SECTION 2
Title 1
Title 2
Title 3
Title 4

SECTION 3
Title 1
Title 2
Title 3
Title 4
Title 5

SECTION 4
Title 1
Title 2
Title 3
Title 4
Title 5
Title 6

An electromagnetic bipolar loud speaker of the planar type utilizing a vibratable diaphragm having conductors positioned thereon and uniformly distributed over the vibratable area of the diaphragm to interact with a unidirectional, homogeneous magnetic field generated by a coil surrounding the diaphragm. The loud speaker may be made of a number of diaphragms with different sized vibratable areas and with the same conductor orientation thereon with respect to the supporting frame and energizing magnetic field to cover the wide range of frequency responses.

___________________________________________________________

Compensated crossover network

4,198,540
Cizek
April 15, 1980

The signal from the crossover network of an audio output circuit is applied to certain of the audio system's low, middle and high frequency speakers through particular compensation circuits that are associated with the crossover network and the speaker driver coils. These compensation networks include: a resistor-inductor-capacitor sequence of selected values connected across the terminals of a high frequency or other driver whose resonant impedance peak must be compensated to a resistive impedance for optimum crossover; a resistor-capacitor sequence of selected values connected across the terminals of a low frequency or other driver whose inductance must be compensated to a resistive impedance for optimum crossover; and a variable inductor connected in series with one or more of the terminals of any driver where a "roll off" at higher frequency may be desired. The result is more faithful audio reproduction.

___________________________________________________________

Subwoofer system using a passive radiator

A loudspeaker subwoofer system is disclosed which combines signals from more than one audio channel. A single enclosure mounts an active driver for each of a plurality of audio channels, which active drivers are respectively connected to each respective audio channel. A passive radiator loudspeaker is also mounted in the single enclosure. The passive radiator is acoustically coupled to the active drivers and functions as a subwoofer.

4,350,847
Polk
September 21, 1982

__________________________________________________________

Ribbon loudspeaker

4,395,592
Colangelo (MARK LEVINSON)
July 26, 1983

Abstract

A ribbon loudspeaker is suitable for incorporation into a sound reproduction system without additionally requiring a transformer or series resistor. In one form in which the loudspeaker is bi-directional, a sound reproduction ribbon is received in a pair of magnetic gaps formed from a magnetic system employing a single magnet.  Mark Levinson Audio Systems Ltd. (Middletown, CT) 

6,347,149  
Bachmann ,   et al.  February 12, 2002  

6,330,340  
Proni  December 11, 2001  

6,327,371  
Proni  December 4, 2001  

H.S. Knowles

According to the invention, a bass reproduction device is disclosed, with which the sound emission from the membrane (15) to the listening space (38) is carried out solely by way of a displacement volume (37) and at least one sound guidance conduit (34), whose cross section is smaller than the cross section of the membrane (15). A device of this kind has the advantage that for sound emission, only wall surfaces have to be supplied, which merely have to contain the sound guidance conduit(s) (34). The side of the membrane (15) remote from the displacement volume (37) acts on a closed damping volume (30), which can, however, be changed in its size over a great band width. A particularly favorable bass reproduction is achieved if the length of the respective sound guidance conduit (34).ltoreq..lambda./8 of the desired upper cross-over frequency.

6,212,284  
Puls  April 3, 2001  

A dual mode gradient coil system in which amplifiers powered by a single signal source are connected by a switch to a plurality of coils. The switch selectively serves to place the coils in series with said amplifiers placed in parallel for a high change in magnetic field per unit distance or, alternatively, to allow each coil to be driven by a separate amplifier for a high change in magnetic field per unit time.

