EP0025118A1 - Arrangement for the acoustic reproduction of signals, presented by means of a right and a left stereo-channel - Google Patents

Abstract

Several single loudspeakers (1-9), which are preferably set up along a straight line, are used for generating two mutually inclined wave fronts which permit a stereo localisation over a large space. In this arrangement, both the left-hand and the right-hand stereo signal are applied via in each case individual delay elements (37-45, 46-54) to the single loudspeakers (1-9). In an advantageous embodiment, undelayed left and right stereo signals are applied to low-range speakers (74, 75), respectively, whilst delayed signals are only applied to the high- and mid-range speakers (1-9). <IMAGE>

Description

The invention relates to an arrangement for acoustic reproduction of signals which can be represented by means of a right and a left stereo channel, this arrangement containing a plurality of individual speakers, at least some of which are connected to the right and left stereo channels via delay devices.

There has long been a need in acoustic reproduction technology to reproduce the recorded sound events as realistically as possible. This need cannot be satisfied with just one channel or loudspeaker because it does not convey a spatial sound impression. So-called stereophony has therefore been proposed, in which two or more channels, ie transmission paths, are used. Two-channel stereophony has become established for radio, record and tape playback, while up to five channels are used in sound film. A disadvantage of the two-channel stereo is that the listener must be on the line of symmetry of the loudspeaker ^arrangement , that is, in the middle between the two loudspeakers or in their vicinity in order to obtain a spatial sound impression. On the other hand, the listener is to the right or left of the center of the two Speakers, a perfect stereophonic impression is only created when the distance between the listener and the loudspeakers is very large.

The well-known stereo transmission with two loudspeakers enables "directional listening" only in a very narrow area around the center plane of the stereo base. If both loudspeakers receive the same signal at the same level, only the listener who is within this narrow range locates the virtual sound source exactly in the direction perpendicular to the base. However, if the listening position is outside of this range, the listener hears the virtual sound source from a direction that is turned towards the closer speaker. This is based on two mutually supportive causes. On the one hand, the sound level that comes from the closer speaker is higher than that from the more distant speaker, and on the other hand, the wavefront of the closer speaker reaches the listener first. As a result, the listener, as described by the law of the first wavefront, increasingly localizes in the direction of the loudspeaker mentioned.

Since a loudspeaker arrangement that enables stereophonic hearing only in a narrow zone of the room is unsatisfactory in practice, considerable efforts have already been made to enable stereophonic hearing in a large area in front of the speakers. Such efforts include a. described in DE-AS 1 081 051. In these previously known experiments, separate loudspeaker systems or loudspeaker groups are provided for each channel in order to increase the stereo effect by means of a suitable directivity or reflection on side walls which are already present or have been constructed especially for this purpose. Although these measures have made it possible to widen the range in which stereophonic hearing is possible, such a system is not yet fully satisfactory. In addition, a great deal of structural effort is required, and such systems are also only inadequately adaptable to different application requirements, for example with regard to different expansion of the stereo base.

Various solutions have been proposed to overcome this disadvantage. One of these proposals relates to a transverse wave loudspeaker with a radiator plate (DE-PS .11 32 593, DE-PS 21 12 516; _R. Riedlinger: Structure and properties of a transverse wave loudspeaker, diss. Karlsruhe 1973). However, such transverse wave loudspeakers are extremely voluminous and moreover have poor reproduction of high frequencies. In addition, their directional characteristics are frequency-dependent. Finally, the directional characteristic of the radiator plate is also fixed, so that it cannot be adapted to the requirements of different lengths of the stereo base.

To avoid frequency-dependent directional characteristics, it has also already been proposed to use a plurality of line oscillators arranged in parallel, each transmitting only a specific frequency range (DE-OS 22 60 741). This makes the construction of a sound-emitting system very complex.

A loudspeaker arrangement with directivity is also known which has a multiplicity of individual loudspeakers ^p which are connected to phase-rotating elements, so that the direction of the main radiation can be inclined with respect to the direction perpendicular to the radiating surface (DE-PS 844 169). If this arrangement is used for the reproduction of two-channel stereo broadcasts, two loudspeaker chains must be provided. This also applies to other known loudspeaker arrangements which work with several loudspeakers and delay lines (DE-AS 10 81 051, 'column 4, line 34 ff).

