EP1471498A2 - Sound Pick-up Device, Sound Instrument and Method for Picking-up Sound Vibrations - Google Patents

Abstract

The sound pickup system (30) for the electric cello or guitar consists of piezoelectric membranes (14) with electrical connections (15). The strings (9) of the string instrument press on the upper portion of a bridge (5). The upper portion of the bridge is held on flexible side mountings (13) and a spring-loaded (4) central mounting with flexures on a baseplate (1). Pressure members (7) on arms (11) on the upper bridge bend the piezoelectric membrane to produce electrical signals.

Description

The invention relates to a sound vibration reduction system for converting Sound vibrations of a sound instrument in electrical signals, a sound instrument with such a sound vibration collection system and method for removing sound vibrations from a sound instrument.

• Bei Live-Auftritten vor großem Publikum, im Freien oder bei der Kombination von leisen akustischen Instrumenten mit den beliebig verstärkbaren elekroakustischen Instrumenten muß der Schall der akustischen Instrumente in elektrische Signale gewandelt und nach dem Durchlaufen von Mischpulten und Verstärkern über Lautsprecher wiedergegeben werden. Als Wandler eignen sich Tonabnehmer prinzipiell besser als Mikrofone, da bei Tonabnehmeranordnungen die Rückkopplungsschwelle deutlich höher liegt als bei Mikrofonanordnungen.
• Im Gebiet der Musikaufnahmetechnik und im vorgenannten Anwendungsgebiet ist es häufig wünschenswert, wenn die einzelnen Instrumente über separate Kanäle aufgenommen werden können, um dann über die spätere Signalverarbeitung, etwa an Mischpulten, den Klang und die Lautstärkeverhältnisse abzustimmen. Bei der Aufnahme über einzelne Mikrofone werden hierzu Richtmikrofone und besonders dicht am Schallerzeuger angebrachte Mikrofone eingesetzt. Zum Teil müssen die Einzelinstrumente in schallisolierenden Einzelräumen aufgenommen werden. Beim Einsatz von Tonabnehmersystemen an leisen akustischen Instrumenten würden sich die geschilderten aufwendigen Mikrofonaufnahmeanordnungen erübrigen, da das Übersprechen auf die Mikrofone benachbarter Instrumente vermieden wird.

Sound vibration acceptance systems are used for coupling to structure-borne noise, e.g. B. a musical instrument to convert the removed sound vibrations into electrical signals. These electrical signals are then used with the help of electronic components to amplify the sound or record. In particular, such vibration pickup systems are used as pickups for musical instruments. Use in the following main areas of application would be desirable:

• When performing live in front of a large audience, outdoors or when combining quiet acoustic instruments with the electro-acoustic instruments that can be amplified as required, the sound of the acoustic instruments must be converted into electrical signals and, after passing through mixers and amplifiers, reproduced via loudspeakers. In principle, pickups are better as transducers than microphones, since the feedback threshold for pickup arrangements is significantly higher than for microphone arrangements.
• In the field of music recording technology and in the aforementioned field of application, it is often desirable if the individual instruments can be recorded via separate channels in order to then coordinate the sound and the volume ratios via the later signal processing, for example on mixing consoles. When recording via individual microphones, directional microphones and microphones attached particularly close to the sound generator are used for this purpose. Some of the individual instruments have to be recorded in soundproofed individual rooms. When using pickup systems on quiet acoustic instruments, the elaborate microphone recording arrangements described would be superfluous, since the crosstalk to the microphones of neighboring instruments is avoided.

Known systems, such as. B. in EP 0 840 282 A1 or US 6,255,565 are the structure-borne noise of a stringed instrument with the help of a piezoceramic Foil under the bridge feet of the string instrument or on the strings directly from.

In known systems, the bridge, usually made of wood, takes the string vibrations as mechanical vibrations, transforms and filters them and conducts them over the bridge feet onto a sound floor that further transforms the sound and finally radiates to the environment as airborne sound. Many common pickup systems couple to the structure-borne noise of this bridge. The heart of the Pickup is the transducer that converts the mechanical vibrations into electrical ones Implement vibrations. Path changes in the form of mechanical vibrations are converted into electrical voltage changes by the converter. Such Pickup systems can be in existing or custom-made recesses of the web are inserted or clamped, as in US 4,785,704 is described.

EP 0 609 553 B1 describes a pickup for musical instruments in which Voice coils vibrated by the resonance body of the instrument that reach into the annular gap of a permanent magnet. On the coils the induction voltage generated by the vibrations is tapped. The permanent magnet as a passive pole of movement of the formed in this way Transducer is decoupled by springs.

Other pickup systems are used as an intermediate link between the string-guiding Upper part of the bridge and feet standing on the soundboard executed as described in EP 0 840 282 A1. The structure-borne sound waves traverse the distance between his two poles of movement and experience a phase shift, the relative displacement of the two Poles of motion for the actual change is available.

