WO1995025413A1 - Dispositif et procede d'adaptation de haut-parleurs a amortissement automatique - Google Patents

Dispositif et procede d'adaptation de haut-parleurs a amortissement automatique Download PDF

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Publication number
WO1995025413A1
WO1995025413A1 PCT/CA1994/000153 CA9400153W WO9525413A1 WO 1995025413 A1 WO1995025413 A1 WO 1995025413A1 CA 9400153 W CA9400153 W CA 9400153W WO 9525413 A1 WO9525413 A1 WO 9525413A1
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WO
WIPO (PCT)
Prior art keywords
coil
damping
matching
speaker
input
Prior art date
Application number
PCT/CA1994/000153
Other languages
English (en)
Inventor
Vladimir Walter Kukurudza
Original Assignee
Vladimir Walter Kukurudza
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Vladimir Walter Kukurudza filed Critical Vladimir Walter Kukurudza
Priority to EP94908926A priority Critical patent/EP0761074B1/fr
Priority to DE69410829T priority patent/DE69410829D1/de
Priority to AU62005/94A priority patent/AU6200594A/en
Priority to PCT/CA1994/000153 priority patent/WO1995025413A1/fr
Priority to CA002192163A priority patent/CA2192163C/fr
Publication of WO1995025413A1 publication Critical patent/WO1995025413A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H04R3/002—Damping circuit arrangements for transducers, e.g. motional feedback circuits