Another arrangement (Walker, Wide range electrostatic loudspeakers, Wireless World, May 1955, pages 208ff and June 1955, page 265; Bürk: Ober electrostatic loudspeakers for larger frequency ranges, Funkschau, 1957, Issue 23, pages 633-636) is merely suitable for use with electrostatic speakers. In order to obtain two wavefronts that run at an angle to one another, a capacitor loudspeaker divided in the longitudinal stripe must be used an entire wall surface can be provided, the strips of which are designed as chain conductors. This is an effort that is usually not acceptable for average living spaces.

Finally, a sound reproduction system is also known which has a plurality of individual speakers which are connected to the two stereo channels via delay devices (US Pat. No. 4,105,864). The stereo channels are first placed on a mixer and then individually delayed as a uniform signal for certain speakers. With the exception of two main loudspeakers, the loudspeakers are supplied with mono signals which are delayed differently but are otherwise the same. Sloping wave fronts cannot form.

The invention has for its object to provide an arrangement for the acoustic reproduction of two-channel stereo signals, with which the stereo effect can be clearly perceived at different locations in a listening room and which can be set up with discrete individual speakers.

This object is achieved in that the left stereo signal is fed to a single speaker with a first delay assigned to this speaker and that the right stereo signal is fed to a single speaker with a second delay assigned to this speaker, the delays of the right and left stereo signals being so dimensioned are that the waves emitted by the individual speakers form two wave fronts.

Further refinements of the invention result from the sub! claims ..

auftreten durch die Erfindung

nicht erzeugt, so daß die Schallwiedergabe außerordentlich naturgetreu ist.The advantage achieved with the invention is, in particular, that very good localization of the sound is possible from any location, ie also outside the stereo center. Hall signals or the like, in contrast to the subject of US Pat. No. 4,105,864, where delay times of τ »

occur through the invention

not generated, so that the sound reproduction is extremely lifelike.

The invention goes u. a. from the consideration that the unsatisfactory results in previous efforts to improve stereophonic reproduction of sound signals are essentially due to the fact that the known systems do not allow a free, independent selection of the parameters delay (track wave speed), level curve and frequency response. The dimensioning of the previously known systems leads to a strong dependency of these parameters on one another. In addition, the use of radiator plates is limited, for example, by the fact that dispersion can be observed at very low frequencies due to the occurrence of bending waves, which leads to a frequency-dependent direction of the radiation.

In contrast, the playback system according to the invention is free from these disadvantages. It has no unwanted dispersion. The beam angle can be kept constant as required. The amplitudes of the signals in the direction of propagation can drop as required, or can be set to increase. Frequency-dependent changes in the amplitude of the signals can be avoided or adjusted according to requirements, for example to compensate for the bundling of loudspeaker groups, which becomes sharper with increasing frequency.

• 1 ms-3 dB; 3 ms-6 dB; 6 ms-9 dB; 10 ms-10 dB.

It is characteristic of the system according to the invention that the suitable selection of the system parameters, such as the number and distribution of the loudspeakers, delay and / or level setting of the individual loudspeaker signals, sets an overall directivity for the left and for the right stereo channel, which is determined by the choice of the listening position Runtime difference of the left, right signal inserts opposes such intensity difference at the listening position that according to the sum localization effect z. As a Monosi ^g nal - regardless of listening position - is always heard from the front. Is moving In the system according to the invention, however, a listener in the sound field from the center, for example to the left, the left signal arrives earlier at the new listening position, but the right signal is louder there due to the special directivity of the system. In addition, there is the effect that the right signal does not arrive as late as in the comparison case. If you choose the delays so that the speed of the signal along the loudspeaker chain (track speed) exceeds the airborne sound speed, which is achieved by a preferred setting of the delays, there is a particular advantage of a reduction in the absolute values of the undesired transit time differences that occur on an off-center The listening position between the two stereo signals is created. Compared to a conventional arrangement with two boxes, the level differences required for correct total localization may also be smaller. Which opposite level differences are necessary to counteract the runtime differences. that z. B. the stereo-high center impression is preserved, can be seen from the following examples:

• 1 ms-3 dB; 3 ms-6 dB; 6 ms-9 dB; 10 ms-10 dB.

With a playback system according to the invention, it is possible to generate the aforementioned transit time difference level difference pairings in a listening area area of the size of the square of the stereo base in the sound field itself.

