CH680966A5 - Bass response improving device for closed housing loudspeaker - Google Patents

Bass response improving device for closed housing loudspeaker Download PDF

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Publication number
CH680966A5
CH680966A5 CH118790A CH118790A CH680966A5 CH 680966 A5 CH680966 A5 CH 680966A5 CH 118790 A CH118790 A CH 118790A CH 118790 A CH118790 A CH 118790A CH 680966 A5 CH680966 A5 CH 680966A5
Authority
CH
Switzerland
Prior art keywords
gas pressure
controller
housing
membrane
loudspeaker
Prior art date
Application number
CH118790A
Other languages
German (de)
Inventor
Maximilian Hobelsberger
Original Assignee
Maximilian Hobelsberger
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 Maximilian Hobelsberger filed Critical Maximilian Hobelsberger
Priority to CH118790A priority Critical patent/CH680966A5/en
Priority to PCT/CH1991/000060 priority patent/WO1991015933A1/en
Priority to CA002060661A priority patent/CA2060661C/en
Priority to US07/776,426 priority patent/US5461676A/en
Priority to AT91905477T priority patent/ATE146328T1/en
Priority to DE59108406T priority patent/DE59108406D1/en
Priority to EP91905477A priority patent/EP0476082B1/en
Publication of CH680966A5 publication Critical patent/CH680966A5/en

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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
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • H04R1/28—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
    • H04R1/2807—Enclosures comprising vibrating or resonating arrangements
    • H04R1/2838—Enclosures comprising vibrating or resonating arrangements of the bandpass type
    • H04R1/2842—Enclosures comprising vibrating or resonating arrangements of the bandpass type for loudspeaker transducers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • H04R1/227—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only  using transducers reproducing the same frequency band
    • 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

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Circuit For Audible Band Transducer (AREA)

Abstract

The loudspeaker (LA) is in a fully enclosed cabinet (G) of interior volume (VI). A pressure control circuit decreases the differences between the gas presence in interior (VI) of the housing (G) and the time averaged mean gas pressure, outside the housing. In particular, the control circuit comprises a pressure sensor (P), control unit (R), power amplifier (A) and an electro dynamic transducer (TR).

Description

1 1

CH 680 966 A5 CH 680 966 A5

2 2nd

Beschreibung description

Stand der Technik. State of the art.

Bei herkömmlichen Lautsprechersystemen mit akustisch geschlossenen Lautsprechergehäusen stellt sich das Problem, dass ein kleines Gehäusevolumen die Tieftonwiedergabe stark beeinträchtigt. Bei einem kleinen Gehäuse beeinträchtigen Gasdruckkräfte, die durch Veränderung des Innenvolumens entstehen, die Bewegung der schallabstrahlenden Lautsprechermembran. Die Veränderungen des Innenvolumens werden durch die Bewegungen der Membran verursacht. Die entstehenden Druckkräfte behindern die Auslenkung der Membran und erhöhen als Federkräfte die Resonanzfrequenz und die Güte des Systems. With conventional loudspeaker systems with acoustically closed loudspeaker housings, the problem arises that a small housing volume greatly impairs the bass reproduction. In the case of a small housing, gas pressure forces caused by changes in the internal volume affect the movement of the sound-emitting loudspeaker diaphragm. The changes in the internal volume are caused by the movements of the membrane. The resulting pressure forces hinder the deflection of the membrane and, as spring forces, increase the resonance frequency and the quality of the system.

Um eine gute Tieftonwiedergabe zu erzielen, werden daher entweder unhandlich grosse Gehäuse verwendet, oder es werden die elektrischen Signale, die die Lautsprecher treiben, korrigierend beeinflusse oder es werden die abstrahlenden Lautsprechermembranen direkt in korrigierende Regelkreise eingebunden. Die beiden letzteren Massnahmen verursachen selbst wiederum akustische Verfälschungen, insbesondere das Impulsverhalten wird beeinträchtigt. In order to achieve good low-frequency reproduction, unwieldy housings are either used, or the electrical signals that drive the loudspeakers are corrected, or the radiating loudspeaker membranes are directly integrated into corrective control loops. The latter two measures themselves cause acoustic falsifications, in particular impulse behavior is impaired.

