EP1216600B1 - Multiple speaker - Google Patents

Abstract

The invention relates to a loudspeaker combination comprised of at least two loudspeakers, of which one is preceded by a low-pass frequency filter, the other by a phase shifter in the form of an all-pass filter. The invention addresses the problem of providing with simple means a configuration simple of realization of such a loudspeaker combination, whose frequency response and whose radiation characteristic is significantly improved. The invention resides therein that the other loudspeaker or the other loudspeakers is/are each preceded by at least one phase shifter, with all phase shifters being tuned with respect to their phase setting to the phase position of the loudspeakers radiating lower tones, such that all loudspeakers radiate the low tones in like phase position. The fundamental idea is herein: several primarily identically structured loudspeakers can be employed, all or at least the major portion of the loudspeakers are allowed to transmit low tones, with the loudspeakers, which, in addition to the low frequencies, also have to transmit higher frequencies, being changed in their phase position such that the low and the particular lower frequencies are radiated in identical phase position. A large loudspeaker area therein transmits the low frequencies, a smaller the medium and high frequencies. This yields better transmission results than can be attained with loudspeakers laid out in their structural form for separated frequency ranges. Hereby the technical expenditures are low, the possibly attainable improvement of radiation characteristics, however, is remarkable.

Description

The invention relates to a loudspeaker combination consisting of at least two loudspeakers, one of which is preceded by a low-pass frequency filter and the other a phase shifter.

Such a speaker combination is from the DE 44 47 269 C1 Fig. 2 known. As is customary in such speaker combinations, the electrical signals to be converted into acoustic signals are fed to two loudspeakers, wherein one loudspeaker is preceded by a low-pass filter, the other loudspeaker is preceded by a high-pass filter, so that the low frequencies are used with one loudspeaker and the high frequencies with the other loudspeaker be radiated. Since this form of frequency division and frequency separation is unsatisfactory, a phase shifter has been arranged between the high-pass filter and the tweeter with which the phase position of the tweeter signal is rotated by 180 °. This rectangle pulses are to be played satisfactorily, for music and voice transmission, the transmission quality is unsatisfactory.

Another circuit for frequency division is from the DE 28 02 938 A1 become known, in which a separate low-pass filter is provided for each frequency range, each having an addition circuit for a feedback of inverted signals from the next lower Frequency range is preceded so that each frequency range only frequencies associated with it, but not also frequencies from a neighboring area.

For sound transducers for the transmission of music and speech signals generally there are the requirements for specified sound pressure over wide frequency ranges, low natural oscillations and resonance, linear characteristic, a broad transmission range, low production costs and for use as a public address system in event rooms, public buildings, etc. in addition, the demand for a uniform frequency-independent sound bundling and as far as possible adjustable beam angle for different applications with the smallest possible dimensions. Although some of these demands can now be achieved with today's converters and the use of additional electronics, but so far no converter is known that satisfies all the above requirements in a satisfactory manner.

To solve the above-mentioned problems, various approaches have been implemented in the past.

For the consumer sector systems are generally used in which the frequency band to be transmitted is divided into several bands and assigned to several membranes of different sizes. Large and heavy membranes transmit the low frequency range, smaller lighter membranes transmit the higher frequency ranges. From this construction, the problem arises of different bundling factors, phase responses and group delay of the individual systems, so that resulting discontinuities in the emission and transition area can be avoided. In addition, there are interferences between the systems and outside of the Main radiation axis to discontinuities in the transmission measure.

Since loudspeakers of known types do not meet the requirements for a high quality of voice and sound transmission, numerous attempts have been made to improve the transmission quality by combining loudspeakers of different and the same type with and without upstream frequency filters. In these designs, there is also the problem of different bundling factors, phase responses and group delays of the individual systems and thus there are discontinuities in the radiation and transmission behavior of the overall system in the transition region. In addition, interference between the systems outside the main radiation axis leads to discontinuities in the transmission measure.

The invention avoids the disadvantages of the prior art. It is the object of the invention to provide a simple combination of a speaker combination, the frequency response and radiation characteristics is significantly improved and reaches a good sound quality in the low frequency range without special woofer

The invention consists in that, of the at least two loudspeakers, at least one, which is preceded by the low-pass frequency filter, transmits only tones of the low-frequency range because of this low-pass frequency filter, and at least one other, preceded by the phase shifter, both tones of this low-frequency range Also, at least tones of medium frequencies radiates, and that this both low-frequency sound and mid-frequency sounding speakers in the phase adjustment of its low frequency range by the phase shifter on the phase of the only sounds of the low tone range radiating speaker is tuned.