Definitions

  • the invention relates to loudspeakers, and in particular to a damping circuit for use in association with loudspeakers and, in particular, to a self-damping crossover circuit for use in multi-speaker audio systems.
  • These speakers will include a speaker to cover the high frequency high notes (tweeter) and a speaker to cover the low frequency bass notes (woofer) , and in most cases, a speaker to cover the mid-range frequency notes (mid- range) . In some cases there may be multiple speakers for each range. It is customary in such multi-speaker systems to provide one or more filter circuits known as "crossovers" in which the signals for the various ranges are separated so that they are reproduced in the appropriate speakers in the system. Such crossovers incorporate one or more crossover coils as part of the filter circuit. The precise causes of the type of distortion described above are not entirely clear, however, it seems reasonable to assume that one source is the collapsing of the magnetic fields created around the crossover coil during the passage of audio signals.
  • the present invention finds its application both to single speakers and to such crossover circuits so that a damping effect is provided over a part of the frequency ranges or indeed all of the frequency ranges to damp out distortion.
  • crossover circuits inherently incorporate some form of coils, of varying inductances, whereby signals may be divided up into groups or bands of selected wavelengths for reproduction in the different speakers. It is, of course, well known that the passing of electrical current wave forms through a coil will result in the development of transient electromagnetic fields around the coil itself. As the current fluctuates, so also does the induced electromagnetic field. The fluctuation of the induced electromagnetic field is believed to induce, in turn, a fluctuating voltage across the coil which is passed through the speaker coil producing a further unwanted movement and hence sound waves from the speaker. It is believed that this is a major cause of the distortions or so-called "rumble" which can be heard in speaker systems and this distortion is generally considered to be undesirable by the great majority of listeners.
  • the speakers will be of the moving coil type. Such speakers inherently incorporate their own integral coil means. Such speaker coils will in themselves develop a back EMF, induced as the voice coil moves through the magnetic field of the permanent magnet which surrounds the voice coil. This factor is a "given” in almost all speaker systems, and may also be, in itself, a cause of distortion.
  • the invention comprises a damping circuit means comprising matching coil means defining matching coil input and output connection means, with said matching coil output connection means connectable with said speaker input connection means, damping coil means defining damping coil input and output connection means, with said damping coil input connection means connectable to said speaker output connection means, and said matching and damping coil means being wound together on a common support with the turns of one coil alternating with the turns of the other coil, with their said input connection means adjacent one another and their said output connection means adjacent one another whereby currents will flow through said matching and damping coil means in the same direction and whereby transient signals in a respective first one of said matching and damping coils set up magnetic fields around the common support which fields then induce out of phase transient signals in the respective second of said matching and damping coils, said induced out of phase transient signals acting to reduce in strength, or damp, the initial transient signals.
  • the invention further comprises a method of damping audio signals in a speaker system, by passing the same through a damping circuit means, the damping circuit means having matching coil means and damping coil means, said matching and damping coil means each having a first coil end and a second coil end, and having respective input and output connection means, said matching coil means and damping coil means being wound together about a common support and having respective input connection means at coincident first coil end, and having respective output connection means at respective coincident second coil end; said matching coil means and damping coil means being wound in a manner to provide unity coefficient of coupling between said matching and damping coil means, said matching coil connected in series with a coil driven speaker having input connection means and output connection means, with said matching coil output connection means being connected to the input connection means of the loudspeaker and, said damping coil means being connected in series with the same coil driven loudspeaker, and having speaker output connection means connected to damping coil input connection means in such a manner as to provide a continuous circuit between the matching coil input connection means and the damping coil output connection
  • a further feature is that said matching coil may be of a first predetermined inductance and said damping coil may be of a second predetermined inductance different from said matching coil means.
  • variable means may be provided for varying the inductance of one of the matching and damping coils relative to the other.
  • a further feature is such a speaker system wherein there are at least, high frequency speaker means and low frequency speaker means, and incorporating a first high frequency damping circuit for said high frequency speaker means and further a low frequency damping circuit for said low frequency speaker means.
  • a further feature is such a system wherein there are at least three separate speakers in each speaker system, and there being respective damping circuit for said speakers in said speaker system.
  • the matching and damping coils are preferably formed with equal numbers of turns or windings in each coil, with the individual turns of one coil be separated by the individual turns of the other coil, wound on a common support. There are several layers of windings with the turns of one coil in one winding layer overlying the turns of the other coil in the next adjacent winding layer.
  • FIG. 1 is an electrical circuit diagram showing a single damping circuit in accordance with the invention for application to a single speaker;
  • Figure 2 is a detail of the bifilar winding of the matching coil and the damping coil of the invention;
  • Figure 3 is a side elevation of Figure 2, partially cut away;
  • Figure 4 is an electrical circuit diagram illustrating a typical audio loudspeaker system comprising a plurality of speakers and showing damping circuits according to the invention;
  • Figure 5 is an electrical circuit diagram showing a damping circuit according to the invention provided with a variable tapping on the windings of the damping coil means whereby the inductance of that coil may be changed;
  • Figure 6 is a diagram showing a further preferred embodiment for two speakers
  • Figure 7 is a diagram showing a further preferred embodiment for three speakers.
  • a speaker system comprising a single speaker 10 having an integral voice coil 12 and speaker input connection means 14 and speaker output connection means 16.
  • the damping circuit 18 has a matching 20 coil and a damping 22, coil each having respective input connection means 24, 26 and having respective output connection means 28, 30.
  • Matching coil 20 and damping coil 22 are wound in a mode known as "unity coefficient of coupling", in bifilar style i.e. two conductors of the same or very nearly the same thickness placed adjacent one another and wound on a common support as illustrated in Figure 2 and 3.
  • the matching and damping coils are preferably formed with equal numbers of turns or windings in each coil, with the individual turns of one coil being separated by the individual turns of the other coil, wound on a common support. There are several layers of windings with the turns of one coil in one winding layer overlying the turns of the other coil in the next adjacent winding layer.
  • matching and damping coils 20, 22 are wound about a common support 36.
  • Common support 36 maybe for example, a bobbin, of plastic or the like ( Figures 2 & 3) , having non-magnetic properties, or in some cases may be formed of iron-steel, nickel-steel, or any other core which may be advantageous in a given situation.
  • the turns of coil 20, where they are cut away are shown with speckle hatching.
  • the turns of coil 22 are shown with diagonal line hatching. It will be seen that the turns of coil 22 in one winding layer, overlay the turns of coil 20 in the next adjacent winding layer, and so on.
  • Figure 3 also illustrates the two ends of the coil 20, adjacent to the two ends to the coil 22.
  • the two adjacent ends would constitute the input of the two coils and the other two adjacent ends would constitute the output of the two coils.
  • the driving circuit will supply power via the input 32 which is connected to matching coil input connection means 24.