• Es zeigen:
  • Fig. 1 eine Anordnung mehrerer Einzellautsprecher, die mit einem linken und einem rechten NF-Stereokanal verbunden sind, wobei die Schallwellenfront eines Kanals dargestellt ist;
  • Fig. 2 eine Prinzipdarstellung eines HiFi-Turms mit einer Lautsprecherkette, wobei die Schallwellenfronten beider Kanäle dargestellt sind;
  • Fig. 3 eine Lauts^precherkette mit geknickten Schallwellenfronten;
  • Fig. 4 eine Lautsprecherkette mit stetig gekrümmten Schallwellenfronten;
  • Fig. 5 eine Anordnung mit Laufzeitsteller, Frequenzgangsteller und Amplitudensteller;
  • Fig. 6 eine Variante zur Fig.5;
  • Fig. 7 eine alternative Ausführungsform mit einer Verzögerungs-oder Filtereinheit zur Erhöhung der Kanaltrennung;
  • Fig. 8 eine schematische Darstellung zur Verdeutlichung des mit der Ausführungsform der Fig.7 erzielbaren Effekts;
  • Fig. 9 eine praktisch realisierbare Aufstellung der Einzellautsprecher;
  • Fig.lOa-lOc Aufhängevorrichtungen für Einzellautsprecher;
  • Fig.11 eine Detaildarstellung der Haltevorrichtung im Querschnitt;
  • Fig.12 eine Ansicht der Haltevorrichtung von vorn;
  • Fig.13 eine vergrößerte Darstellung der Fig.lOa;
  • Fig.14 eine vergrößerte Darstellung der Fig.lOb;
  • Fig.15 eine vergrößerte Darstellung der Fia.10c.

Exemplary embodiments of the invention are shown in the drawing and are described in more detail below:

• Show it:
  • 1 shows an arrangement of a plurality of individual speakers which are connected to a left and a right NF stereo channel, the sound wave front of a channel being shown;
  • 2 shows a schematic diagram of a hi-fi tower with a loudspeaker chain, the sound wave fronts of both channels being shown;
  • Fig. 3 a Laut ^p computer chain with kinked sound wave fronts;
  • 4 shows a loudspeaker chain with continuously curved sound wave fronts;
  • 5 shows an arrangement with a time-of-flight controller, frequency response controller and amplitude controller;
  • 6 shows a variant of FIG. 5;
  • 7 shows an alternative embodiment with a delay or filter unit to increase the channel separation;
  • 8 shows a schematic illustration to illustrate the effect that can be achieved with the embodiment of FIG. 7;
  • 9 shows a practically feasible arrangement of the individual speakers;
  • Fig.lOa-lOc suspension devices for individual speakers;
  • 11 shows a detailed illustration of the holding device in cross section;
  • 12 shows a view of the holding device from the front;
  • Fig. 13 is an enlarged view of Fig.lOa;
  • Fig. 14 is an enlarged view of Fig.lOb;
  • Fig. 15 is an enlarged view of Fig. 10c.

In Fig.l an arrangement of several individual speakers 1-9 is shown, each of which is assigned a power amplifier 10-18, which serves as a summation amplifier. Each of these power amplifiers 10-18 is connected to the outputs of two preamplifiers 19-27 and 28-36. A series of delay devices 37-45 and 46-54 is connected in series with these preamplifiers 19-27 and 28-36, the delay of which can be set. The delay devices 37-45 are located on the rail 55, into which the LF signals of the left stereo channel are fed, while the delay devices 46-54 are connected to the rail 56, into which the LF signals of the right stereo channel are fed.

For the sake of simplicity, the sound wave front 57 that can be seen in FIG. 1 is only shown for the left channel. It can be seen here that only the loudspeaker 1 transmits its sound wave 58 at time t, while the other loudspeakers due to the delays of the LF signal does not yet emit a sound signal. At time t ₂ , sound wave 58 of loudspeaker 1 has advanced, and sound wave 59 of second loudspeaker 2 is emitted, sound wave 59 at time t _{2 being} shifted from sound wave 58 at time t ₁ by time t ₂ -t _l . This time t ₂ -t ₁ = τ can be set with the aid of the delay device 38. If one now takes into account that the loudspeakers 3-9 receive the signal of the sound wave 58, offset with respect to the preceding loudspeaker by the time τ, the result is an oblique sound wave front, as shown in FIG. This wavefront corresponds to the envelope according to the Huygenian superposition principle. The intensity of this envelope decreases 1 / r, where r is the distance of the wavefront from the loudspeaker. In the area in front of the loudspeaker 1, however, only this acts. This results approximately in a spherical sound wave, the intensity of which decreases with _{1 /} r ² .