Through the application and combination of these technical features, it is no longer necessary to use special very large and therefore sluggish and expensive woofers with high-weight membranes to achieve good sound quality in the low frequency range, but you can build more equal, because of their lighter membranes use faster-responding speakers of a low-cost design to radiate with these all the low tones, while the middle and high tone ranges can be radiated with only a part of the speakers, Here transmits a large in-phase radiating speaker surface, the low tones, while a smaller speaker surface, the middle and radiates high frequency ranges. This results in better transmission results than can be achieved with designed for separate frequency ranges in their design speaker combinations.

The simplest embodiment of the invention consists in that the loudspeaker combination of the two loudspeakers, one of which is preceded by only one low-pass frequency filter so that it emits only tones of the low-frequency range, and the other loudspeaker alone is preceded by a phase shifter, so that it tones both the middle and the low tone range radiates, and that this sound of both the low and the middle tone range radiating speakers is tuned in the phase adjustment of its low frequency range by the phase shifter on the phase of the woofer.

As a result, the technical complexity is low, the possible improvement of the radiation characteristics, however, striking. The phase adjustment is ok in a simple manner. This achieves a slight adaptation to the respective room to be sounded. Despite the low effort, the speech intelligibility and the music suitability is significantly improved. It achieves a largely frequency-independent bundling of sound radiation without pronounced side lobes. It is achieved a very homogeneous and interferrenzarmes radiation behavior.

The basic idea of the invention is: It is possible to use a plurality of principally identically constructed loudspeakers, all or at least the majority of the loudspeakers can transmit the low tones, whereby the loudspeakers, which in addition to the low frequencies also have to transmit higher frequencies, change their phase position be that the low frequencies of all speakers that emit low frequencies are radiated in the same phase. A large loudspeaker area transmits the low frequencies, a smaller one the medium and high frequencies. This results in better transmission results than can be achieved with designed for separate frequency ranges in their design speakers.

To be able to produce this speaker combination very inexpensively, it is advantageous that at least one of the sounds of the middle frequency range radiating speakers this speaker combination of the same design and design as the speaker with the upstream low-pass is. The use of industrial mass production loudspeakers is thus possible and, in addition to the technical advantages mentioned, also leads to economic advantages.

Another embodiment of the invention with a division of the low frequency range is that in addition to the speaker combination in which a low-pass filter and the other second loudspeaker an all-pass filter is preceded by phase shifter, another, additional third sounds in addition to tones middle frequency also tones of the woofer radiating speaker is provided with upstream all-pass filter, that in addition to the second loudspeaker upstream all-pass filter, a low-pass filter is connected upstream, but compared to the first speaker upstream low-pass filter has a higher upper pass frequency, and that the additional third speaker to the all-pass filter another all-pass filter is preceded by phase shifter, said one all-pass filter in its phase position on the first loudspeaker upstream low-pass filter and the other all-pass filter is tuned to the second loudspeaker upstream low-pass filter, while d the all-pass filter before the time speaker is tuned to the low-pass filter in front of the first loudspeaker in its phase position.

The three speakers of this speaker combination amplifier can be connected upstream as active switching elements, in such a way that a loudspeaker amplifier is preceded by a low-pass filter, the second speaker with amplifier, a low-pass filter and in its phase on the low-pass filter of the former speaker tuned all-pass filter with phase shifter upstream, that is supplied via a tap between the all-pass filter and the low-pass filter of the second loudspeaker equipped with the amplifier third speaker, which is preceded by an all-pass filter, this all-pass filter is tuned to the low-pass filter before the former speaker.

In this speaker combination, the speaker (s) connected to the low-pass filter and the speaker (s) connected to the phase shifter may be identical or very similar in their type and size. This provides not only price advantages when purchasing larger quantities of speakers of the same type, but also acoustic benefits of various kinds. Deep tones are emitted from several speakers in phase, high tones only from a single speaker or a few speakers the same radiation characteristics.

This speaker combination becomes very simple when the phase shifter is an all-pass filter with a phase shifter.

With this speaker combination it is quite possible and for larger systems it is recommended that several loudspeakers are connected to the low-pass filter and / or several loudspeakers to the phase shifter.

For higher sound power and improved sound quality, it is advantageous if a further loudspeaker is provided in this combination, which has both a low-pass filter, However, with a higher upper pass frequency, as well as a phase shifter is connected upstream, which is tuned in its phase adjustment to the phase of the woofer, and that at least one tweeter with upstream high-pass filter is also provided in this speaker combination.

It is expedient if the all-pass filter is constructed entirely of passive switching elements. The all-pass filter can also be constructed of active and passive switching elements.

Further, it is advantageous if the two identical or very similar speakers, one of which a low-pass filter, the other a phase shifter is connected upstream, are housed together with a tweeter in a common housing.

The speaker combination may also be a speaker line in which the speakers are housed in an elongated housing and form a speaker line.

