WO1990003025A1

WO1990003025A1 - Sound radiation device and musical instrument

Info

Publication number: WO1990003025A1
Application number: PCT/EP1989/001068
Authority: WO
Inventors: Albert Hattermann; Heinrich BÜCKER; Wolfgang Bachmann; Wilhelm Schaffrath
Original assignee: Wilhelm Schimmel Pianofortefabrik Gmbh
Priority date: 1988-09-14
Filing date: 1989-09-13
Publication date: 1990-03-22
Also published as: JPH04500735A; EP0434754A1

Abstract

A device for radiating sound by means of a plate-shaped, electrodynamically activated sound unit, characterized in that the plate-shaped sound unit is of an even or slightly curved design, in the manner of the single-layer or multilayer soundboard (11) of a musical instrument. A preferred soundboard (11) is that of a tuned piano. Said soundboard (11) constitutes the baffle of at least one electromagnetic loudspeaker. This ensures excellent sound quality when reproducing recorded piano music.

Description

Sound radiation device and musical instrument

The invention relates to a device for sound radiation by means of a plate-shaped, electro-dynamically excited sound body.

The inventive concept can be implemented in particular in connection with a key-operated musical instrument with a data processing device, with which the actuation of the keys is converted into electrical signals corresponding to sound values, and with a device for sound radiation, to which these signals are supplied.

In particular, a musical instrument comes into consideration, in particular a piano or grand piano, with strings that are stretched over bridges and are excited to vibrate, and with a plate-shaped sound body that is flat or flatly curved in the manner of a single-layer or multi-layer soundboard known for this Materials is formed.

Conversely, the invention also enables a device for the electro-dynamic conversion of mechanical vibrations of a plate-shaped sound body into electrical signals.

The reproduction of piano sounds by conventional loudspeaker systems has, due to physical reasons, some serious defects. The reproduction via two separate loudspeaker boxes gives a spatial impression, but it does is not comparable to that achieved by piano and ^'wing soundboards diffuse sound field. Every conventional loudspeaker system generates, due to its construction, non-linearities with regard to frequency and phase response as well as transient and decay behavior, which leads to a distortion of the sound. The greater the deflections of the membrane, the stronger this effect appears.

For example from GB 2 027 316 A and EP 0 054 945 AI loudspeaker systems for installation in motor vehicles or furniture are known, with which an improved reproduction of acoustic vibrations can take place, particularly in the low frequency range. It is based on the idea of using panels from vehicles or furniture as a vibrating and noise-producing medium.

From DE 15 37 581 B2 an electroacoustic transducer arrangement is known, which converts an electrical signal received from a Toπkopf or a similar source into the dynamic movement of a coil, which in turn is attached to the soundboard and gives it an oscillation.

However, these known devices cannot satisfy the reproduction of demanding piano sounds and are to be seen more in the solution of special problems, for example in the reproduction of music in acoustically rather unfavorable positions, for example in motor vehicles.

To improve the sound of piano music to be transmitted, DE 36 25 040 AI proposes to equip a piano housing with a cavity on the inside and to provide a microphone in this substantially completely. The cavity should be enclosed by the soundboard and part of the housing below the soundboard. A special structure made of plastic foam and other elements is used for improved shielding against disturbing external influences.

Here too, however, the problem remains that the reproduction via the loudspeaker boxes does not correspond to the desired diffuse sound field, but rather to an artificial acoustic field prevailing at a specific point on the piano.

In contrast, the object of the invention is to propose additional possibilities for sound reproduction while avoiding the disadvantages of the prior art.

This object is achieved in a device for sound radiation by means of a plate-shaped, electro-dynamically excited sound body in that the plate-shaped sound body is flat or slightly curved in the manner of a single-layer or multi-layer resonance floor of a musical instrument made of known materials and the Forms membrane of at least one electromagnetic loudspeaker, consisting of a pot-shaped permanent magnet and a voice coil, the voice coil engaging at least one loudspeaker via a drive plunger on the plate-shaped sound body.

Recorded music, especially piano music, is reproduced by this new device in first-class clan quality and dynamics. By using a soundboard made of materials that are otherwise used for pianos, a lifelike sound is achieved. Of course, it is also possible to deliberately falsify a lifelike sound through certain changes in the soundboard. The application is also not limited to piano music. If soundboards are made from materials otherwise used for violin cases, violin sounds can be reproduced particularly true to life. The same applies to guitars and other musical instruments with soundboards.

If the plate-shaped sound body is formed by the built-in soundboard of a piano or grand piano ready to play, completely new uses arise. A piece previously played and recorded on the same piano or grand piano can then be played directly on the piano. This enables completely new methods of piano teaching, since the pupil can be shown his own mistakes, particularly with regard to expression, emphasis, etc.

Even sophisticated, advanced pianists or composers can use this device, for example in connection with a musical instrument, for example as a self-check.

It will also be possible to accompany yourself on the piano and thus play four, six, eight or more hands of piano works with little effort. Artificial accompaniment, as was previously possible in electronic organs, is very sterile and cannot meet the demands in terms of sound quality. If, on the other hand, attempts have been made to accompany piano works recorded on tape with a conventional piano, the discrepancy fell in terms of sound quality, mood and dynamics. With the new devices, however, accompaniment without this discrepancy and with excellent piano quality is possible.