  • Matching coil output connection means 28 is connected to speaker input connection means 14 and power passes through integral voice coil 12 to speaker output connection means 16. Power then flows from speaker output connection means 16 to damping coil input connection means 26, through damping coil 22 to damping coil output connection means 30 from whence it passes to the negative side of the driving circuit 34.
  • the damping circuit as herein described relies on induced currents to function. As a signal is fed into the circuit moving first through the matching coil, a very nearly equal current is induced in the damping coil. The current induced in the damping coil would, however, be approximately 180 degrees out of phase with that passing through the matching coil if the coils were merely shorted out. In other words, the two currents, when added, would very nearly cancel one another. If the speaker was removed from the damping circuit, and a current was applied with a measuring instrument such as a galvanometer connected between the coil output connection means, there would be a very limited electrical potential measured.
  • a measuring instrument such as a galvanometer connected between the coil output connection means
  • the first is the primary signal or applied voltage.
  • the second is the induced current created by the passage of the primary current through the standard cross-over coil, believed to be one source of noise or distortion.
  • the third is the "back EMF" produced in the voice coil of the loudspeaker, believed to be another source of noise or distortion. It is believed that the design of the present damping circuit provides, for each of the second and third unwanted noise signals in the circuit, a very nearly equally strong signal which is 90 degrees out of phase with the respective noise signals. Furthermore the damping coil provides a magnetic braking effort on the voice coil of the speaker.
  • the invention further comprises a method of damping audio signals in a speaker system, by passing the same through a damping circuit means, said damping circuit means comprising matching coil means and damping coil means, said matching and damping coil means each having a first coil end and a second coil end, and having respective input and output connection means, said matching coil means and damping coil means being wound together about a common support and having respective input connection means at coincident first coil end, and having respective output connection means at respective coincident second coil end; said matching coil means and damping coil means being wound in a manner to provide unity coefficient of coupling between said matching and damping coil means, said matching coil connected in series with a coil driven speaker having input connection means and output connection means, with said matching coil output connection means connected to the input connection means of the loudspeaker, said damping coil means being connected in series with the same coil driven loudspeak
  • Figure 4 shows the invention in a system having three separate speakers, namely, a low frequency speaker 38, a mid-range frequency speaker 40, and a high range frequency speaker 42.
  • Each of the speakers is of the moving coil type, and the speakers are together intended to handle the entire audible range of sound waves, with, in most cases, a certain degree of overlap between the adjacent speakers, in a manner well known in the art and requiring no description.
  • Low range frequency speaker 38 has an input 44 and an output 46, indicated respectively as positive and negative.
  • the mid range speaker 40 has an input connection 48 and an output connection 50 indicated respectively as positive and negative.
  • the high range frequency speaker 42 has an input connection 52 and an output connection 54 indicated respectively as positive and negative.
  • the speaker system comprising the three speakers 38, 40, and 42 is intended to be connected to a source of audio frequency signals, coming from a suitable source such as some form of sound reproduction device either a disc or tape type device, or for example from a radio receiver, or directly for example from a microphone or series of microphones with amplifiers and other equipment as needed (not shown) . All of these different systems are vary well known in the art and require no further description.
  • crossover circuits The connections for such systems are indicated generally as 56 and 58 being indicated respectively as positive and negative.
  • the connections for such systems are indicated generally as 56 and 58 being indicated respectively as positive and negative.
  • the purpose of the crossover circuits is to filter out or separate the high-frequency, mid-range, and low-frequency signals, so that they are directed to the appropriate speakers for reproduction therein, and are excluded from the other speakers.
  • some small degree of overlap is provided, the exact degree being dependant upon the design of the speakers and the requirements of the system, all as is well known in the art. It will be appreciated that in Figure 4 no such typical prior art crossover circuits are illustrated.
  • low range matching and damping coils 60 and 62 In place of the conventional crossover circuits, there are provided, in this example, low range matching and damping coils 60 and 62, and high range matching and damping coils 64 and 66.
  • Low range matching coil 60 has an input 68 and an output 70 and low range damping coil 62 has an input 72 and an output 74.
  • High range matching coil 64 has an input 76 and an output 78.
  • High range damping coil 66 has an input 80 and an output 82.
  • Each of the respective pairs of coils 60-62 and 64-66 are wound in a bifilar manner concentrically together about respective common supports (indicated generally as 84 and 86) as shown and as described above (Figs 2 and 3) , providing unity coefficient of coupling.
  • Low range matching coil 60 is connected with its input 68 connected to the input side of the driving circuit 56.
  • the output 70 of low range matching coil 60 is connected to the input side 44 of low range speaker 38.
  • the input 72 of low range damping coil 62 is connected to the output 46 of low range speaker 38.
  • the output 74 of low range damping coil 62 is connected to the negative side 58 of the driving circuit.
  • a suitable condenser 88 is incorporated where necessary, in the connection between the output 50 of mid range speaker 40, and the input 44 of low range speaker 38.
  • the input 76 of high range matching coil 64 is connected to the positive side 56 of the driving circuit through condenser 94a.
  • the output 78 of high range matching coil 64 is connected to the input 52 of the high range speaker 42.
  • the input 80 of high range damping coil 66 is connected to the output 54 of the high range speaker 42.
  • the output 82 of the high range damping coil 66 is connected through a condenser 94b to the negative side 58 of the driving circuit.
  • the coils 64 and 66 are wound and connected in the same manner as described in connection with coils 60 and 62, so that currents flow through the respective coils from their respective inputs to their respective outputs, around coils being wound in the same direction.
  • Suitable auxiliary coils 92, and condenser 94c are provided to filter super-sonic transients.
  • Figure 5 is an example of a variant of the damping circuit. It may be desirable for the user to control the inductance of the damping coil, thereby altering the performance of the damping circuit.
  • a series of tappings 11, 13, 15, 17, and 19 are provided along the damping coil. These tappings are connected into multi-position selector switch indicated generally as 21.
  • Selector switch 21 provides a convenient method of altering the connection point of the outlet side 34 of the driving circuit and damping coil 22, thereby altering the number of effective windings of damping coil 22 and hence its inductance. It can be appreciated that damping circuits having variable tappings may be utilised in multi-speaker systems such as those shown in Figure 4, Figures 6 and 7.
  • FIG. 6 is a diagram of a further preferred embodiment of the inventive circuit in a loudspeaker system having two speakers namely a high and middle range frequency speaker 100, and a low range frequency speaker 102.
  • Each speaker is provided with a damping circuit, indicated generally as 104, and 106 arranged, and connected, in the manner described in respect of Figures 1 and 4.
  • capacitors 108, 110 are connected in the circuit to filter unwanted frequencies from respective speakers.
  • FIG. 7 is a diagram of a further preferred embodiment of the inventive circuit in a loudspeaker system having three speakers namely, a high frequency speaker 112, a middle range frequency speaker 114, and a low range frequency speaker 116.
  • Each speaker is provided with a damping circuit, indicated generally as 118, 120, 122 arranged, and connected in the manner described in connection with Figures 1 and 4.
  • capacitors 124, 126, 128, 130 are connected in the circuit to filter unwanted frequencies from respective speakers.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Circuit For Audible Band Transducer (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)