Weiters sind Verfahren bekannt (Tiefenbrun; US-Pat. 4 008 374), die durch Einwirkung einer innenliegenden Lautsprechermembran eine wirkungs-mässige Vergrösserung des Innenvolumens des Gehäuses erzielen. Bei diesem Verfahren wird jedoch das Problem auf den innenliegenden Lautsprecher verlagert. Um gute Ergebnisse zu erzielen, sind wiederum grosse Volumina erforderlich. Ausserdem entstehen Verzerrungen durch Phasenunterschiede in den Bewegungen der beiden Lautsprechermembranen und durch Laufzeiten. Furthermore, methods are known (Tiefenbrun; US Pat. 4,008,374) which achieve an effective enlargement of the interior volume of the housing by the action of an internal speaker membrane. With this method, however, the problem is shifted to the internal speaker. Large volumes are required to achieve good results. In addition, distortions arise due to phase differences in the movements of the two loudspeaker diaphragms and due to transit times.

Die Erfindung gemäss den Ansprüchen ermöglicht eine weitgehend unbehinderte Tieftonwiedergabe bei Verwendung kleiner Gehäuse und grossflächiger Lautsprecher, wobei eine direkte Beeinflussung der abstrahlenden Lautsprecher oder der sie treibenden Signale nicht vorgenommen wird. The invention according to the claims enables largely unimpeded low-frequency reproduction when using small housings and large-area loudspeakers, the radiating loudspeakers or the signals driving them not being directly influenced.

Die gestellte Aufgabe wird durch die Vorrichtung gemäss Anspruch 1 gelöst. Die Vorrichtung zeichnet sich dadurch aus, dass die von den Auslenkungen der abstrahlenden Lautsprechermembran durch Änderungen des Innenvolumens verursachten Differenzen zwischen dem Gasdruck im Gehäuseinneren und dem zeitlich gemitteten Gasdruck im Aussenraum des Gehäuses durch die Wirkung eines Regelkreises stark verringert werden. The object is achieved by the device according to claim 1. The device is characterized in that the differences between the gas pressure inside the housing and the time-averaged gas pressure in the outside space of the housing caused by the deflections of the radiating loudspeaker membrane due to changes in the internal volume are greatly reduced by the action of a control circuit.

Unterschiede zwischen dem Innendruck und dem Aussendruck werden mittels Gasdrucksensoren er-fasst und durch die Wirkung einer Druckregelung vermindert. Diese Verminderung der Druckdifferenz erfolgt durch die Bewegungen einer an das Innenvolumen angrenzenden Membran eines innerhalb des Gehäuses angeordneten elektrodynamischen Wandlers, der als Glied eines Regelkreises arbeitet. Ein Regler verarbeitet das elektrische Signal, das die Druckunterschiede beschreibt. Mittels eines nachgeschalteten Leistungsverstärkers regt der Regler die Membran des innenliegenden elektrodynamischen Wandlers zu Bewegungen an, die die auftretenden Druckunterschiede stark verringern. Als Regler wird vorzugsweise ein PI-, ein PID- oder ein Zustandsregler verwendet. Der Zu-standsregler verarbeitet alle relevanten Druck-grössen, zusätzlich die Zustandsgrössen der innenliegenden Membran, wie Auslenkung, Geschwindigkeit und Beschleunigung. Differences between the internal pressure and the external pressure are recorded by means of gas pressure sensors and reduced by the effect of pressure regulation. This pressure difference is reduced by the movements of a membrane adjacent to the internal volume of an electrodynamic transducer arranged inside the housing, which works as a member of a control loop. A controller processes the electrical signal, which describes the pressure differences. Using a downstream power amplifier, the controller stimulates the membrane of the internal electrodynamic converter to make movements that greatly reduce the pressure differences that occur. A PI, a PID or a status controller is preferably used as the controller. The state controller processes all relevant pressure variables, in addition the state variables of the internal membrane, such as deflection, speed and acceleration.