If desired, an electronic alienation of the played sound can of course also take place. Certain frequencies can be hidden, amplified, or rearranged. Artificial reverberation can be created or attenuated. Since the playback takes place via a soundboard, as is known from pianos, a sound that is perceived as "classic" is created.

A complete set of concertos can, of course, also be imported from a separate electronic unit, in accordance with a current fashionable trend, which is then accompanied by the piano (so-called "concert minus 1").

There is also a fundamental difference to the so-called self-playing pianos known since the turn of the century. Their principle is based on the fact that the sound effect is achieved by driving the mechanism (lever mechanism of the mechanism). For the control of this self-playing piano for moving the playing of pianos and grand pianos, punched tapes and other data carriers for the tone sequence and pieces of music are known.

In the present invention, however, the resonance floor and the entire resonance body are not excited with the participation of the musical mechanism. Rather, the soundboard acts as a vibrating membrane that receives impulses from the outside through a drive tappet. The very special character of the piano sounds in terms of its sound properties is generated digitally and in this form is fed into the original piano sound body via the vibration exciter. As a result, the sound body is excited in a vibratory spectrum and in a manner from the outside, as is otherwise the case with the original piano playing via the piano strings. This leads to a comparable vibration behavior, which the soundboard otherwise shows through the mechanical excitation via the sound strings, without these having to be excited via the mechanism.

This is mainly due to the fact that the resonance floor built into a piano with special tension ratios has special vibration characteristics, which are based on the construction of the sound body. If such a sound body is excited from the outside, it vibrates in the same way as if it were directly through the Sound strings excited. The original filter effect of the sound body and the soundboard, as a result of which the sound character of piano sounds is determined, is therefore retained.

The inventive concept can also be used in a key-operated musical instrument with a data processing device with which the actuation of the keys is converted into electrical signals corresponding to sound values, and with a device for sound radiation to which these signals are supplied.

Such musical instruments are also known as so-called digital pianos and have also been on the market in versions for domestic use since around 1987. You own Keyboards similar to traditional pianos or grand pianos. Sensors or other elements detect which key is pressed and use a data processing device to determine an electrical signal that corresponds to the associated sound values. Different mechanisms can also be used to determine the strength or speed with which the button is pressed; a value for the volume can be determined from this.

The electrical signal corresponding to the sound values is now fed to a device for sound radiation. These are usually loudspeakers that are either permanently installed in the musical instrument or can be connected externally, for example as parts of a radio system.

Since complex hammer mechanisms, strings and the like are no longer required, such digital pianos are very competitively priced compared to conventional pianos. In addition, they also offer the advantage that headphone connections can be provided, which make it practically sound-free for the environment. The presence of a data processing device can also be used to deliberately alienate the sound, for example unusual tempering instead of the "well-tempered" pianos that are common today.

Therefore, if all sorts of electronic gimmicks are possible with the digital pianos, their sound quality cannot satisfy the originally intended purpose, namely the simulation of a conventional piano. There is no authentic one Sound, but there is always the impression that synthetic music is in front of you. The reproduction of the electrical signals by conventional loudspeaker systems has, due to physical reasons, some serious shortcomings. The reproduction via two separate loudspeaker boxes gives a spatial impression, but it is not comparable to the diffuse sound field achieved by conventional pianos. Due to the design, non-linearities arise with regard to frequency and phase response as well as transient and decay behavior, which leads to distortion of the sound. The greater the deflections of the membrane, the stronger this effect appears.

In such tasteπbetätigteπ musical instrument having a Datenvεrarbeitungseiπrichtuπg better sound reproduction can be achieved in that ^• the device comprises for Schallabstrahluπg a plate-shaped electro-dyna ish excited sound that soundboard flat or slightly curved in the manner of a single- or multilayer of a Musik¬ instrument is made of known materials for this purpose and forms the membrane of at least one electromagnetic loudspeaker, consisting of a pot-shaped permanent magnet and a voice coil, the voice coil engaging at least one loudspeaker via a drive plunger on the plate-shaped sound body and the electromagnetic loudspeaker (s) the electrical signals corresponding to the sound values are supplied.

The piano music played by the pianist is transformed into a first-class, barely reproducible sound quality and dynamics to be distinguished from a conventional piano. By using a soundboard made of materials that are otherwise used for pianos, a lifelike sound is achieved.

This improvement in sound quality is possible without having to forego the advantages that a digital piano offers compared to a conventional piano: it is competitively priced, music playback via headphones, i.e. without sound emission to the outside, remains possible, on piano adjustments, strings. Spannuπgeπ and the like can be omitted.

It is also possible to record a piece played on the digital piano and then to play this recorded piece directly, without loss of quality. This enables completely new methods of piano lessons, in which digital piaπos could not be used due to their distorting sound. Now, however, it becomes possible to immediately demonstrate to the student his own mistakes, particularly with regard to expression, emphasis, etc.

Even demanding advanced pianists or composers can use this musical instrument, for example as a self-check.