Abstract

Circuit d'amortissement destiné à des systèmes de haut-parleurs du type contenant au moins un haut-parleur comprenant une bobine de haut-parleur, qui comporte des connexions d'entrée et de sortie, et une bobine d'adaptation (20, 60, 64) prévue pour être connectée en série à la connexion d'entrée de la bobine de haut-parleur et une bobine d'amortissement (22, 62, 66) prévue pour être connectée en série à la connexion de sortie de la bobine de haut-parleur. Les bobines d'adaptation et d'amortissement possédent chacune des extrémités respectives d'entrée (24, 26, 68, 72, 76, 80) et de sortie (28, 70, 74, 78, 82) et sont enroulées dans le même sens sur un support commun (36), leurs extrémités d'entrée respectives étant réunies et leurs extrémités de sortie respectives étant également réunies, les spires d'une bobine alternant avec les spires de l'autre bobine et présentant un coefficient unitaire de couplage, de sorte que le courant de signal primaire traverse les deux bobines dans le même sens, ceci ayant pour effet de réduire les signaux de bruit dans la bobine de haut-parleur. On décrit également un système de reproduction des signaux audio et un procédé d'amortissement de la distorsion dans lesquels on utilise ces circuits d'amortissement.
PCT/CA1994/000153 1994-03-17 1994-03-17 Dispositif et procede d'adaptation de haut-parleurs a amortissement automatique WO1995025413A1 (fr)

Priority Applications (5)

