loudspeakers with an asymmetrical output in response to symmetrical modulated input signals, is provided with a unidirectional limiting circuit for proportionally reducing input signals of a polarity to drive the loudspeaker in the direction of its greatest response. In its basic form, the limiting circuit is a voltage limiting circuit, preferably a voltage divider, which includes a rectifier device. When the driving signal is of a polarity to produce a greater response from the loudspeaker, the rectifier device conducts and the magnitude of the signal voltage is reduced, resulting in substantially greater uniformity of output response of the loudspeaker in both directions. When the limiting circuit is placed on the input side of the power amplifier, the rectifier device advantageously is a vacuum tube connected as a diode. When located in the output stages of the power amplifier, where higher signal voltages are available, solid state rectifier devices may be employed.

Abstract: A loudspeaker system includes a flexible compressible tube having a woofer mounted at one end with its cone directed outward, and a vented baffle mounted at the other end. A first sound dispersion element is mounted with its apex facing the cone of the woofer and a midrange speaker is mounted in the base of the dispersion element with its cone facing away from the tube. A second sound dispersion element is mounted with its apex facing the cone of the midrange speaker, and at least one tweeter is mounted on the base of the second sound dispersion element with its cone facing away from the tube. According to one embodiment, a plurality of tweeters are mounted in an enclosure mounted on the base of the second dispersion element. According to another embodiment, a single tweeter is mounted in the base of the second dispersion element and a third dispersion element is mounted with its apex facing the cone of the tweeter.

Abstract: A compact full-range loudspeaker system includes an elongated enclosure having two open ends joined by a hollow interior, which enclosure may be of fixed dimension or telescoping, and has a full-range speaker mounted at each end of the cylindrical enclosure. The enclosure length is set in a range governed by the small speaker size to maximize the system response, particularly in the lower frequency range, and a dampening material is provided to construct the enclosure to minimize the structural acoustic response of the enclosure when being driven. A pair of miniature sound boards may be flat, polymer surfaces mounted to a base and positioned at each end of the cylindrical enclosure at an angle facing each speaker for reflecting sound waves emanating from the speaker in accordance with the positioning of the cylindrical enclosure to create an effective sound stage and control directionality.

Abstract: The efficiency of a vertical array speaker device is raised to obtain an adequate level of sound and to confine the horizontal radiation of the listening area of a surround sound system. A pair of baffle boards are mounted to a vertical array (4) with small diameter speakers (3), in symmetrical opposition, the boards are attached together at their rear edges (1a, 1b,) while the front edges are held open a predetermined width.

Abstract: This invention minimizes the space required for a speaker system for a multimedia personal computer display on a desktop. The speaker system has a very thin shape, moderate cost, very good impulse and phase response for a crisp sonic detail and good directionality for use by a single listener seated in front of the multimedia personal computer display without disturbing others nearby. Each component of the speaker system is attached to or incorporated in the right or left side of the computer display. Each component comprises a plurality of small speakers arranged in a vertical, linear array. Preferably, each plurality includes a small folded waveguide which is acoustically coupled to the rear of each of the speakers. The folded waveguide is in a unique sheet configuration and enables directional ports in a treble component and a folded variable impedance maze in a base waveguide. The speaker system provides the required shape, clarity and listener isolation needed in the personal multimedia market.

Abstract: This loudspeaker system intended primarily for woofers includes an enclosure (10) and a plurality of loudspeakers (16), each loudspeaker including a driver (18) having an axis, with the loudspeakers (16) being mounted in the enclosure (10) such that the axes of the drivers are arranged relative to each other to neutralize the vibration of the speakers.

Abstract: A method and apparatus for stereophonic reproduction uses conventional left and right stereophonic signals to energize a point source transducer in a complementary manner. The resultant interference sound pattern is interpreted by the brain of a listener to enable the listener to experience stereophonic hearing in a wide region surrounding the transducer, not just in the region of the plane of symmetry. A point source transducer may be simulated by a plurality of transducers positioned with the spacing therebetween less than a determinable maximum distance. While conventional stereophonic signals may be employed in the reproduction of sound, improved reproduction is obtained by producing the signals by recording sound with a pair of microphones arranged with the apogees of their respective field of polar response patterns facing substantially at 180.degree. to one another.

Abstract: A modification and addition to the prior art type of multiple driver push-pull loudspeaker system for subwoofer, bass, or lower midrange frequencies, which prior system is able to reduce the even-order push-pull out-of-phase driver-produced 2nd, 4th, etc. distortion harmonics by the order of 15 to 25 dB in the radiated sound waves. The present invention reduces the important remaining in-phase distortion harmonics using outputs of sensors mounted on the voice coils of each driver to generate electrical signals which are processed and used to substantially lower the remaining in-phase distortion with feedback through a single signal amplifier chain. The present invention contributes from 15 to 30 dB of in-phase distortion reduction of odd-order harmonics and, at relatively high sound power levels only, also reduces some in-phase, relatively lower level, even-order distortion.

Abstract: An audio crossover system having two crossover networks, one suited to the auditory preferences of women and the other to the auditory preferences of men. The former attenuates mid-range frequencies more than high-range frequencies and attenuates low-range frequencies still more. The latter attenuates mid-range frequencies more than low-range frequencies and attentuates high-range frequencies even more than those in the mid-range.

Abstract: The devices proposed improve low-frequency sound reproduction in loudspeaker systems using acoustically closed loudspeaker housings. In particular, the devices permit the use of loudspeaker housings with very much smaller dimensional volumes but with large-area loudspeakers. The devices proposed operate utilizing pressure control in closed loudspeaker housings. This pressure control decreases differences between the gas pressure in the interior of the housing and the time-averaged mean gas pressure outside the housing. The control circuit comprises a pressure sensor, a control unit, a power amplifier and an electrodynamic transducer.

Abstract: A loudspeaker apparatus includes an elongated hollow tube having two open ends, which tube may be a rigid or telescoping tube, and has a wide range speaker mounted at each end of the hollow tube. A pair of deflector surfaces may be flat, polymer surfaces mounted to a base and are positioned at an angle facing each speaker at each end of the tube for deflecting the sound waves emanating from each speaker in accordance with the positioning of the tube. The tube may also have a tuned port formed into the side of the tube and connected to an arcuate passageway built into the hollow portion of the inside of the tube for producing a bass resonance from the backwaves of both speakers.

Abstract: A loudspeaker system overcomes disadvantages of prior art systems. To adjust for undesirable room acoustics, high frequency slope compensation is provided which reaches its plateau well beyond the highest audible frequency, providing a more accurate audio reproduction. Electronic filtering increases the high frequency components beyond the audible range, to drive a single set of high frequency acoustical drivers to properly compensate for high frequency attenuation due to room acoustics. Alternatively, a dedicated high frequency acoustical driver provides the high frequency emphasis to compensate for room acoustics, with another set of high frequency acoustical drivers accurately reproducing the audio signal.

Abstract: The housings of the devices are divided by inner walls into two or three inner chambers. One of the inner chambers adjoins the membrane of the loudspeaker. Adjoining this inner chamber a membrane is built into an opening of an inner wall. Movements of the inner membrane, which are caused by pressure changes in this chamber, are servo supported by an inner electrodynamic transducer, whose membrane lies parallel behind the other inner membrane. The supporting movements are caused by a controller, which tries to hold constant the distance between the two inner membranes.