Another field of application of the invention is a musical instrument, in particular piano or grand piano with strings that are stretched over bridges and are excited to vibrate, and with a plate-shaped sound body that is flat or slightly curved in accordance with Art a single or multi-layer soundboard is made of known materials.

These musical instruments with strings stretched over bridges, especially pianos or grand pianos, have enjoyed great popularity for centuries. However, their use is limited. In order to avoid the still incomplete music which is often perceived as disturbing by the surroundings during practice, one has hitherto relied on digital piaπos according to the above description which have headphone connections.

The sound of the digital pianos can already be significantly improved by the use of the key-operated musical instruments according to the invention with data processing devices, but many public circles will still reject these digital instruments To a certain extent, even objectively, these improved instruments are still referred to as digital pianos and may be viewed with reservations.

With the invention, however, a musical instrument, in particular a piano or a grand piano, with strings that are stretched over bridges and are excited to vibrate, can be proposed, which has a further usability compared to conventional pianos and is nevertheless not a digital piano .

This is achieved in that the webs are spaced apart and contact-free from the sound body (resonance floor), that sensors for Scanning of the bridge vibrations are provided, which emit digital signals to a control unit, that the control unit converts and processes signals into sound values and outputs the processed signals to a device for sound radiation, and that the device for sound radiation transmits the plate-shaped, electrodynamically excited sound body (Reso¬ nanzboden), which forms the membrane of at least one electromagnetic loudspeaker, consisting of a pot-shaped permanent magnet and a voice coil, the voice coil of at least one loudspeaker engaging the plate-shaped sound body via a drive plunger and the electromagnetic loudspeaker (s) corresponding to the sound values trical signals are supplied.

The piano music played by the pianist is reproduced by this novel musical instrument in a first-class sound quality and dynamism that can hardly be distinguished from a conventional piano. By using a soundboard made of materials that are otherwise used for pianos, a lifelike sound is achieved.

This improvement in sound quality in relation to digital pianos is achieved, although at the same time there is an improvement and expansion of the possibilities compared to conventional pianos.

If required, the sound emission to the outside can be significantly reduced. This means that the piano can be played loudly or quietly with the same key stroke. For this purpose, only the signals output by the sensors to the control unit are processed in this way. processes that their forwarding to the device for

Sound radiation occurs with the proviso that the vibrations have a reduced amplitude.

Basically, music can be played using headphones, i.e. without any external sound.

The key actuations are provided with all conventional or theoretically desired hammer mechanisms, and the piano also has all the other elements, including the strings, that are desired even by the most demanding pianist.

The electro-dynamic used for electro-dynamic excitation or external Schwinguπgserreguπg

Systems functionally preferably consist of a magnet system, a voice coil, a centering, a holder and a coupling. The loudspeaker magnet system has a cup-shaped structure with an annular air gap. The voice coil protruding into the air gap of the magnet system preferably consists of a single-layer or multi-layer copper winding which is applied to a tubular coil carrier consisting of an unmagnetic substance. However, it can also be designed to be self-supporting by casting or gluing.

The centering serves for the distortion-free transmission of the vibrations. It is preferably carried out via a double diaphragm which is attached to the stationary part of the loudspeaker on the one hand and to the drive tappet on the other hand, the drive tappet being mounted centrally in a recess in this double diaphragm. The double membrane holds the coil in the necessary coaxial position in the annular gap around the Vibration coil so firm that small axial vibrational movements are very easily possible, while radial parallel displacement or tilting of the coil axis is opposed to the greatest possible resistance.

The stationary part of the magnet system or loudspeaker is carried by a holder made of metal, wood, plastic or composite material. This holder can be connected to the stationary frame, also called the catch. It should be noted that it is preferably shielded from feedback from vibrations of the soundboard to the loudspeaker. The holder can contain adjusting devices with which the position of the magnet can be adjusted in all spatial axes and planes.

The connection between the voice coil and the resonance base is preferably made via a coupling head. It has a flange which is flat on the resonance floor and firmly connected to it. On the side facing away from the soundboard, it has a sleeve into which the drive tappet can be inserted. The drive tappet is preferably fastened in the sleeve by gluing or screwing. Welded or soldered connections or the combination of different connection types are also conceivable.

Alternatively, the voice coil can also be arranged directly on the drive plunger, for example via an adhesive connection. In this case, the drive plunger additionally takes on the role of the coil carrier. On his facing the soundboard In this case, the end can be closed with a stopper. This stopper is preferably attached directly to the soundboard, for example screwed on. The advantage of this embodiment consists in the smaller number of components required, since the drive tappet and the coil carrier are formed by one element. At the same time, a more direct transmission of the vibrations to the soundboard is guaranteed.

The assembly is made easier if the magnet has a centering hole for a centering pin. As a result, an alignment of the parts connected to the drive tappet, which subsequently vibrate with the soundboard, is achieved, in particular the position of the voice coil. The magnet and the further stationary parts can then be pushed onto the already arranged parts by means of the centering pin and thus aligned.