Application Number Priority Date Filing Date Title
EP94908926A EP0761074B1 (fr) 1994-03-17 1994-03-17 Dispositif et procede d'adaptation de haut-parleurs a amortissement automatique
DE69410829T DE69410829D1 (de) 1994-03-17 1994-03-17 Verfahren und vorrichtung zur selbstdämpfenden lautsprecheranpassung
AU62005/94A AU6200594A (en) 1994-03-17 1994-03-17 Self-damping speaker matching device and method
PCT/CA1994/000153 WO1995025413A1 (fr) 1994-03-17 1994-03-17 Dispositif et procede d'adaptation de haut-parleurs a amortissement automatique
CA002192163A CA2192163C (fr) 1994-03-17 1994-03-17 Dispositif et procede d'adaptation de haut-parleurs a amortissement automatique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CA1994/000153 WO1995025413A1 (fr) 1994-03-17 1994-03-17 Dispositif et procede d'adaptation de haut-parleurs a amortissement automatique

Publications (1)

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WO1995025413A1 true WO1995025413A1 (fr) 1995-09-21

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PCT/CA1994/000153 WO1995025413A1 (fr) 1994-03-17 1994-03-17 Dispositif et procede d'adaptation de haut-parleurs a amortissement automatique

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EP (1) EP0761074B1 (fr)
AU (1) AU6200594A (fr)
CA (1) CA2192163C (fr)
DE (1) DE69410829D1 (fr)
WO (1) WO1995025413A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998037732A1 (fr) * 1997-02-19 1998-08-27 Vladimir Walter Kukurudza Systeme et procede d'excitation d'un haut-parleur unique
US20140301560A1 (en) * 2010-10-12 2014-10-09 Vladimir Walter Kukurudza Ear canal earbud sound system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2655586C (fr) 2009-02-25 2017-09-05 Vladimir Walter Kukurudza Circuit compact de suppression du bruit pour petits haut-parleurs

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4127889A (en) * 1975-10-31 1978-11-28 Mitsubishi Jukogyo Kabushiki Kaisha Electromagnetic damping mechanism for force motor
US4315102A (en) * 1979-03-21 1982-02-09 Eberbach Steven J Speaker cross-over networks
US4504704A (en) * 1982-08-31 1985-03-12 Pioneer Electronic Corporation Loudspeaker system
US4792868A (en) * 1985-09-30 1988-12-20 Kabushiki Kaisha Toshiba Recording/reproducing device with means for switching inductance of such device for use in a floppy disk apparatus
EP0409429A2 (fr) * 1989-07-19 1991-01-23 Sony Corporation Unité de commande pour haut-parleur
GB2235350A (en) * 1989-08-21 1991-02-27 David Robin Birt Improvements in moving coil loudspeakers

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4127889A (en) * 1975-10-31 1978-11-28 Mitsubishi Jukogyo Kabushiki Kaisha Electromagnetic damping mechanism for force motor
US4315102A (en) * 1979-03-21 1982-02-09 Eberbach Steven J Speaker cross-over networks
US4504704A (en) * 1982-08-31 1985-03-12 Pioneer Electronic Corporation Loudspeaker system
US4792868A (en) * 1985-09-30 1988-12-20 Kabushiki Kaisha Toshiba Recording/reproducing device with means for switching inductance of such device for use in a floppy disk apparatus
EP0409429A2 (fr) * 1989-07-19 1991-01-23 Sony Corporation Unité de commande pour haut-parleur
GB2235350A (en) * 1989-08-21 1991-02-27 David Robin Birt Improvements in moving coil loudspeakers

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998037732A1 (fr) * 1997-02-19 1998-08-27 Vladimir Walter Kukurudza Systeme et procede d'excitation d'un haut-parleur unique
US20140301560A1 (en) * 2010-10-12 2014-10-09 Vladimir Walter Kukurudza Ear canal earbud sound system
US9232295B2 (en) * 2010-10-12 2016-01-05 Vladimir Walter Kukurudza Ear canal ear bud sound system

Also Published As

Publication number Publication date
CA2192163A1 (fr) 1995-09-21
DE69410829D1 (de) 1998-07-09
EP0761074B1 (fr) 1998-06-03
AU6200594A (en) 1995-10-03
CA2192163C (fr) 1999-11-16
EP0761074A1 (fr) 1997-03-12

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