Since the time delays caused by the delay devices 37-45 determine the distance between the wave fronts 58 at the different times t ₁ , t ₂ , t ₃ , it can be seen that the inclination of the wavefront line 57 depends on the time delays. The smaller the time delays, the flatter the slope of the wavefront. In the extreme case, ie when there is no longer a time delay, the wavefront is emitted perpendicular to the axis passing through the loudspeakers 1-9. Each of the loudspeakers 1-9 is thus also supplied with the sound signals of the two stereo channels via delay electronics, each via an adding and power amplifier. Each of these speakers 1-9 thus serves to emit both channels simultaneously. The delay electronics achieve a different directivity of the sound radiation despite the radiation from the same loudspeaker chain. The parameters should preferably be selected so that there is an opposite symmetry of the two directional characteristics associated with each channel.

FIG. 2 shows an arrangement in which both the wavefront of the left and the right stereo channel are shown. The figure also schematically shows a hi-fi tower, which consists of a turntable 67, a tuner 68, a cassette player 69, an amplifier 70 and a device 71 for "holophony" - as the type of spatial reproduction of the acoustic signals according to the invention is called - consists.

The L / R signals of the electrical stereo formation are fed from the amplifier 70 to the device 71. The signal is then separated in this device, namely into a lower and an upper frequency range. The lower frequency range - approx. Up to 300 Hz - is fed via lines 72, 73 to normal stereo speakers 74, 75 with good low-frequency reproduction. The higher frequency range of the signal is fed to the speakers 1-9 via a multi-core cable 76 which is looped through the speakers 1-9. This cable 76 is connected to the first loudspeaker 1 and then continued to the last loudspeaker by means of cyclical swapping. In this way, each of the loudspeakers 1-9 receives the signal intended for them from the multi-core cable 76. The wave fronts 77, 78 of the left and right channels now overlap in the manner shown in FIG.

The result is two wavefronts that converge at an angle. Outside the Oberla ^g erungsbereiches, on the outskirts, Ku ^g superimpose elfronten with wavefronts.

Within the triangle 79, which is formed by the base of the chain of speakers 1-9 and by the wave fronts whose extensions intersect speakers 1 and 9, the shorter duration of the signal along the speaker chain makes the differences in the delay and the volume reduced between the two channels so that the spatial sound impression is preserved on every seat within this triangle. Laterally outside of the triangle 79, however, the shorter running time of the near channel is a higher volume, the distant channel compensated. The spherical front of the near channel drops in intensity with 1 / r ² , while that of the distant channel only drops with 1 / r. If stereo signals are added to the chain of loudspeakers 1-9 and the time delays are omitted, a mono signal is generated due to the localization of the sense of hearing. The large number of speakers does not improve the poor sound of the speakers, but rather the direction of the sound. A further improvement in the spatial sound impression can be achieved - as hearing tests have clearly shown - if the time delays are set in such a way that wave fronts 80, 81 result, as shown in FIG. The angle α ₁ can be 14.5 ° and the angle α ₂ 30 °. This requires a variable time delay, as will be explained further below.

The time delay can be realized in that each channel contains an independently adjustable time delay for each loudspeaker. With ten speakers, twenty delays are necessary. However, it is also possible for half of a channel to receive an equal delay from loudspeaker to loudspeaker with the corresponding taps on a time delay IC. With ten speakers, four delay devices or ICs are then necessary. It is also possible to set a constant delay from speaker to speaker. In ten speakers then two deferrers ^g are necessary erungseinrichtungen having ten taps.

In the simplest form, the electronic delay of the LF signal is carried out with bucket chain ICs that have fixed taps (e.g. Reticon R 5201-1 and R 5201-2). As a result, the loudspeakers that are connected to an IC have a constant runtime difference, while the ICs can have different runtimes. If all the running times are constant, the loudspeakers, which are assumed to be a point source of sound, emit a directed wavefront, the Er angle depends on the time delay in the speaker chain. The wave fronts shown in FIGS. 1 and 2 then result. If two delay ICs with five taps each are used per channel, two different transit times can be produced, which cause a kink in the wavefront, as shown in FIG. Such a bend can only be achieved with electronic means if one works for both channels, ie. for the right and left stereo channels, only one loudspeaker chain is used, which emit both channels together. Aligning the loudspeakers or varying the distances between them would influence both channels and would therefore not allow the wavefronts to run against each other.

With completely variable transit times with a delay for each speaker and channel, any bending of the wave fronts 82, 83 is possible. The wave fronts then preferably consist of hyperbolas, as shown in FIG. 4, so that the sound is kissed at a distant focal point (per channel).

In addition, the levels of the left channel decrease from left to right, whereby, for example, 0.5 dB can be set between the speakers. The same happens with the right channel, except that the levels decrease from right to left.