For the stability and sound properties of the soundboard as well as for some forms of vibration transmission, it is expedient in the embodiment with the webs spaced apart from the soundboard if spars are also provided on the soundboard which are spaced apart but parallel to the webs over which the strings are stretched. These bars no longer come into contact with the strings themselves; however, they run approximately where the sound bars also run in conventional pianos.

An embodiment for the external vibration excitation of the soundboard and sound body consists in the fact that a first mechanical vibration coil uses a tappet to trigger those tilting vibrations on the sound. bridge that would otherwise be given by the sound strings to the sound bridge. A second oscillation coil transmits the horizontal oscillation parts to the soundboard, which otherwise are transmitted to the soundboard via the sound bridge.

A particularly high sound quality can be achieved by a construction of three electromagnetic loudspeakers. A first loudspeaker, which is arranged away from ribs and webs, is used to transmit the vertical vibration to the soundboard. A second loudspeaker engaging on a bridge transmits horizontal tilting vibrations to the bridge. Above all, harmonics are transmitted as a result. A third loudspeaker works with a rocker bearing via a lever system and, due to the higher inertia of such a construction, transmits vibrations with a lower frequency directly to the soundboard, which is primarily the low frequency range.

When used in accordance with the invention in a digital piano without strings, a further improvement in the sound quality can be achieved in that sound bars provided on the plate-shaped sound body are provided with a tensioning device for simulating the strings.

The strings otherwise provided in ready-to-play pianos, in addition to transmitting vibrations to the resonance body, in turn also influence the vibrational behavior of the resonance body.

By transferring suitable prestresses to the sound bars, the sound behavior can also be approximated with regard to these corrections. It would also be possible, but more expensive and less preferable for a digital piano, to provide a complete string covering of the soundboard.

In the improvement of a piano according to the invention with bridges spaced apart from the sound body, a further improvement in the sound quality can be achieved in that the bridges over which the strings are stretched are provided with a tensioning device which pretension them in the position that they are in conventional pianos take in. It should be taken into account that the webs generally do not run in a straight line, but in acoustically induced curves. A special sound fidelity is achieved by the bias.

In addition to a device for sound radiation, the invention also proposes a device for the electro-dynamic conversion of mechanical vibrations of a plate-shaped sound body into electrical signals. This microphone-like device is also characterized in that the plate-shaped sound body is flat or slightly curved in the manner of a single-layer or multi-layer soundboard of a musical instrument made of materials used for this purpose and forms the membrane of at least one electro-magnetic microphone.

If necessary, the vibration pickup can also be the vibration generator at the same time. It is then no longer necessary to record the music played on the piano with a separate microphone, rather the soundboard of the piano is used directly as a microphone membrane. The vibration characteristics of Klaπgsteg and

Soundboards are therefore recorded exactly in the form in which they are fed.

The invention is described in detail below with reference to the figures.

Show it:

FIG. 1 a shows a sectional principle illustration through a section of a device according to the invention, FIG. 1 b shows a sectional principle illustration similarly

FIG. 1 a through a section from one musical instrument according to the invention in another

2 shows a section through a special embodiment of a loudspeaker, FIG. 3 shows a section through another special embodiment of a loudspeaker,

4 shows a detail from FIG. 3,

5 shows a section through a further embodiment, FIG. 6 views of a soundboard from above, below and from the side, and FIG. 7 shows a section through a device according to the invention

Musical instrument.

A musical instrument, in particular a grand piano or a piano, has a plate-shaped, flat or slightly arched soundboard 11, of which in

Fig. 1 shows a detail and in Fig. 6 a schematic overall view is shown. The soundboard 11 carries ribs 12. On the side of the soundboard 11 facing away from the ribs 12, as shown in FIG. 1a, a sounding web 13 or, as shown in FIG. a spar 13c may be arranged, the sound bridge 13 or spar 13c running parallel to the soundboard 11, but perpendicular to the ribs 12.

In Fig. 1 the sound strings 14 are supported on the sound bridge 13.

In FIG. 1b the sound bridge 13, on which the piano strings 14 are supported, runs spaced from the spar 13c. The sound bridge 13 (possibly a plurality of sound bridge 13, 13b) in this case run at a uniform distance from the soundboard 11. The spar 13c is provided parallel to them.

On the sound bridge 13 there is (not shown) a number of sensors for scanning the bridge vibrations, which emit digital signals to a control unit. The control unit converts the signals into sound values and processes them and delivers them to a device for sound radiation.

The device for sound radiation has the soundboard 11 as an essential component. The resonance floor 11 is the membrane of at least one electromagnetic loudspeaker. The loudspeaker has a permanent magnet and a voice coil as well as a drive plunger which engages on the soundboard 11.

A drive 20 or 30 (in FIG. 1) is provided in each case for transmitting the horizontal or the vertical components of the signals which result from the web vibrations of the blade web 13. The drive 20 has a drive plunger 21 which is fastened at one end to the spar 13c, while its other end is connected via a joint to the vibrating coil 22 arranged on a tubular coil carrier 23. The voice coil 22 with the tubular coil carrier 23 are mounted in a pot-shaped permanent magnet 24.