The object of the present invention is to provide a sound vibration reduction system for converting sound vibrations of a sound instrument into electrical ones Signals, a sound instrument with a sound vibration reduction system and Method of taking sound vibrations for conversion into electrical Specify signals with improved acoustic properties. This task is with a sound vibration system with the features of the claim 1, a sound instrument with the features of claim 19 and Method for sound vibration reduction with the features of claim 24 or 25 reached. Subclaims are directed to preferred designs.

An inventive sound vibration acceptance system for converting Sound vibrations of a sound instrument in electrical signals have at least a mechanical-electrical converter with one active and one passive Movement pole on, the active movement pole with a swinging Element of the sound instrument either directly or via an intermediate one Pass-through element can be brought into contact. At least one inertial mass element is connected to the passive movement pole of the transducer, this inertial mass element is decoupled from vibration with a bearing, which is independent of an existing connection via the converter and the vibrations parallel to the direction of the acoustic vibrations to be reduced decoupled. For reasons of symmetry and because of the easy adaptability to the Geometry z. B. the bridge of a stringed instrument are advantageously two transducers and two inertial masses are used.

The at least one additional inertial mass element is essentially at rest against the vibration to be picked up, both against the sound vibration pick-up point as well as against other vibrating parts of the Instrument.

In contrast to conventional pickup systems, the invention uses Sound vibration acceptance system one or more transducers, their passive movement pole with independent of the actual transducer Inertial masses are connected separately via vibration-isolating pickup bearings stored in a reference environment at rest are. Inertia masses of at least 20 g are advantageous.

For the purposes of the present text, the bearing is decoupled from vibrations referred to when they are at least in the direction parallel to the direction of the decrease Sound vibrations decouples vibrations.

A sound vibration acceptance system according to the invention has at least an inertial mass with transducer. However, two or more can also be used Inertia masses can be provided with a corresponding number of transducers. Are several Provided transducers with inertial masses, so the transducers can be interconnected to amplify the electrical signal. Depending on whether the Converters in phase or in phase when operating the sound instrument vibrate, the signals become out of phase or in phase with each other switched to achieve an optimal gain result.

With the sound vibration reduction system according to the invention, electrical Output services are provided, which are suitable, analog Line-in inputs of audio devices are normal and non-reactive without intermediate switching controlled by electronic preamplifiers. So z. B. a medium Output voltage greater than 0.25 V with a nominal output impedance of to reach less than 15 kOhm.

On the other hand, it is suitable due to the optimal sound vibration reduction properties of the system according to the invention, the system for sound vibration reduction of quiet instruments, especially of semi-acoustic ones Instruments whose handling corresponds to original acoustic instruments, but which should not emit a loud direct sound. With such semi-acoustic Instruments can e.g. B. Practice concert musicians without being too remote or to rely on soundproofed rooms. Such instruments with a sound vibration acceptance system according to the invention can be in the form Weight, handling and response to the original acoustic instruments correspond as far as possible. The musician can use the largely original Sound z. B. perceive speakers positioned near headphones or near the ears. Nevertheless, the basic playing technique on such a semi-acoustic Instrument correspond to the original instrument.

The sound vibration acceptance system according to the invention is different Instruments can be used, but e.g. B. also as a pickup on a glass pane connectable, which records the sounds and sounds of the environment. Especially However, it is advantageous to use a stringed instrument, e.g. B. one Cello.

Due to the vibration-decoupling property of the inertial masses the side of this bearing facing away from the inertial mass even in immediate Be attached to the sound instrument near the sound vibration pick-up point. To avoid damping the detachable amplitude and influencing the sound to minimize, however, is preferably used as an attachment point place further away from the sound vibration pick-up point with less Natural vibration selected.

It has proven to be particularly advantageous if the modulus of elasticity (or the material stiffness) of the inertial mass element including the connection of the inertial mass element to the passive movement pole of the transducer has a value of at least 20 N / mm ² .

The vibration-decoupling storage preferably has in the direction of Vibration of the sound to be picked up a bearing stiffness of less than (TM / 4) (N / (g · mm)) if the above special storage of the inertial mass is supplemented by additional bearings such as the material composite between the active and passive movement pole in some transducer types, whereby this stiffness includes all the effects supporting the inertial mass. The vibration decoupling Storage has also preferably in the direction of Vibration of the sound to be picked up a bearing stiffness of less than (TM / 8) (N / (g. Mm)) if the above special bearing is the only one represents essential storage of the mass of inertia, as is the case for example can be with converter types without material composite between the active and the passive pole of movement. In both cases, TM stands for the size of the inertial mass in grams. Falling below the stiffness specified above proves to be particularly favorable for the optimal conversion of the sound vibrations in sound-accurate electrical signals, since the mass of inertia and thus the passive movement pole of the transducer particularly effective against the reception of Disturbing sound and phase-shifted useful sound from the direction of the attachment the inertial mass storage is decoupled from the reference environment.

The overall stiffness of the inertial mass is in the direction of useful sound vibration in relation to the mass of inertia in such preferred embodiments so low that the natural frequency of the spring-mass system Values below the hearing threshold can be shifted. So the inertial masses stay on the passive converter poles with low damping and positioning measures stand still throughout the entire transmission range and enable a linear frequency response and maximum effectiveness of the Converter.