Beschreibung der Zeichnung. Description of the drawing.

Die Figur zeigt die Vorrichtung gemäss Anspruch 1. Der Aussenlautsprecher LA wird direkt durch das Eingangssignal e(t) angetrieben. Der elektrodynamische Wandler TR ist in eine Regelschleife eingebunden, die weiters aus dem Drucksensor P, dem Subtrahierglied D, dem Regler R und dem Leistungsverstärker A besteht. Dem Subtrahierglied wird als Sollwert ein Signal zugeführt, das proportional dem zeitlichen Mittelwert des Aussendruckes ist. Die Zeitdauer der Mittelwertsbildung ist dabei gross im Vergleich zur längsten Signalperiode, z. B. 100 Sekunden. Am invertierenden Eingang des Subtrahiergliedes wird das dem Gasdruck im Innenraum V1 proportionale Ausgangssignal des Sensors P angelegt. Der Regler ist so bemessen, dass die Regelabweichung, und somit die Druckdifferenz, möglichst klein gehalten wird. The figure shows the device according to claim 1. The external loudspeaker LA is driven directly by the input signal e (t). The electrodynamic converter TR is integrated in a control loop, which further consists of the pressure sensor P, the subtractor D, the controller R and the power amplifier A. A signal is supplied to the subtractor as a setpoint, which signal is proportional to the time average of the external pressure. The duration of the averaging is long compared to the longest signal period, e.g. B. 100 seconds. The output signal of the sensor P, which is proportional to the gas pressure in the interior V1, is applied to the inverting input of the subtractor. The controller is dimensioned in such a way that the control deviation, and thus the pressure difference, is kept as small as possible.

Claims (2)