If current flows through the voice coil 22, the tubular coil carrier 23 moves in the magnetic field of the permanent magnet 24 and thus also sets the drive plunger 21 in vibration, which in turn transmits it to the spar 13c.

The drive 30 for the transmission of the vertical components of the web vibrations also has a drive tappet 31 which is arranged on the one side in the spar 13c and on the other side is connected via a joint to a tubular coil support 33 on which a vibration coil 32 is attached is. This voice coil 32 is in turn movably mounted in a permanent magnet 34. The mode of operation corresponds to that of the drive 20.

The difference between the two drives is that the tubular coil carrier 33 transmits its vibrations axially to a drive tappet 31, which in turn transmits these vibrations as a vertical component to the spar 13c.

On the other hand, the tubular bobbin is offset

23 the drive plunger 21 in transverse swings, which it passes on as a horizontal component to the spar 13c. 2 shows a special embodiment of a device according to the invention. Here too, the sound of an excitation system is to be transmitted to a sound body, namely a soundboard 11. The drive system includes a drive tappet 41, which is moved by the movement of a voice coil 42 with a tubular coil support 43 in a magnet 44. The magnet 44 includes a pole core 45. The magnet 44 is also enclosed by a lower pole plate 47 and an upper pole plate 48, the upper pole plate 48 having a central opening in which the tubular coil carrier 43 with the vibrating coil 42 is arranged axially.

The drive plunger 41 is fastened to a coupling head 46, which in turn is fastened to the tubular coil carrier 43.

The transmission of the vibration from the drive tappet 41 to the soundboard 11 does not take place directly, but via a lever system. For this purpose, a rocker bearing 51 is located between the soundboard 11 and a lever arm 52, which is arranged essentially parallel to the soundboard. The lever arm 52 is coupled at one end to the drive tappet 41, at the other end it is mounted on the soundboard 11 with a fastening 53. The rocker bearing 51 is arranged between the two elements 41 and 53.

A hard adhesive is proposed for connecting the coupling head 46 to the tubular coil carrier 43, and one or more centering membranes can also be used to guide the vibrating coil.

This lever or rocker-like construction serves especially for the transmission of deep tones. Due to the inertia of the lever system (this can also be reinforced by a suitable elastic material for the rocker bearing 51), only those movements of the drive tappet are transmitted which last for a certain period of time. But this is only the case for low-frequency vibrations. By appropriately designing the lever, the preferred frequency range of the tones can also be selected. Through the use of several such lever or rocker systems with different specifications at different points on the soundboard, a true-to-life transmission in the low-frequency range can take place in this way.

3 and 4, a construction is shown, which is used primarily for the transmission of tones in the medium frequency range. It transmits all vibrations directly from the magnetic system to the soundboard.

A drive tappet engages on the soundboard 11

31 at. The drive plunger 31 is with a voice coil

32 connected on a tubular bobbin

33 is mounted in a magnet 44. A magnet core 45 belongs to the magnet 44 (as in FIG. 2). The magnet 44 is also enclosed by a lower pole plate 47 and an upper pole plate 48, the upper pole plate 48 having a central opening in which the tubular coil carrier 33 axially is arranged with the voice coil 32.

A double membrane is used for centering. The upper centering membrane 61 is fastened to a coaxial spacer ring 62. This coaxial spacing ring 62 is in turn attached to the upper pole plate 48. The outer edge of the upper centering membrane 61 is thus stationary. It is ring-shaped and therefore has an inner circular recess. Through this recess, the tubular coil carrier 33 extends with the vibrating coil 32. The upper one

Centering membrane 61 is fastened to the tubular coil carrier 33. As can be seen in particular from FIG. 4, this fastening can be effected, for example, by latching into an annular groove 63.

In a similar manner, a lower centering membrane 66 is received in the ring gap between the magnet 44 and the Polkerπ 45. It is on the one hand with its outer annular edge on the magnet 44 and on the other hand with its inner, also circular -

The edge of the upper centering membrane 61 is thus stationary. It is ring-shaped and therefore has an inner circular recess. The tubular coil carrier 33 with the vibrating coil 32 extends through this recess. The upper centering membrane 61 is fastened to the tubular coil carrier 33. As can be seen in particular from FIG. 4, this fastening can be effected, for example, by snapping into an annular groove 63.

In a similar manner, a lower centering diaphragm 66 is received in the ring gap between the magnet 44 and the pole core 45. It is attached on the one hand with its outer annular edge to the magnet 44 and on the other hand with its inner, also circular edge at the lower end of the tubular coil support 33.

The double membrane with the upper centering membrane 61 and the lower centering membrane 66 is to some extent Frame flexible. While it allows axial movement of the tubular coil former 33 of the vibrating coil 32 around the pole core 45 (the amplitude of which is relatively small), it prevents radial or tilting movements of the tubular coil former 33

Movements would have a component in the membrane level and are therefore filtered out.

The upper circular end of the tubular coil carrier 33 is closed off by a coupling head 46. This is firmly connected to the tubular coil carrier 33 by a hard adhesive 71. The drive plunger 31 is seated on the coupling head 46. It can be screwed (see FIG. 4), for example, into the coupling head 46.