6,201,395  
Stanley  March 13, 2001  

6,112,847  
Lehman  September 5, 2000  

4,071,112  
Keele, Jr.  January 31, 1978  

4,187,926  
Henricksen ,   et al.  February 12, 1980  

5,526,456  
Heinz  June 11, 1996  

5,163,167  
Heil  November 10, 1992  

A loudspeaker for projecting sound over a listening area having a driver and a horn in which the horn has a coupling portion communicating at an interface with an outwardly flaring portion, the horn forming an elongated slot at the interface and being provided with means for controlling the sound energy along the axis of elongation of the slot, namely a slot which is narrower at one end and flares outwardly to the other end, or a plurality of transverse veins dividing the slot and sound channel.

5,020,630  
Gunness  June 4, 1991  

A high-frequency constant-directivity horn including a relatively large throat driver and a relatively large throat for receiving sound from the driver, further includes a pair of vanes mounted wholly within the throat, respectively above and below the longitudinal axis in a vertical plane, for effectively dividing the throat into three smaller "pseudo horns" for directing and shaping sound waves from the transducer up to the point of termination of the vanes, beyond which the individual wavefronts mix within and fill a slot in a middle section of the horn, forming a coherent wavefront for passage into a front section of the horn and transmission therefrom, substantially free from wave interference and beaming effects.

4,685,532  
Gunness  August 11, 1987  

4,629,029  
Gunness  December 16, 1986  

4,344,504  
Howze  August 17, 1982  

A loudspeaker horn having improving directivity has a pair of smoothly flared vertical sidewalls joined to a pair of smoothly flared horizontal sidewalls. In an exemplary embodiment, one pair of sidewalls is generated as a surface of revolution, with the curvature of the surface being defined by a power series formula. The contour of the remaining pair of sidewalls is also defined by the power series formula, although different constants may be used. The vertical and horizontal sidewalls are separately defined and are substantially congruent at the rectangular or square mouth. In the exemplary embodiment, the gap formed at the back of one of the pairs of sidewalls is connected to the throat formed at the back of the other pair of sidewalls by a connecting section having an arcuate area which monotonically increases from the throat to the gap.

4,308,932  
Keele, Jr.  January 5, 1982 

2,537,141

PW Kipsch  January 9, 1951

4,171,734  
Peveto ,   et al.  October 23, 1979  

P.W.  Klipsch

P.W. Klipsch

A specially designed ribbon for a ribbon loudspeaker is disclosed which prevents ribbon snaking associated with prior art corregated ribbon. The elimination of snaking enables the use of extremely small gaps between the side edges of the ribbon and the magnetic pole pieces which in turn greatly reduce transient distortion of high fidelity sound. Relatively large amplitude corregations are formed within suspended terminal ribbon portions and substantially smaller amplitude corregations are formed within the suspended centralized ribbon portion.

The ribbon-type loudspeaker that has the characteristics of large cooling effect such that electrical input power is increased. The ribbon-type loudspeaker comprises magnet means having plates positioned in facing relation to each other to form a gap therebetween; an electrically conductive diaphragm extended between said plates to complete a magnetic circuit, said diaphragm forming an electric circuit transversely of said magnetic circuit, at least one side of said diaphragm being formed with an electrically insulating layer; and a heat absorbing plate extended between said plates and attached in contacting relation thereto over an extended area, said heat absorbing plate being formed with an electrically insulating layer in facing relation to the electrically insulating layer of the diaphragm.

A ribbon loudspeaker is suitable for incorporation into a sound reproduction system without additionally requiring a transformer or series resistor. In one form in which the loudspeaker is bi-directional, a sound reproduction ribbon is received in a pair of magnetic gaps formed from a magnetic system employing a single magnet.

An audio frequency transducer having a ribbon tweeter with a multiplicity of side-by-side elongate strip-like magnets with elongate spaces therebetween, the confronting sides of the magnets having pole faces of opposite polarity to create intense magnetic fields therebetween, signal-carrying ribbon-like conductors in the intense magnetic field between adjacent magnets vibrating to produce sound output.