An immobility and rigidity of the vibration-decoupling bearing in on the other hand provides the directions transverse to the direction of the useful sound vibration The following advantages: The transverse movements between the transducer and the sound vibration take-off point are reduced and thus noise and possible incorrect positions or mechanical overloads in the converter are avoided. Is the sound vibration tapping point of the sound body designed in such a way that the usable vibration direction in normal use essentially is parallel to the earth's surface, such as B. when installed in the bridge of a cello, then the bearing is designed stiff in the direction of gravity. So she can take static support and the flexible direction of the vibration decoupling Storage remains free for the optimal coupling of the transducers to the Sound vibration acceptance point of the sound instrument. It turns out to be cheap when the vibration-decoupling mounting has a stiffness parallel to Direction of the acoustic vibration to be reduced by at most half the stiffness perpendicular to this direction.

The vibration-decoupling bearing should be in the direction of the one to be removed Be sonic vibration compliant, so a preferred direction of movement in this Direction. This preferred direction should be as little as possible, advantageously at least less than 32 ° from the direction of vibration of the to be removed Sound vibration deviate.

The vibration-decoupling bearing can be a linear guide or a Include curve guidance. The vibration-isolating bearing preferably has at least one joint.

In a particularly advantageous embodiment, the vibration decoupling Storage as a parallelogram guide with at least two articulated arms and four Joints executed. On two opposite sides of this parallelogram guide are those elements that can be moved against each other should. Solid-state joints have proven to be a simple and inexpensive option, especially rubber joints or flex joints. Such solid-state joints can consist of metals or metal components, thermosetting, contain thermoplastic or elastomeric plastics. Likewise, corresponding Joints made of textiles, fiber materials or as composite materials or Compounds of the above components can be executed. Solid joints in particular have the advantage of absolute freedom of play. Both the most common bearing play, on the other hand, can lead to other joint designs disturbing rattling noises, especially certain resonance frequencies, to lead.

To ensure that the torsional rigidity is sufficient in the case of a parallelogram-type mounting To make it high, the distance between two outer advantageously Articulated arms chosen at least half as long as the length of the articulated arms, thus the parallelogram sides parallel to the direction of the vibration to be picked up at least half as long as the parallelogram sides perpendicular to the Direction of the vibration to be picked up. For the same reason the width of the articulated arms is advantageously chosen to be at least half as large become like the length of the articulated arms.

The flexibility of the joints sufficiently high to make towards the abzunehmenden Nutzschalles and shifting despite the antivibration storage or vibrations transmitted towards inaudible low frequencies, the bends in the joints are advantageously at most ¹ / _10th times as thick as the length of the joints ,

The coupling of the transducer assembly to the sound vibration tapping point on the sound instrument z. B. done by pressing. You can do this accordingly Pressure devices, e.g. B. compression springs may be provided. These compression springs can the transducer assembly against a compared to the sound vibration point Support the resting part of the sound instrument. at Such a pressing device is a particularly advantageous embodiment, z. B. compression springs between the articulated arms of the parallelogram Management of the vibration-decoupling bearing inserted.

The pressing device can solid springs, z. B. compression springs or rubber springs, but also have gas springs or magnetic repulsion springs. With appropriate Arrangement on the sound instrument, the pressing device can also Use the weight of the inertial mass.

The active pole of movement of the transducer and the sound vibration tapping point of the sound instrument can be directly connected to each other. Especially Favorable for the sound, however, has been found to be between active Pole of movement of the transducer and the sound vibration take-off point are a pass-through element located in the form of a plunger for transmitting the sound vibrations. This pestle can either be at the sound vibration take-off point and be attached to the active pole of movement of the transducer or only on one of these Elements and on the other of these elements can only be pressed. An embodiment is also possible in which the plunger is only pressed at both points becomes. The pressing can, for. B. in the preferred described above Embodiment with the help of the pressing device.

Such a pass-through element takes over the sound vibrations of the sound vibration take-off point energized and in phase and passes it on as Longitudinal vibrations continue on the active pole of movement of the transducer.

A pass-through element of low mass and high has proven particularly advantageous Proven rigidity relative to its mass. So there are resonance frequencies, which are far above the vibrations to be transmitted, so that the plunger conducts the vibrations linearly and without superposition through natural resonances. Due to a large diameter of the plunger in relation to its Length are bending vibrations as an undesirable additional form of vibration kept low.

Hard elastomeric material is advantageous as material for such a tappet, in particular if the sound vibration tapping point from that for musical instruments typical material is wood. Become the materials of the sound vibration collection point Touching tappet areas selected too hard, it can be particularly difficult high sound amplitudes and sonic rapidities cause the plunger and the active transducer pole no longer vibrates due to inertia can follow and the plunger tip lifts from the sound absorption point. In these In extreme cases, there would be unwanted sound distortion or incorporation of the ram into the sound vibration take-off point. The pestle takes over here So the task of a filter and damper for overdriven portions of the removed Useful noise and the task of protecting against wear and tear or changes the size and pressure distribution of the contact surface between the plunger and Sonic vibration off point. These functions of the plunger guarantee that overdrive distortion is eliminated before conversion in electrical signals and temporal constancy of the sound characteristics.