The drive tappet 31 projects into a sleeve 72. The sleeve

72 is made in one piece with a flange 73. This flange is flat and parallel to the soundboard 11 and is fixedly mounted on the soundboard 11, for example by means of screws through bores 74. The sleeve 72 on the flange 73 is opened vertically downward, so that the drive plunger 31 projects precisely into it. An adhesive space 75 is formed between the drive tappet 31 and the inner wall of the sleeve 72. Venting or filling bores 76 extend through the wall of the sleeve 72. An adhesive can be introduced into the adhesive space 75 through these openings 76, which creates a firm connection of the drive tappet 31 with the sleeve 72 and thus with the flange

73 and the soundboard 11 leads. This connection must be firm in order to be able to transmit the vibrations of the tubular coil carrier 33 securely to the soundboard 11 without any distortions occurring. Axially around the drive plunger 31 is below the sleeve 72 a sealing ring 77 formed (shown in Fig. 4 somewhat spaced from the sleeve 72). This seals the adhesive space 75 ^" downwards and prevents the adhesive from escaping during the adhesive bonding.

5 shows a construction which, like the conception of FIGS. 3 and 4, directly transmits the vibrations from the magnet system to the soundboard 11.

A drive tappet 81, however, also takes over the function of the coil carrier. The vibration coil 82 is fastened on it. The tubular drive plunger 81 is mounted in a magnet 44, as was the case with the tubular coil carrier in the previous embodiment.

Abgewandteπ on by the magnet 44 and the re sonanzboden 11 facing side ^'of the drive ram 81, a plug 87 is provided which includes ab¬ the pipe end. Between the plug 87 and the drive plunger 81, an adhesive space 75 is filled with adhesive and ensures a firm and secure connection. The plug 87 is flat on the side facing the soundboard 11 and is circular in accordance with the tube. To secure the adhesive connection and to enlarge the adhesive space 75, the plug 87 pulls a little sleeve-like into it from the end of the drive plunger 81. The stopper

87 is screwed to the soundboard 11 with wood screws 88.

The magnet 44 has a central one vertically to the resonance base 11, that is to say axially to the vibrating coil 82 and to the drive plunger 81, the S pu leπträ ger, aligned center ¬ trier bore 89.

The assembly of a loudspeaker or a drive unit according to this construction proceeds as follows: First, the plug 87 (preferably made of aluminum) is mounted on the soundboard 11 at the intended location using wood screws 88. The drive plunger 81 with the voice coil 82 is pushed onto it and firmly glued to the plug 87 in the region of the adhesive space 75.

A centering pin can now (or even before the plug 87 is placed on the soundboard 11) inserted into a hole (not shown) centrally in the plug 87. It is preferably screwed into a thread provided in this bore so that it is exactly perpendicular to the bottom surface of the plug 87 and thus the soundboard 11.

The magnet 44 with its centering bore 89 is then pushed onto the centering pin. The centering pin passes through the centering bore 89 with a precise fit. At the same time, it is thus precisely aligned with the voice coil 82. The magnet 44 is then firmly connected to stationary parts, for example the frame or the catch. For this purpose, several adjustment screws are used, which are first tightened evenly on the frame. Then there may be a fine tuning. Finally, the centering pin is unscrewed and pulled out through the centering bore 89. When pulling out the centering pin, the magnet 44 remains in the adjusted position due to its attachment. The adjusting screws set the position in several

Terms firmly. A cup-shaped holder extends on the one hand a plurality of tension screws (approximately four) which are screwed into the thread in the magnet 44 and thus connect the holder and the magnet (pull together). The bracket is attached to a fixed part.

Radially through the cylindrical part of the pot-shaped holder which surrounds the magnet 44, several (also about four) pressure screws extend evenly over the circumference and are supported on the magnet 44. They are used for the X-Y orientation of the magnet. Further (approximately four) pressure screws extend parallel to the centering pin through the cover of the holder and are also supported on the magnet 44. They are used for Z orientation, although they also influence the X-Y orientation.

An oscillation of the voice coil 82 relative to the magnet 44 now leads to oscillatory movements of the resonance floor 11.

If the wood warps, problem-free readjustment is possible. The system is e.g. easily removable and re-attachable for transports. It is just as easy to replace defective voice coils 82 or those that have been destroyed by overload.

A combination of the embodiments from FIGS.

1 to 5 with one another and also with further loudspeaker devices is possible.

6 shows a soundboard 11 with a combination of such loudspeaker devices. The in Top view of a rectangular soundboard has diagonal, parallel ribs 12. A slightly curved, but essentially perpendicular to the ribs 12, a sound bridge 13 is arranged. Usually, pianos and grand pianos have a second bridge 13b. The first longer sound bridge 13, which extends approximately diagonally across the entire soundboard 11, is also referred to as a disc bridge or main bridge, the second shorter, approximately parallel to the first sound bridge 13b, on the other hand, as a bass bridge _, corresponding to the respective sound bridge 13. 13b supported sound strings, which are not shown in Fig. 6. The soundboard 11 is surrounded on the outside by a frame 15.