5, each loudspeaker 110, 111-118 is assigned a time-of-flight controller 130, 131-137 for the right channel 122, and a time-of-flight controller 140-147 for the left channel 123. The loudspeaker 110 arranged on the left of the row in the figure does not have a delay time control for the left channel, likewise the loudspeaker 118 located in the row on the right does not have a delay time control for the right channel 122. Furthermore, each speaker has one for the left channel Frequency response controller 150 and an amplitude controller 151 assigned. For the rest, a summation amplifier 124, a level controller 125 and a power amplifier 126 are provided for each loudspeaker. Finally, the system illustrated in Figure 3 is also still equipped with side speakers 110 ', 111' of no further interest here, to which a summing amplifier, a level controller and a power amplifier are also assigned.

The embodiment according to FIG. 6 differs from the embodiment according to FIG. 5 in particular in that the delay adjusters 230, 231 ... 237 or 240, 241 ... 247 assigned to the individual loudspeakers 210, 211 ... 218 are not parallel to each other, but are connected in series. Otherwise, this embodiment does not differ from the embodiment according to FIG. 5, and the same reference numerals are introduced for the same parts as in FIG. 5, but increased by one hundred to distinguish them.

In the embodiments according to the invention according to FIGS. 5 and 6, the delay times of the sound signals can thus be individually adjusted between the loudspeakers, namely in such a way that the sound signal is delayed either from the sound signal source according to the position of the individual loudspeaker along the chain (embodiment according to FIG .5), or in such a way that the delayed sound signals are passed on from speaker to speaker and are further delayed (embodiment according to FIG. 6). Within the scope of the invention, a combination of these two basic possibilities can of course also be realized.

In addition, in the embodiments explained above, the level of the signal components can be set individually per channel and loudspeaker, which was fixed in the simplified embodiment of the invention according to FIG.

Furthermore, the directional characteristic can be set differently using known electronic means for different frequency ranges of the audio signal, which is likewise fixed in the simplified embodiment according to FIG.

With these setting parameters, even when the loudspeakers are not equidistantly positioned, sound fields can be generated which in themselves have the property of enabling stereophonic hearing in a very wide zone in front of and even to the side of a loudspeaker chain. Such a loudspeaker chain arrangement with the associated electronic part, which includes the individual setting of the signal level, frequency response and delay of the tone signal for each loudspeaker, and the joint emission of both channels of a stereo signal by one and the same loudspeaker chain, using the different directivity for both Channels, is a playback system for stereophonic signals, which differs fundamentally from previously known systems.

• Sie ermöglichen auf Hörplätzen außerhalb der Stereomitte bei bester Klangqualität eine erheblich verbesserte Richtungsauflösung bei der wiedergabeintensitätsstereophoner und auch kopfbezogener Stereophonie (im Vergleich zu der herkömmlichen Boxenanordnung). Die bedeutende Verbesserung des stereophonen Hörbildes auf Seitenplätzen wurde in Vergleichsexperimenten durch zahlreiche Versuchspersonen bestätigt. Die Güte der Mittenlokalisation übertrifft diejenige einer üblichen Boxenanordnung, bei der eine geringe Lokalisationsmöglichkeit virtueller Schallquellen in der Mitte als erheblicher Wiedergabemangel allgemein bekannt ist. Die Variabilität der Systemparameter (Anzahl und Position der Lautsprecher, Verzögerung, Pegeleinstellung) erlaubt eine sehr weitgehende Anpaßbarkeit des Systems an die unterschiedlichen akustischen Gegebenheiten in Wiedergaberäumen.

The above-described playback systems according to the aforementioned embodiments are distinguished by the following advantages:

• They enable a significantly improved directional resolution in the reproduction intensity stereophonic and also head-related stereophony (compared to the conventional speaker arrangement) in listening positions outside the stereo center with the best sound quality. The significant improvement of the stereophonic auditory image on the side seats was confirmed in comparative experiments by numerous test subjects. The quality of the center localization exceeds that of a conventional box arrangement, in which a low localization possibility of virtual sound sources in the middle is generally known as a considerable lack of reproduction. The variability of the system parameters (number and position of the loudspeakers, delay, level setting) allows the system to be largely adapted to the different acoustic conditions in playback rooms.

Experiments carried out with embodiments according to the invention have shown that it is sufficient to reproduce the mid-high range in a time-controlled manner, the low range in a special embodiment of the invention being able to be taken over by separate bass radiators. Such an arrangement is characterized in that the Loudspeakers of a loudspeaker chain can be made in a very small design and the mid-high-range radiators can be produced comparatively cheaply, furthermore that the required power amplifiers can be configured with low power, since it is known that the largest part of the power of a broadband loudspeaker arrangement is required for the emission of low frequencies. Due to the small design of the mid-high speakers, they can be installed in rooms in a simple manner and therefore architecturally justifiable.