So that the corner frequency or the corner amplitude for the response of the damping in the range outside the top frequencies to be transmitted or above the greatest volume to be transmitted, it has proven to be advantageous proven to be the sum of the masses on the active transducer side (essentially the mass of the ram and the mass of the vibrating transducer components) to choose particularly small in relation to the sum of the masses on the passive transducer side (essentially the mass of the inertial mass and parts the inertial mass storage).

In the case of a plunger that has at least one loose connection point either with the Sound vibration take-off point of the sound instrument or the active movement pole of the converter has proven to be advantageous if this connection point is designed to be angle-tolerant. This can be achieved that this loose connection point is a cylindrical, spherical or pointed element has and thus rests only with a limited area. With such an arrangement you get a good temporal consistency of the sound results and wins at the same time an element for sound-neutral tolerance compensation for tolerance movements, the z. B. when tuning a stringed instrument or other form or Changes in position caused by bumps and signs of wear. The Cylindrical, spherical or pointed element can either be on the plunger itself or be trained at the sound vibration tapping point.

For the sound, it proves to be advantageous if the contact pressure of the plunger is applied the loose connection point is less than eight times the weight that the Inertia mass and the converter corresponds. It is also advantageous if the loose connection point has a relative sliding friction number of less than 0.3.

As a converter z. B. elements are used, the distance changes using optical methods and effects, or transducers, the one Detect distance-dependent electrical capacity change. There are also converters possible the electrical, magnetic and electromagnetic field changes or capture related effects. Particularly advantageous due to The simple handling and robust, compact design are piezoelectric Elements, in particular a membrane with a piezoelectric ceramic Coating.

The sound vibration acceptance system according to the invention is in contrast to the conventional converter systems also with converters without composite materials can be used between active and passive movement pole. An example of one such a composite material-free converter would be a capacitive converter in which the sound vibration absorption surface is metallized and at a short distance a counter surface divided into two metallized pole halves parallel to this surface is arranged, which is applied to the passive side of the transducer. at Vibration-induced changes in distance change the capacity of the arrangement. This change in capacitance can be achieved using suitable electronic circuits as with the condenser microphones in electrical voltage fluctuations convert.

A sound instrument according to the invention has a sound vibration reduction system according to the invention, which picks up the sound vibrations at at least one sound vibration reduction point, which vibrations are set in motion during operation of the sound instrument. In this case, the sound vibration take-off point can advantageously comprise a swing arm, one end of which has a vibration surface that is connected to the transducer of the sound vibration take-off system according to the invention, the swing arm having an elongated shape. This arm transfers the tapped off Nutzschallschwingungen and is advantageously designed such that at least _{^2/3 of} the arm length are free of voltage conditions, which are due to other mechanical functions of the sound instrument such. B. bending of the bridge during the tuning process of a stringed instrument.

For example, the sound vibration reduction system according to the invention can Replace bridge of a stringed instrument or parts of it. Likewise, the saddle, the tailpiece of a stringed instrument or parts thereof by the invention Sound vibration acceptance system to be replaced.

In other versions of the inventive sound instrument, this couples Sound vibration reduction system according to the invention on the sound floor or on another structure-borne component of the sound instrument, for. B. the saddle, the bass bar or the tuning stick of a stringed instrument. As well can the sound vibration system according to the invention on a string couple directly.

The sound instrument according to the invention can be a normal instrument which with the help of the sound vibration reduction system according to the invention Sound vibrations are picked up and converted into electrical signals become.

A preferred further development of the sound instrument according to the invention is a Instrument that produces little or no direct sound in the audible range. Such semi-acoustic instruments are used e.g. B. by stringed instruments formed with or without a small sound box. The sound vibrations are with Removed with the help of the acoustic vibration acceptance system according to the invention, converted into electrical signals, electronically processed and directly or output via loudspeaker after amplification.

In a method according to the invention for reducing acoustic vibrations the sound vibrations of at least one sound instrument mechanical-electrical converter recorded and converted into electrical signals, the active movement pole of the at least one transducer either directly or via a pass-through element with a sound vibration take-off point a sound instrument is in contact and the passive movement pole with at least one inertial mass element is connected, which in the direction of sound vibration to be decoupled from vibration and from a possibly existing connection via the converter is stored independently.