When used in a musical instrument with webs 13, 13b, which are arranged at a distance from the soundboard 11, the webs and spars would run as seen in the attached FIG. 6 in plan view. In the sectional view, the reference numerals 13 and 13b would have to be replaced by the reference numerals 13c and 13d for the bars, while in this case the sound bars 13 and 13b would be arranged exactly to the right of these bars in the drawing. The strings 14 would then run to the right of these webs 13.

In this embodiment, three devices for vibration transmission are provided on the soundboard 11. A drive 30 for transmitting the vertical component of the vibrations is arranged adjacent to one end of a sounding web 13, but at a distance from it and also at a distance from the ribs 12. This drive 30 corresponds, for example, to the embodiment shown in FIGS. 3, 4 or 5. Acting directly on the Klaπgsteg 13 and arranged near its opposite end the drive 20 for transmitting the horizontal component of the web vibrations. The principle of such a drive is shown for example in Fig. 1. This drive essentially transmits tones in the disc area.

By contrast, the third drive 40, which is arranged between the two ridges 13 and 13b, is also used at a distance from the ribs 12 for transmission in the low-frequency range. This drive is designed in accordance with the embodiment shown in FIG.

As an example of use in a musical instrument, the case similar to a digital piano is shown in section in FIG. 7. In a housing 1, as in known pianos and digital pianos, a keyboard 2 is provided, consisting of a series of keys, only one of which is shown in section. The keyboard 2 can be covered with a flap 3. The keys of the keyboard 2 can be pivoted about a pivot point ^'when ausgeleπkt from its rest position. They are biased into their rest position, to which they therefore automatically return.

The keystroke of the keys is registered and its duration and the hardness or speed of the keystroke are converted into a digital signal. This is done in a mechanical box 4, which is indicated in FIG. 7 only as a functional box.

Different modes of operation of the mechanical box 4 and the measuring sensors connected to it are conceivable. The speed of the keystroke can be determined, for example, by measuring which one The time interval between passing two predetermined points on the key stroke passes.

The digital signals of the mechanical box 4 are transmitted to an electronic box 5, which assigns these values to certain sound values. These sound values serve to control electromagnetic loudspeakers which are arranged on the soundboard 11.

As with conventional pianos, this soundboard 11 is set up as a vertical plate in the rear part of the housing 1 of the piano.

As with conventional pianos, it can be strung with strings, this has been assumed in the representation in the other figures. However, it is also possible to dispense with these strings and instead to simulate their sound influence by means of a tensioning device acting on the sound bars.

The keystrokes of the keys on the keyboard 2 are thus translated in the mechanical box 4 into digital signals, which the electronic box 5 uses to control drives 20 and 30, respectively.

While three drives of various types in different positions of the soundboard 11 are assumed in FIG. 6, in practice a number between four and about ten drives or loudspeakers has proven to be particularly favorable, taking into account the Cost-benefit idea. With this number of drives, excellent quality can already be achieved without the costs becoming too high. Increasing the number beyond ten brings only minor improvements.

Claims

Device for sound emission by means of a plate-shaped electro-dynamically excited sound body, which is flat or slightly curved in the manner of a single- or multi-layer soundboard (11) of a musical instrument made of known materials and the membrane of at least one electromagnetic loudspeaker, consisting of a pot-shaped Permanent magnet (24,34,44) and a voice coil (22,32,42,82) forms, the voice coil engaging at least one loudspeaker via a drive plunger (21,31,41,81) on the plate-shaped body.

Key-operated musical instrument with a data processing device, with which the actuation of the keys is converted into electrical signals corresponding to sound values, and with a device for sound radiation, characterized in that the device for sound radiation uses a plate-shaped electronic device. has dynamically excited sounding body, which is flat or slightly curved in the manner of a single-layer or multi-layer soundboard made of known materials and forms the membrane of at least one electromagnetic loudspeaker, consisting of a pot-shaped permanent magnet and a voice coil, the voice coil at least of a loudspeaker engages the plate-shaped sound body via a drive plunger and the electrical signals corresponding to the sound values are supplied to the electromagnetic loudspeaker (s).

Musical instrument, in particular piano or grand piano, with strings, which are tensioned by means of webs and are excited to vibrate, and a plat¬ tenförmigen ^'sound that one flat or slightly curved in the manner of one or multi-layer sound board is made of this known materials, characterized in that the webs (13, 13b) are spaced apart and contact-free from the sound body (soundboard 11), that sensors are provided on the webs for scanning the web vibrations, which emit digital signals to a control unit, that the control unit signals in Converts and processes sound values and outputs the processed signals to a device for sound radiation, and that the device for sound radiation has the plate-shaped, electro-dynamically excited sound body (soundboard 11), which has the membrane of at least one electromagnetic loudspeaker consisting of a pot-shaped permanent magnet ( 24,34,44) u nd forms a voice coil (22, 32, 42, 82), the voice coil of at least one loudspeaker via a drive plunger (21, 31, 41, 81) engaging the plate-shaped sound body and the electromagnetic loudspeaker (s) electrical signals corresponding to the sound values are supplied.