It is known that measures can be taken on the reproduction side in order to enlarge the subjectively felt width of the stereo base. Such measures usually consist of adding an antiphase component (e.g. left) of the other channel to the signal of one channel, for example the right signal, which can also be delayed and the frequency response changed. The arrangements developed for this purpose generally relate to playback systems in which the two stereo sound signals are fed to separate playback systems.

Playback systems according to the invention thus open up further possibilities for improving the directional resolution by providing an additional delay and / or filter unit in the electronic part for the purpose of increasing the channel separation for the listener. Such a playback system is shown in Fig.7. The requirements to be placed on the delay and _/ or filter unit can be determined in an experiment by subjective listening tests and objective measurements using an artificial head.

In the embodiment illustrated in FIG. 7, the loudspeakers 310 ... 315 are fed from the left via the channel 323 with the signal 2L-R and from the right via the channel 322 with the signal 2R-L, furthermore also starting from the middle of the Chain with a delayed sum signal L _T + R _T that is delayed so that it is something arrives at a middle listening position later than the other two signals. The signal addition (2L-R) + (2R-L) = (2R _t 2L) results for the listener at this middle listening position, which gives a central impression. However, the listener also receives the delayed signal components (R _T + L _T ) from the center, which increases the central impression and makes the localization of the center more precise. In the case of a conventional box arrangement, the specifying signal (R _T tL _T ) is naturally missing. In the case of a pure right signal, the listener initially receives the signals (2R) + (-R) in the middle position, which determines the direction "right" due to the higher level of 2R. The delayed portion R _T from the center hardly changes this impression, since the law of the first wavefront is known to be effective. If the listener is on a side position to the right of the middle level and a left signal is to be reproduced, (-L) comes first, the signal (t L _T ) is somewhat delayed and the signal (2L) a little later. The latter occurs firstly with a high signal level and secondly with a high level in the sound field as a result of the focusing directivity of the loudspeaker chain, which leads to the overall directional impression "left". In practical experiments it has been shown that the signals for good directional resolution, not as selected here for simplified illustration, are (2R-L) or (2L-R) optimal, but (2R-kL) or (2L-kR) with k <1 and c (L _T + R _T ) with c <2.

The schematic representation according to Fig. 8 gives the directional impression.

In a further special embodiment, systems according to the present invention can be used not only for spatial reproduction but also for the production of special subjective listening effects. If you change the delay times of the signal during operation of the system, which can be done automatically or manually according to a certain law, the entire audio picture naturally changes. The known Doppler effect occurs in the case of rapid changes, while the changes occur in the case of slow changes Doppler effect remains inaudible, the listener subjectively experiences a hardly describable "turning" of the audio picture, as the virtual sources constantly change their location.

A realizable construction of the arrangement according to the invention is shown once again in FIG. One can recognize here again a turntable 84, a tuner 85, an amplifier 86 and a holophonic device 87, which are stacked one above the other and are located on a table 88. A plurality of tweeter and midrange speakers 90-98 are set up on a platform 89, which are connected to one another by a cable that is not visible in the platform 89. Two standard speakers 99, 100 with woofers are arranged next to the speakers 90-98.

The volume of all loudspeakers 90-100 is adjusted with the amplifier 86, as is the sound, the rumble-thump filter and the balance. However, the balance is no longer required in the invention.

In the holophonic device 87, the volume between the loudspeakers 99, 100 and the loudspeakers 90-98 and the delays can be set.

The loudspeakers 90-98 can be normal broadband loudspeakers, but they are expediently designed as mid-high-range speakers from approx. 200 to 300 Hz, since lower frequencies hardly contribute to localization. Accordingly, the loudspeakers 99, 100 can be trimmed to the appropriate (200 to 300 Hz) upper cut-off frequency with a passive or active bass. This allows z. B. the arbitrary placement of mostly large speakers 99, 100 in the living room, while the small speakers 90-98 should be aligned in a straight line.

The entire arrangement is about 3m to 4m wide with nine speakers 90-98.

The delay time of the left and right channels is freely selectable for each loudspeaker, based on loudspeakers 99, 100 and 90, 98, which are each instantaneous. The subsequent preamplifiers are used to set the level for each speaker and channel, independently of one another, based on the level of speakers 99, 100 or 90, 98.