Figur 1:

eine Schnitt-Draufsicht auf ein erfindungsgemäßes Schallschwingungsabnahmesystem,

Figur 2:

eine perspektivische Schnittansicht eines solchen Schallschwingungsabnahmesystems,

Figur 3:

eine schematische Detailansicht der in Figur 1 bzw. Figur 2 gezeigten Ausführungsform,

Figur 4:

ein erfindungsgemäßes Klanginstrument,

Figur 5:

einen Steg einer anderen Ausführungsform eines erfindungsgemäßen Klanginstrumentes zum Einsatz mit einem erfindungsgemäßen Schallschwingungsabnahmesystem,

Figur 6:

eine Teilansicht einer anderen Ausführungsform eines erfindungsgemäßen Schallschwingungsabnahmesystems, und

Figur 7:

einen Steg einer erfindungsgemäßen Ausführungsform eines Klanginstrumentes zum Einsatz mit einem erfindungsgemäßen Schallschwingungsabnahmesystem der Figur 6.

The invention is explained in detail below using exemplary embodiments with reference to the accompanying figures. It shows:

Figure 1:

2 shows a sectional top view of a sound vibration reduction system according to the invention,

Figure 2:

2 shows a perspective sectional view of such a sound vibration absorption system,

Figure 3:

2 shows a schematic detailed view of the embodiment shown in FIG. 1 or FIG. 2,

Figure 4:

a sound instrument according to the invention,

Figure 5:

a bridge of another embodiment of a sound instrument according to the invention for use with a sound vibration reduction system according to the invention,

Figure 6:

a partial view of another embodiment of a sound vibration reduction system according to the invention, and

Figure 7:

6 shows a bridge of an embodiment of a sound instrument according to the invention for use with a sound vibration reduction system according to the invention from FIG.

FIG. 1 shows the sectional view through a sound vibration reduction system according to the invention, how it z. B. can be used as a replacement for the bridge of a cello can. Figure 2 shows a perspective view of this embodiment. there are usually identical elements for the sake of clarity only once provided with a corresponding reference number.

The entire sound vibration absorption system is designated 30. 1 designated a substructure, which is supported by feet 10 on the sound instrument. On the middle part of the substructure 1 is supported by a support leg 12 of the wooden superstructure 5 from. The strings 9 of the sound instrument are in the string guide notches 18 of the superstructure 5 stored. The superstructure 5 has in this embodiment outer feet 13, which are increasingly slender towards their ends, and at its extreme ends by two clamps, e.g. B. eccentric fittings, are positively and non-positively connected to the substructure 1. The feet are 13 designed such that they are flexible joints due to their slim design represent and the pendulum movement of the superstructure 5 in the direction 21, which further below is described in detail, oppose little resistance, but the necessary restoring force for the pendulum vibrations and the correct global Ensure the position of the superstructure 5 relative to the substructure 1 and the strings 9. By massive jamming of the feet 13 with the resting substructure 1 are annoying Signs of rattling and vibrations on the contact surfaces to the substructure 1 avoided. The metatarsus 12 absorbs the static bearing forces, the Pressing via the installation force and the proximity of the installation point to the node of the pendulum vibrations avoid unwanted vibrations. For example the static contact pressure is caused by the string tension of the strings 9, the the superstructure 5 presses in the direction of the substructure 1, which in turn extends over the Support feet 10 on the body 31 of the instrument (see Figure 4). Thereby, that the outer feet 13 are designed as a bending beam, the middle takes over Foot 12 the static loads that z. B. 250 N to 300 N at a string tension of 4 160 N can be.

At the middle part of the substructure 1 there are vibration decoupling ends in the form of a parallelogram Bearings 3 are provided for the inertial masses 2.

These parallelogram guides are shown schematically in detail in FIG. 3. Articulated arms 42 are fastened to the middle part of the substructure 1 via joints 41. These articulated arms 42 are in turn via joints 41 with the inertial mass elements 2 connected. The articulated arms 42 are, for. B. plastic joints one Length of about 1 cm. The width that is used for the selected representation of the Figures 1 and 3 is measured perpendicular to the plane of the figure, z. B. 1.5 cm. The joints 41 are in the described embodiment with thinned areas a thickness less than 0.1 times the length of the articulated arms. The parallelogram-like Design is so chosen that movement of the inertial mass elements 2 relative to the substructure 1 in direction 22 is easily possible, one Movement perpendicular to this direction is very limited.

Again with reference to Figures 1 to 3 compression springs 4 can be seen, the are introduced between the articulated arms 42, which are biased such that they the inertial mass elements 2 in FIG. 1 upwards against the superstructure 5 Pretension. In Figure 3, these springs are only indicated schematically as a zigzag line.

Located at the area of the inertial mass elements 2 shown in FIG a membrane 14 with a piezoelectric coating. Electrical connections for tapping on the piezoelectric membrane by mechanical Electrical voltage generated are schematically by supply lines 15 shown, the z. B. lead to an electronic evaluation unit.

The inertial mass elements 2 have z. B. a mass of 150 g. The piezoelectric Membrane 14 has a diameter in the preferred embodiment of 27 mm, a thickness of 0.3 mm and is on the inertial mass elements 2nd glued by means of an overlapping ring contact surface of 0.5 mm width.

In the center of the piezoelectric membrane 14 is a plunger element 7 made of hard elastomer Glued on material. There is e.g. B. from a thermoplastic Elastomeric compound. The thickness of this plunger 7 is 1 mm to 2 mm in one Diameter of z. B. 7 mm. The plunger 7 are z. B. simply by Contact pressure of the prestressed compression springs 4 on the superstructure 5.