4. Device for the electro-dynamic conversion of mechanical vibrations of a plate-shaped sound body into electrical signals, the plate-shaped sound body being flat or slightly curved in the manner of a single-layer or multi-layer soundboard (11) of a musical instrument made of known materials and the membrane little ¬ at least one electromagnetic microphone, consisting of a pot-shaped permanent magnet (24,34) and a voice coil (22,32), the voice coil engaging at least one microphone via a drive tappet (21,31) on the plate-shaped sound body.

5. Device or musical instrument according to one of the preceding claims, characterized in that the plate-shaped sound body is formed by the built-in soundboard (11) of a ready-to-play piano or grand piano.

6. Musical instrument according to claim 3 and 5, characterized in that a tensioning device is provided which holds the webs in a shape which corresponds to the arrangement in ready-to-play pianos or grand pianos.

7. Device or musical instrument according to one of the preceding claims, characterized in that the drive plunger (31, 41, 81) of at least one loudspeaker or microphone runs with its longitudinal axis normal to the plate-shaped sound body (soundboard 11).

8. Device or musical instrument according to one of the preceding claims, characterized in that the plate-shaped sound body (soundboard 11) is equipped with a reinforcing frame extending along the entire edge of the plate.

9. Device or musical instrument according to one of the preceding claims, characterized in that the plate-shaped sound body (soundboard 11) is held in a fixed edge clamping.

10. Device or musical instrument according to one of the preceding claims, characterized in that with the soundboard (11) a plurality of electro-dynamic speakers or microphones are connected, of which one or one with its voice coil (32) via one with The drive plunger (31) of its longitudinal axis, which runs normal to the soundboard (11), and another or another engages with its voice coil (42) at one end of a double-armed lever (52, 53) which is parallel to the soundboard (11 ) runs and is supported on the resonance floor (11) in the manner of a rocker by means of an abutment (rocker bearing 51) which can be displaced in the longitudinal direction of the lever and is firmly connected to the sound board at its other end via an anchoring part (fastening 53).

11. The device or musical instrument according to claim 10, characterized in that the double-armed lever (52,53) made of an elastically resilient material, such as aluminum or glass fiber reinforced plastic, and the abutment (rocker bearing 51) made of a material of greater hardness, such as steel or Ceramic exists, and that the double-armed lever (52, 53) is held against the abutment with pretension and the abutment is designed as a tilting roller.

12. Device or musical instrument according to one of claims 10 or 11, characterized in that the loudspeaker (drive 30) or the microphone with the normal (vertical) on the soundboard (11) engaging plunger (21,31,81) in the treble area and the loudspeaker (drive 40) or the microphone, which acts on the soundboard (11) via the double-armed lever (52, 53), or the microphone are arranged in the low-frequency range.

13. Device or musical instrument according to one of claims 10 to 12, characterized in that a further loudspeaker (drive 20) or microphone is provided for detecting the tilting vibrations of the soundboard (11), its in the direction of the longitudinal axis of the voice coil (22) The extending coil carrier (23) runs in one plane parallel to the resonance floor (11) and is held at the upper end of a drive tappet (21) which rises from a spar (13c) or ridge web (13) and is anchored therein.

14. Device or musical instrument according to one of the preceding claims, characterized in that the drive tappet (31, 41) at least one loudspeaker or microphone at its end facing the pot-shaped permanent magnet (34, 44) with an end with the diameter of the voice coil ( 32, 42) matched solid ring body (coupling head 46) made of solid unmagnetic material, such as aluminum, copper or ceramic, on which a tubular coil support (33, 43) protruding into the annular gap of the pot magnet with the winding thereon arranged thereon Voice coil (32,42) is held.

15. The device or musical instrument according to claim 14, characterized in that the tubular coil support (33, 43) with the solid on the drive tappet (31, 41) attached to the ring body (Kopp¬ luπgskopf 46) is held by an adhesive connection.

16. The device or musical instrument according to one of the preceding claims, characterized in that that the drive plunger (81) of at least one loudspeaker or microphone is also the coil carrier for the oscillating coil (82) assigned to it.

17. The device or musical instrument according to claim

16, characterized in that the drive tappet (81) is tubular and is closed at its end facing the resonance floor (11) with a stopper (87) which in turn is fastened to the resonance floor (11).

18. Device or musical instrument according to one of the preceding claims, characterized in that the magnet (44) of at least one loudspeaker or microphone is provided with a centering hole (89) for a centering pin.

19. Device or musical instrument according to one of the preceding claims, characterized in that the speaker or speakers. the microphone or microphones are connected to electrical amplifiers, which in turn are connected to high recording and playback devices.

20. Device or musical instrument according to one of the preceding claims, characterized in that provided on the plate-shaped sound body Klaπgstege (13, 13b) are provided with a tensioning device for simulating the strings.

21. Device or musical instrument according to one of the preceding claims, characterized in that on the soundboard (11) adjacent to the webs (13, 13b), spars (13c) are provided which are arranged at a distance from the webs (13, 13b) .

22. Device or musical instrument according to one of the preceding claims, characterized in that the control unit is connected to recording and / or playback devices.

23. Device or musical instrument according to one of the preceding claims, characterized in that a total of between four and ten speakers are arranged on the soundboard.