The wide-ribbon loudspeaker comprises permanent magnets 1 forming an open magnetic system, a sound ribbon 3 exposed to the field of the permanent magnets. The permanent magnet 1 has an internal chamber 2 accommodating the ribbon 3 disposed in a plane parallel to the magnet axis, the side walls of the permanent magnet having sound apertures 4 communicating the internal chamber 2 with external space. The degree of the uniformity of the magnetic field in the internal chamber of the magnet is sufficient for using a sound ribbon of any width permitted by the magnet size.

A loudspeaker system using ribbon transducer elements wherein the ribbon elements of the high and mid-range transducer units form a plurality of conductive circuits separated by spaces, or cuts, therebetween which have substantially smooth, undulating wave forms. The magnetic circuit return paths thereof are arranged so as to be remote from and out of the transmitting paths of the acoustic signals generated at such units and the surfaces of the magnetic circuit components and a baffle structure associated therewith are shaped to reduce diffraction effects in the acoustic signals therefrom. A woofer ribbon element has a plurality of interconnected conductive circuit regions to form a generally serpentine shaped circuit, which regions are separated by channels, or cuts, each of which has a smooth, undulating wave form.

A ribbon loudspeaker is provided by a first set of three rows of parallel spaced apart magnets disposed on a first plate, a second set of three rows of parallel spaced apart magnets disposed on a second plate, a diaphragm having a U-shaped electric current conductor disposed on one face thereof and means for clamping the diaphragm in a spaced apart and aligned relationship with both said sets of rows of magnets. The conductor is comprised of thin layers of metal of different compositions, preferably formed on the diaphragm by a vapor deposition process to provide a low mass. The base layer is of a metal that will bond with the diaphragm, while the middle layer serves as the main conductor and the surface layer prevents oxidation.

References cited by Inventor:

IEEE Transactions on Parts, Hybrid and Packaging vol. PHP-No. 4, pp. 253-262, Dec. 1975.
"Flat Voice Coils Make Flatter Speakers", Aisberg et al, Radio-Electronics, Jan. 1962, pp. 63-66.

An electrostatic loudspeaker element including a diaphragm positioned between a pair of acoustically transparent wire grid electrode assemblies. In the preferred embodiment, each electrode assembly comprises a flat rectangular frame having a plurality of wire guiding slots on both sides. A wire whose diameter equals the depth of the slots is wound continuously around the frame in a helical pattern, and a dielectric spacer is adhesively attached to the frame across the slots to maintain the critical distance between the wire grid and the diaphragm. The frame is made of a material having a coefficient of thermal expansion equal to the wire.

Assignee: Koss Corporation
A four-way electrostatic speaker system includes four step-up transformers which have their primary windings connected in a series-parallel circuit across an audio signal source. Electrostatic drivers connect to the secondary windings of each step-up transformer and each forms a parallel resonant circuit which is tuned to an audio frequency within the operating range of the electrostatic driver. The impedance reflected into the primary winding of each step-up transformer is such that the attached electrostatic driver predominantly receives frequencies within its operating range. The necessity of a separate crossover network is thus eliminated.

Assignee: Koss Corporation

A power supply for generating polarizing voltages for the drivers on an electrostatic speaker system includes a charging circuit which charges a battery from the applied audio signal. A dc-to-dc converter generates the relatively high polarizing voltages from the battery voltage and it includes an oscillator which generates an alternating voltage to a voltage multiplier circuit. An electronic switch circuit turns the oscillator on when an audio signal is present and turns it off a preselected time interval after the audio signal is removed.

An electrostatic loudspeaker system includes a transformer whose secondary winding is connected to the conductive plates of an electrostatic loudspeaker and whose primary winding is energized by an audio input signal through a frequency response equalizing network which includes an autotransformer winding as well as resistive and capacitive elements. Specifically, the autotransformer winding is connected in parallel with the primary winding, one audio input terminal is directly connected to one end of the autotransformer winding, at least one tap of the autotransformer winding is connected through a resistive element to the other audio input terminal and the other end of the autotransformer winding is connected to the other audio input terminal through a capacitive element.