The end face of the plunger 7 facing the sound vibration absorption surface can have a slightly spherical shape, so that only a very small area, which do not necessarily correspond to the entire end face of the plunger 7 must be in contact with the superstructure 5 at the sound vibration take-off point 8. In the embodiment shown, a complete according to the invention Transducer unit formed from the components tappet 7 and the vibratable Proportion of the converter membrane 14 as components which represent the active movement pole represent the transducer system, and from the no longer vibratable Edge areas 6 of the membrane, the inertial mass 2 and also one effective portion of the mass of the vibration decoupling Inertial mass storage 3, which are the components of the passive movement pole of the converter system.

To forward the useful sound vibrations from the superstructure 5 in the direction of Tappets 7, swing arms 11 are provided. These swing arms do not take over essential static loads. The strings are supported on the strings 9 the midfoot 12. The swing arms 11 have only the task, the sound vibrations with the greatest possible amplitude and the smallest possible damping to the tappets 7 to transfer.

Lateral incisions 16 and central incisions 17 can be provided in the superstructure 5 be similar to conventional bridge instrument bridges Optimize sound transmission. Such incisions 16, 17 make the web more flexible against the pendulum vibrations 21 and secure a position of the pendulum vibration axis near the contact area of the midfoot 12 on the base 1.

FIG. 4 shows an inventive sound instrument with an inventive one Sound vibration pickup system 30. The embodiment is a semi-acoustic Cello with a semi-acoustic body 31, a neck 33 and a spike 34, the z. B. can be designed extendable. To the side of the Semi-acoustic sound body 31 are support elements 32 which, for. B. as Can serve knee support. The semi-acoustic body 31 is not suitable emit loud direct sound like the sound body of a conventional one Cello would be.

When playing on such a violoncello according to the invention Sound vibrations decreased as follows. Brushing, plucking or striking the strings 9 with an arc lead to transverse vibrations in the direction 20. The lateral force generated by the transverse vibration 20 is from the string introduced into the superstructure 5 via the string guide notch 18. There is one Pendulum vibration of the superstructure 5 in direction 21 due to the outward tapered feet 13 that move the lower part of the superstructure 5 in Do not allow direction 20, but a pendulum movement 21 around the midfoot 12 allow. This vibration is applied to the tappets 7 via the swing arms 11 passed on, which in turn is essentially linear to the piezoelectric Transfer membrane 14. The vibration transfer of the two plungers takes place phase opposition. In the electronic postprocessing of the piezoelectric Membranes14 tapped out of phase electrical voltages the signals are interconnected in parallel or in series, so that on the output side either the impedance halved or the voltage level be doubled. The small diameter of the plunger 7 in relation to Diaphragm diameter of the membrane 14 causes only a small lever arm Torsion of the membrane 14 in bending vibrations, so that the initiation undesirable additional forms of vibration is suppressed even more effectively.

The spherical configuration of the plunger 7 in the Support area on superstructure 5, which is a practically identical size and pressurization of the tappet end surface even with slight misalignments between Sound vibration absorption surface 8 and tappet 7 causes.

The vibrations are in the direction 21 via the plunger 7 on the membrane 14 transfer. The passive movement pole 6 of the converter unit described above is in connection with the inertial mass elements 2, the vibration decoupling are stored. The inertial mass elements 2 are essentially at rest against the vibration, which is carried out by the superstructure 5 as well possibly from the soundboard of the sound body 31 on which the feet 10 are supported.

In another embodiment, the compression springs 4 are not in the Parallelogram guides 3 are provided, but support the inertial elements 2 directly against the substructure 1. Such support is such. B. in the embodiment of Figure 6 described below realized.

The described embodiments can replace a web String instrument can be used. Sound vibration reduction systems according to the invention can also run as a separate assembly and to existing ones Saddles, bars or other vibrating surfaces of the instrument coupled become.

Figure 5 shows an alternative embodiment for the superstructure 5. The same elements are again identified by the same reference numerals, with each again only one of the possibly duplicate elements with the Reference number is provided. At the sound vibration tapping points 8 Operation of the plunger 7 with its upper contact surface. In the embodiment 5, the swing arms 11 and the side feet 13 are fused together. Such an embodiment can e.g. B. especially for small superstructures 5 be advantageous since the pickup tappet 7 as far from the Center axis 12 should be placed away to tap large amplitudes to be able to accommodate large inertial mass elements 2. For further notches between the swing arms 11 and the outer feet 13 then there may be no more space. Nevertheless occurs with this tripod arrangement Sound vibration tapping points 8 a high undamped vibration amplitude on. For larger superstructures 5, z. B. on a cello or a double bass, is often sufficient space to close the five-foot arrangement of Figures 1 and 2 realize.