FIGS. 10a-10c show in principle how the loudspeakers 90-98 shown in FIG. 9 can also be attached to a wall using a rail or the like. 10 a shows a loudspeaker 101 which has an opening 102 which is slipped over a carrier 103, this carrier 103 being part of a holding device 105 which can be connected to a wall 104. This holding device also has a cable duct 106 and an obliquely aligned support rail 107.

With the aid of the carrier rail, it is possible, as shown in FIG. 10b, to arrange the loudspeaker 101 at an angle by pushing the carrier rail 107 into the opening 102. By rotating the speakers 180 ⁰ or provided with a second opening, it can also be hung from the ceiling 108th This is shown in Fig.lOc. The carrier 103 is used here as a means for fastening the holding device 105 to the ceiling.

The device shown in FIGS. 11 and 12 for suspending a loudspeaker L on a surface 10 consists of a profile rail 401 which has two shafts 409 separated by walls 402. Both shafts 409 are each provided with an opening 403 leading to the outside. Between the walls 402, the profile rail 401 has at least two openings 404 which are spaced apart in one plane and to which central openings 405 are assigned, the diameter of the openings 404 being larger than that of the assigned openings 405. Averted from the suspension surface 410, the leg 406 is arranged at right angles to the profile rail 401 and is provided with an opening 408 in the center of the leg edges.

At the other end of the profile rail 401 there is a leg 407 which forms an angle α of 120 ° with respect to the profile rail surface lying between the legs.

The opening 404 serves to introduce a screw which is screwed into the wall through the associated opening 405. The openings 403 serve to guide the cable into and out of the shafts 409.

The leg 406 either serves to attach a loudspeaker L parallel to the profile rail 401 or to fasten the profile rail to a ceiling surface 411 by means of a screw passed through the opening 408.

The leg 407 is used to attach a loudspeaker L at an angle to the profile rail 401.

The loudspeakers L are each provided with a groove 412 on the back so that they can be plugged onto the legs 406 or 407.

The speakers are clamped to the profile rail 401 by means of a screw (not shown) attached to the underside of the loudspeaker.

FIG. 13 shows a loudspeaker L suspended from the vertical wall 410 by means of the profile rail 401, the loudspeaker being attached to the leg 406. The cable K is guided through the opening 403 of the shaft 409 assigned to the leg 406. This type of attachment of the loudspeaker is expediently carried out at ear level.

FIG. 14 shows a loudspeaker L attached to the leg 407 of the profile rail 401 fastened to the wall in the same way as in FIG. 12, the cable routing likewise being carried out by the Opening 403 of the shaft 409 associated with the leg 406 takes place. The type of attachment of the loudspeaker is conveniently at the top of the vertical wall surface 410.

15 shows the profile rail 401, fastened to a ceiling 411 by means of a screw which is passed through the opening 408 of the leg 406. The loudspeaker L is mounted on the leg 407. The cable is routed through the opening 403 of the shaft 409 assigned to the leg 407.

You can arrange several loudspeakers in a row, as well as various arrangement options for the loudspeaker series in height and on the ceiling. Installation is possible without the cabling affecting the view. The security concerns have been resolved.

Claims (33)