PatentansprücheClaims 1. Vorrichtung zur Verbesserung der Tieftonwiedergabe bei einem mit einem akustisch geschlossenen Gehäuse arbeitenden Lautsprechersystem, bei dem das Innenvolumen des Gehäuses durch eine innere, akustisch trennende Wand in zwei Teilvolumina getrennt ist, wobei ein Volumen an die Membran des in den das Gehäuse umgebenden Aussenraum Schall abstrahlenden Lautsprechers angrenzt, und bei der ein elektrodynamischer Wandler (TR) so in die innere Trennwand eingebaut ist, dass die beiden Innenvolumina (V1, V2) durch die Membran des Wandlers voneinander getrennt werden, und dass die Membran durch ihre Bewegung auf beide Volumina druck- und volumenändernd einwirkt, und wobei innerhalb des an die Membran des in den Aussenraum Schall abstrahlenden Lautsprechers (LA) angrenzenden Innenvolumens (V1) ein Gasdrucksensor (P) angeordnet ist, der ein den Gasdruck im Innenvolumen beschreibendes, elektrisches Signal erzeugt, dadurch gekennzeichnet, dass der Gasdrucksensor als Glied eines Regelkreises arbeitet, dass der innenliegende elektrodynamische Wandler (TR) ebenfalls ein Teil dieses Regelkreises ist, dass dieser Regelkreis weiters aus einem Regler (R) und einem Leistungsverstärker (A) besteht, dass das Ausgangssignal des Gasdrucksensors dem Regler als ein den Istwert des Gasdruckes beschreibendes Signal zugeführt wird, dass dem Regler als Sollwert ein den zeitlichen Mittelwert des ausserhalb des Gehäuses herrschenden Gasdruckes beschreibendes Signal zugeführt wird, dass der Regier den Leistungsverstärker ansteuert und dieser den innenliegenden Wandler (TR) treibt, und dass der Regler und die übrigen Glieder des Regelkrei-1. Device for improving the low-frequency reproduction in a loudspeaker system working with an acoustically closed housing, in which the inner volume of the housing is separated into two partial volumes by an inner, acoustically separating wall, with a volume to the membrane of the outside space surrounding the housing radiating speaker, and in which an electrodynamic transducer (TR) is built into the inner partition wall so that the two inner volumes (V1, V2) are separated from each other by the membrane of the transducer, and that the membrane presses on both volumes by their movement - and acts to change the volume, and a gas pressure sensor (P) is arranged within the inner volume (V1) adjacent to the membrane of the loudspeaker (LA) emitting sound into the outside space, which produces an electrical signal describing the gas pressure in the inner volume, characterized in that that the gas pressure sensor ar as a member of a control loop ensures that the internal electrodynamic converter (TR) is also part of this control loop, that this control loop also consists of a controller (R) and a power amplifier (A), that the output signal of the gas pressure sensor is sent to the controller as a signal describing the actual value of the gas pressure that the controller is supplied with a signal describing the time average of the gas pressure prevailing outside the housing, that the controller controls the power amplifier and drives the internal converter (TR), and that the controller and the other elements of the control loop 55 1010th 1515 2020th 2525th 3030th 3535 4040 4545 5050 5555 6060 6565 2. Vorrichtung gemäss Anspruch 1, dadurch gekennzeichnet, dass als Regler ein PI-, ein PID-oder ein Zustandsregler verwendet wird.2. Device according to claim 1, characterized in that a PI, a PID or a status controller is used as the controller. 55 1010th 1515 2020th 2525th 3030th 3535 4040 4545 5050 5555 6060 6565 33rd 22nd 33rd CH 680 966 A5CH 680 966 A5 ses derartig dimensioniert sind, dass die Differenz zwischen dem Momentanwert des Gasdruckes in dem an die Membran des in den Aussenraum abstrahlenden Lautsprechers angrenzenden Innenvolumens (V1) und dem zeitlichen Mittelwert des ausserhalb des Lautsprechergehäuses herrschenden Gasdruckes durch die Wirkung des Regelkreises immer annähernd verschwindet und somit der Momentanwert des Innendruckes dem Mittelwert des Aussendruckes immer annähernd gleicht.ses are dimensioned such that the difference between the instantaneous value of the gas pressure in the inner volume (V1) adjacent to the membrane of the loudspeaker radiating into the outside space and the mean time value of the gas pressure prevailing outside the loudspeaker housing always disappears due to the effect of the control loop, and thus the The instantaneous value of the internal pressure always approximates the mean value of the external pressure.
CH118790A 1990-04-09 1990-04-09 Bass response improving device for closed housing loudspeaker CH680966A5 (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
CH118790A CH680966A5 (en) 1990-04-09 1990-04-09 Bass response improving device for closed housing loudspeaker
PCT/CH1991/000060 WO1991015933A1 (en) 1990-04-09 1991-03-15 Device for improving bass reproduction in loudspeaker systems with closed housings
CA002060661A CA2060661C (en) 1990-04-09 1991-03-15 Device for improving bass reproduction in loudspeaker systems with closed housing
US07/776,426 US5461676A (en) 1990-04-09 1991-03-15 Device for improving bass reproduction in loudspeaker system with closed housings
AT91905477T ATE146328T1 (en) 1990-04-09 1991-03-15 DEVICE FOR IMPROVING BASS REPRODUCTION IN SPEAKER SYSTEMS WITH CLOSED ENCLOSURES
DE59108406T DE59108406D1 (en) 1990-04-09 1991-03-15 DEVICE FOR IMPROVING THE BASS REPLACEMENT IN SPEAKER SYSTEMS WITH CLOSED HOUSINGS
EP91905477A EP0476082B1 (en) 1990-04-09 1991-03-15 Device for improving bass reproduction in loudspeaker systems with closed housings

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH118790A CH680966A5 (en) 1990-04-09 1990-04-09 Bass response improving device for closed housing loudspeaker

Publications (1)

Publication Number Publication Date
CH680966A5 true CH680966A5 (en) 1992-12-15

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Family Applications (1)

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CH118790A CH680966A5 (en) 1990-04-09 1990-04-09 Bass response improving device for closed housing loudspeaker

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2050304B1 (en) * 2006-08-10 2018-10-24 Claudio Lastrucci Improvements to systems for acoustic diffusion

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2050304B1 (en) * 2006-08-10 2018-10-24 Claudio Lastrucci Improvements to systems for acoustic diffusion

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