An alternative construction is shown in FIG. This is the web 51 of a bass, which is shown here only as a partial view. Via a clamp 19 of the system on the bridge foot of the bass bridge 51 is only schematic shown bracket 23 attached, the sound vibration reduction system according to the invention supports. Again, via a parallelogram guide 3, the Comprises articulated arms 42 and joints 41, an inertial mass element 2 is held, that is via a compression spring 4 against the bracket 23 on the clamp 19 supports. As already described with reference to FIG. 1 and FIG. 2, this represents Inertial mass element 2 over the edge fastening of the membrane 14 passive movement pole 6, the active movement pole of the piezoelectric Diaphragm 14 is connected to the plunger 7. Figure 6 clearly shows that spherical contact surface of the plunger 7 for contact with the sound vibration take-off point 81st

Figure 7 shows a bass bridge 51 with possible sound vibration removal points 81.82.

Like the reference number 8 in FIGS. 1 to 5, the reference numbers designate here 81 and 82 the contact surfaces between plunger 7 and that part of Superstructure 5, on which the sound vibration is picked up.

Because of the great variability of the sound vibration reduction system according to the invention it is possible to differentiate on the different game postures Instruments to be considerate. Is z. B. a cello vertically put his stinger and be played like this, that's how it is in Figures 1 to 3 Sound vibration reduction system shown in an ideal location aligned such that the preferred direction of movement of the inertial mass storage perpendicular to The direction of gravity is stiff because the total gravity of the inertial masses is stored and no directional component of gravity in the direction of removed sound vibrations and thus in the compliant bearing direction the parallelogram storage runs. Jerky movements of the instrument mass, following gravity does not lead to any undesired deflection the mass of inertia. Nevertheless, with inclinations of the cello z. B. from less than 45 ° the system according to the invention still has advantages since at least one Most of the gravity of the inertial masses is not yet in the direction of deflection the inertial masses acts. In the arrangement of the invention Sound vibration pickup system on the instrument can do this more advantageously Way are taken into account. So a double bass z. B. usually more vertical kept as a cello, so that a sound vibration system according to the Figures 1 to 3 formed substantially perpendicular to the sound body can be used to optimally use the beneficial effect. On the other hand, a violin becomes kept essentially horizontal during play so that a bearing arrangement according to Figure 6 proves to be particularly advantageous. At im the bridge 51 shows essentially the horizontal position of the violin vertically upwards, so that here too gravity in a stiff direction of the Storage 3 acts. This shows that the acoustic vibration reduction system according to the invention due to its great flexibility in the different game positions of the individual instruments can be adjusted. If necessary, the Angular alignment of the compliant direction of movement by appropriate Alignment of the sound vibration absorption system or the contained therein Joints in relation to the sound body are chosen accordingly.

The sound vibration removal system according to the invention can be used for weight loss of sound vibrations on original acoustic instruments, or semi-acoustic Instruments that do not emit loud direct sound are used become. Because of the statically stable, but in the area of the sound-conducting Components of low-loss construction and because of the relative to the known Pickup systems with very high amplitudes on the transducers result significantly higher electrical output levels. The constructionally high useful sound vibration signal does when using regenerative converter types like the piezoelectric diaphragm transducer described, the preamplification of the electrical output signal and avoids the associated negative effects. Cost of preamplifier and necessary supply with Auxiliary energy is eliminated. The with the acoustic vibration system according to the invention equipped musical instruments can if necessary directly to the usual Line-in sockets connected to inexpensive recording devices and amplifiers become.

The high mass contributes significantly to the high electrical output signal passive movement pole of the converter and the effective decoupling of this Masses due to flexible joint bearings.

Due to the design with a tappet, there is the possibility of structure-borne noise both in large and in small areas or at sharp bumps as well as at convex or concave parts of the sound body to be able to lose weight. Due to the pressing spring, the reliability of the Contact point between the transducer and the sound vibration take-off point secured.

The inertial mass is relative to the vibration-decoupling bearings to the sound pick-up point stored in a global reference environment. The place of fortification these bearings can optionally be in the immediate vicinity of the sound collection point, but also selected at more distant parts of the sound body will take place or even in places that are not part of the sound instrument represent.

Claims (26)