1. Arrangement for acoustic reproduction of signals which can be represented by means of a right and a left stereo channel (R, L), this arrangement comprising a plurality of individual speakers (1-9; 90-98; 99, 100), at least of which some (1-9; 90-98) are connected to the right and left stereo channels (R, L) via delay devices (37-45; 46-54), characterized in that the left stereo signal (L) is a single speaker (1 -9; 90-98) with a respective first delay assigned to this loudspeaker (eg 3) and that the right stereo signal is supplied to an individual loudspeaker (1-9; 90-98) with a second delay respectively assigned to this loudspeaker (eg 3) is, the delays of the right and left stereo signals are dimensioned so that the waves emitted by the individual speakers (1-9; 90-98) form two wave fronts (80, 80 '; 81, 81'). 2. Arrangement according to claim 1, characterized in that the delay times of the delay devices (37-45; 46-54) are adjustable. 3. Arrangement according to claim 1, characterized in that the individual speakers (1-9; 90-98, 99, 100) supplied signals are adjustable in terms of their level and / or their frequency response. 4. Arrangement according to claim 1, characterized in that the delay times of the delay devices (37-45; 46-54) LF frequency are adjustable. 5. Arrangement according to claim 1, characterized in that the delay times of the delay devices are a linear or non-linear function of the spatial arrangement of the individual speakers (1-9; 90-98). 6. Arrangement according to claim 1, characterized in that the individual speakers (1-9; 90-98) are arranged equidistantly on a horizontal line. 7. Arrangement according to claim 6, characterized in that the line is a straight line. 8. Arrangement according to claim 5, characterized in that the delay times are a function of the distance of any single speaker (z. B. 6) to the first single speaker (1). 9. Arrangement according to claim 1, characterized in that the left and the right stereo signal are the LF signals of a power amplifier or the like. 10. The arrangement according to claim 1, characterized in that the respective individual speakers (1-9; 90-98; 99, 100) supplied signals have amplitudes that a function of the spatial arrangement of the speakers (1-9; 90-98; 99, 100). 11. The arrangement according to claim 1, characterized in that the signals supplied to the respective individual speakers (1-9; 90-98; 99, 100) have amplitudes which are a function of the delay times. 12. The arrangement according to claim 1, characterized in that the signals supplied to the individual loudspeakers (1-9; 90-98; 99, 100) have amplitudes which are a function of the signal frequencies. 13. Arrangement according to claim 1, characterized in that sum amplifiers (10-18) are provided between the loudspeakers (1-9; 90-98) and the respectively assigned delay devices (37-45; 46-54). 14. Arrangement according to claim 1, characterized in that a device for increasing the channel separation is provided for the listener. 15. The arrangement according to claim 1, characterized in that the loudspeakers (1-9; 90-98) supplied signals are changeable during operation. 16. Arrangement according to claims 1 and 13, characterized in that the delay devices (37-45; 46-54) each have an amplifier (19-27; 28-36) connected downstream and that the outputs of these downstream amplifiers (19-27 ; 28-36) are interconnected and fed to a summation amplifier (10-18). 17. The arrangement according to claim 1, characterized in that the left and right stereo signals are each fed to a crossover (71) which separates the lower frequencies up to about 300 Hz and each feeds a woofer (74, 75), and that the remaining frequencies about deferrers ^g erungseinrichtungen (37-45; 46-54) are fed to the individual loudspeakers (1-9). 18. Arrangement according to claims 1 and 17, characterized in that the speakers (1-9; 90-98) are mid-high speakers with a frequency range of about 300 Hz to 25 Hz. 19. The arrangement according to claim 1, characterized in that the delay devices (37-45; 46-54) are bucket ice circuits. 20. The arrangement according to claim 1, characterized in that the individual speakers are connected to each other via a multi-core cable (76), the number of wires of which is proportional to the number of speakers, this cable being fed to the first speaker (1) and from speaker to Loudspeaker is cycled until the last loudspeaker (9) is continued. 21. Arrangement according to claims 1, 13 and 16, characterized in that the amplifiers (19-27; 28-36; 10-18) have an adjustable gain per channel before the summation. 22. Arrangement according to claims 1, 10, 13, 16 and 21, characterized in that the gain is a function of the distance of the associated speaker (z. B. 6) from the first speaker (z. B. 1). 23. The arrangement according to claim 1, characterized in that the individual speakers (1-9; 90-98) are fastened to a converting element (104) or the like with the aid of a holding device (105). 24. The arrangement according to claim 1, characterized in that the running times of the delay devices (37-45; 46-54) are set so that there is a flat sound wave front for each channel. 25. The arrangement according to claim 1, characterized in that the running times of the delay devices are set so that curved sound wave fronts result. 26. The arrangement according to claim 25, characterized in that the sound wave fronts (82, 83) are convexly curved in the direction of the listening room. 27. The arrangement according to claim 26, characterized in that the sound wave front consists of two straight pieces (80, 80 '; 81, 81') which each enclose an angle (dl, d2). 28. The arrangement according to claim 26, characterized in that the sound wave front has a parabolic curvature. 29. The arrangement according to claim 26, characterized in that the sound wave front (82, 83) has a hyperbolic curvature. 30. The arrangement according to claim 25, characterized in that the sound wave front has a circular curvature. 31. The arrangement according to claim 1, characterized in that the individual speakers sum and / or difference signals and / or center signals and / or combinations of these signals are supplied in such a way that two arbitrarily curved and overlapping wave fronts result. 32. Arrangement according to claim 23, characterized in that a profile rail (401) has at least one leg (406) arranged vertically to the profile rail surface and underneath at least one further leg (407) which is at an angle (d) from the profile rail surface lying between the legs Forms 120 ° to 150 °, and the leg (406) arranged vertically to the profile rail surface is provided with an opening (408) in the center of the leg edges. 33. Arrangement according to claim 32, characterized in that the profiled rail (401) has two shafts (409) separated by at least one wall (402) and both shafts (409) are each provided with an opening.

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