Sound vibration acceptance system for converting sound vibrations of a sound instrument into electrical signals with at least one mechanical-electrical converter (14) with an active and a passive (6) movement pole, the active movement pole being able to be brought into contact with a vibrating element (8, 11) of the sound instrument either directly or via an intermediate pass-through element (7), at least one inertial mass element (2) which is connected to the passive movement pole (6) of the transducer (14), and at least one vibration-decoupling mounting (3) which is independent of a connection via the transducer (14) for mounting the at least one inertial mass element (2) and for vibration decoupling parallel to the direction of the sound vibrations to be picked up. Sound vibration absorption system according to Claim 1, in which the at least one inertial mass element (2) and the connection of the inertial mass element (2) to the passive movement pole (6) of the at least one transducer (14) have an elastic modulus of at least 20 N / mm ² . Sound vibration acceptance system according to one of claims 1 or 2, which the bearing stiffness per inertial mass element (2) in the direction parallel a value smaller than (TM / 4) (N / (g. Mm)) if the inertial mass parallel to the vibration decoupling Storage still has other bearings, or one Value less than (TM / 8) (N / (g · mm)) when the vibration-decoupling Storage essentially the only cause of static inertial mass storage forms, where TM is the mass of the inertial mass element (2) in grams. Sound vibration acceptance system according to one of claims 1 to 3, which the at least one inertial mass element (2) has a mass greater or equal to 20 g. Sound vibration acceptance system according to one of claims 1 to 4, which the vibration-decoupling bearing (3) is designed such that their bearing rigidity parallel to the direction (21) of the acoustic vibration to be reduced at most ½ x the bearing stiffness perpendicular to this direction is. Acoustic vibration pickup system according to claim 5, wherein the vibration decoupling Storage (3) an articulated guide with at least one Includes an articulated arm and a joint. Sound vibration pickup system according to claim 6, wherein the vibration decoupling Storage (3) a parallelogram with at least comprises two articulated arms (42) and four joints (41). Acoustic vibration collection system according to claim 7, wherein the parallelogram pages parallel to the direction (21) of the vibration to be picked up at least ½ times as long as the parallelogram pages (41) perpendicular to Direction of the vibration to be picked up. Sound vibration acceptance system according to one of claims 6 to 8, which the joints as solid-state joints, in particular rubber bearings or Bending joints (41) are executed. Acoustic vibration acceptance system according to claim 9, with bending joints (41) as solid-state joints, the bending points in the joints at most 0.1 times as thick as the length of the joints. Sound vibration acceptance system according to one of claims 1 to 10, with at least one pressing device (4) for the defined prestressing of the at least a transducer (14) towards a sound vibration take-off point (8, 81, 82) of the sound instrument. Sound vibration acceptance system according to claim 11 and one of the claims 6 to 10, in which the pressing device (4) comprises a spring which between a point of attack of the stationary part of the converter system and any power-transmitting reference environment is arranged. Sound vibration acceptance system according to one of claims 1 to 12, with a pass-through element in the form of a plunger (7) for forwarding the Sound vibration from the sound vibration take-off point (8, 81, 82) of the Sound instrument to the at least one transducer (14), the plunger (7) is arranged such that it is between the active pole of movement at least one transducer (14) and a sound vibration tapping point (8, 81, 82) of the sound instrument is arranged when the sound vibration control system with a sound vibration tapping point (8, 81, 82) is in contact. Acoustic vibration pickup system according to claim 13, wherein the plunger (7) a smaller expansion in the direction (21) of the acoustic vibration to be reduced than in a direction perpendicular to it, especially in the direction of the acoustic vibration to be reduced is less than 0.1 times as large as in Directions perpendicular to it. Sound vibration acceptance system according to one of claims 13 or 14, wherein the plunger (7) is designed separately and on the active movement pole of the transducer (14) on the one hand and a sound vibration take-off point (8, 81, 82) of a sound instrument on the other hand can be pressed. Sound vibration acceptance system according to one of claims 13 or 14, in which the plunger (7) is designed as part of the transducer (14) and loosely a sound vibration take-off point (8, 81, 82) of a sound instrument can be pressed. Sound vibration acceptance system according to one of claims 13 or 14, where the plunger is fixed to the sound vibration take-off point (8, 81, 82) a sound instrument connected and loosely pressed to the transducer (14) is. Sound vibration absorption system according to one of claims 15 to 17, which the loose connection point is designed to be angle-tolerant, in particular comprises a cylindrical, a spherical or a pointed element. Sound vibration acceptance system according to one of claims 1 to 18, which the at least one transducer is a piezoelectric element, in particular comprises a membrane (14) with a piezoelectric coating. Sound instrument with a sound vibration reduction system according to a of claims 1 to 19 and at least one sound vibration removal point (8, 81, 82), which vibrates when the sound instrument is in operation becomes. A sound instrument according to claim 20, wherein the at least one sound vibration tap includes a swing arm (11), one of which End has an oscillating surface which is in contact with the transducer (14), wherein the swing arm has an elongated shape. Sound instrument according to one of claims 20 or 21, wherein the sound instrument a musical instrument, especially a stringed instrument with a Web (5, 51). Sound instrument according to claims 21 and 22, wherein the at least a swing arm (11) is part of the web (5). A sound instrument according to any one of claims 20 to 23, wherein the sound instrument is a semi-acoustic instrument. Method for removing sound vibrations from a sound instrument and conversion to electrical signals with a sound vibration reduction system (30) according to one of claims 1 to 19. Method for removing sound vibrations from a sound instrument, in which the sound vibrations from at least one mechanical-electrical Transducers (14) are added and converted into electrical signals be converted, the active pole of movement of the at least one Transducer (14) either directly or via a pass-through element (7) with a Sound vibration tapping point (8, 81, 82) of a sound instrument in contact and the passive movement pole (6) with at least one inertial mass element (2) is connected in the direction (21) of the to be removed Sound vibration is vibration decoupled.

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