In the case of a loudspeaker line, it is advantageous if the woofer is arranged at the ends or at the outer sides of the loudspeaker line.

Fig.1

Die Basisschaltung mit zwei gleichgebauten Lautsprechern, betrieben mit passiven Filtern.

Fig.2

Die Basisschaltung mit zwei gleichgebauten Lautsprechern, betrieben mit aktiven Filtern.

Fig.3

Eine Schaltung mit drei gleichen Lautsprechern, betrieben mit passiven Filtern.

Fig.4

Die Schaltung mit drei gleichen Lautsprechern, betrieben mit aktiven Filtern.

Fig.5

Die um einen zusätzlichen Hochtöner erweiterte Grundschaltung.

Fig.6

Die in der Lautsprecheranzahl verdoppelte Basisschaltung.

The essence of the invention is explained below with reference to exemplary embodiments schematically illustrated in block diagrams in the drawing. It demonstrate:

Fig.1

The basic circuit with two identical loudspeakers, operated with passive filters.

Fig.2

The basic circuit with two identical loudspeakers, operated with active filters.

Figure 3

A circuit with three equal loudspeakers, operated with passive filters.

Figure 4

The circuit with three equal loudspeakers, operated with active filters.

Figure 5

The basic circuit extended by an additional tweeter.

Figure 6

The doubled in the number of speakers base circuit.

The loudspeaker combination according to the invention consists in its in Fig.1 and 2 shown base circuit of two identically built, built in a housing 1 speakers 2.3, of which a loudspeaker 3 is a low-pass frequency filter 4 is connected upstream. The other loudspeaker 2 is preceded by an all-pass filter 5 with a phase shifter, which is tuned in its phase adjustment to the phase position of the loudspeaker 3 intended for the emission of deep tones. Although both speakers are 2.3 of the same design and design and are not built specifically or only to a limited extent for the emission of low frequencies and are well suited for the radiation of medium frequencies in their geometric design, is in this combination with the assumption of a suitable phase matching of the Allpass filters 5 a better radiation result achieved when using different, adapted to specific frequency ranges speakers.

In her in Fig.2 In the embodiment shown, the amplifiers 6, 7 are added to the passive components as active components.

In Figure 3 is the speaker combination opposite the base circuit ( Fig.1 ) To another speaker 8, also of the same design and design as the speakers 2 and 3, extended. In this combination, in which the speaker 3 as in the basic circuit of Fig.1 a low-pass filter 4 and the loudspeaker 2 an all-pass filter 5 is connected upstream with phase shifter, in addition to the all-pass filter 5 is preceded by a low-pass filter 9, however, compared to the low-pass filter 4 has a higher upper pass frequency. The additional loudspeaker 8 are now preceded by two additional all-pass filters 10 and 11 with phase shifters. The all-pass filter 10 is tuned in its phase to the loudspeaker 3 upstream low-pass filter 4 and the all-pass filter 11 on the speaker 2 upstream low-pass filter 9, while the all-pass filter 5 is tuned as in the base circuit to the low-pass filter 4 in its phase position. In this combination, assuming a suitable phase adaptation, the all-pass filter 5, 10, 11 achieves a better radiation result than when different loudspeakers adapted to specific frequency ranges are used.

In this speaker combination, e.g. the low-pass filter 4 to be designed for an upper pass frequency of 250 Hz and the low-pass filter 9 to an upper pass frequency of 500 Hz.

The equipped with active components, in Figure 4 shown embodiment of a speaker combination with three identical speakers is constructed somewhat differently than in Figure 3 shown embodiment with only passive components:

Each of the three loudspeakers 2, 3, 8 is preceded by an amplifier 6, 7, 12 as an active element. The loudspeaker 3 with amplifier 7, as in the basic circuit, only a low-pass filter 4 upstream of the speaker 2, a low-pass filter 9 and a matched in its phase on the low-pass filter 4 all-pass filter 5 with phase shifter. Via a tap between the all-pass filter 5 and the low-pass filter 9, the equipped with the amplifier 6 speaker 8 is supplied to an all-pass filter 11 is connected upstream. This is matched to the low-pass filter 9, while the all-pass filter 5 is tuned to the low-pass filter 4.

In the embodiment of the Fig. 5 In addition to the identically constructed loudspeakers 2 and 3, a tweeter 14 is also installed in the housing 1. This is preceded by a high-pass filter 13, for example, passes frequencies higher than 2 KHz. The loudspeaker 3 is preceded by a low-pass filter 4 with an upper pass frequency of 500 Hz, for example, and this is another Low-pass filter 15 upstream with an upper pass frequency of 2 KHz. The loudspeaker 2 is connected to an all-pass filter 5 with phase shifter and this to a tap between the two low-pass filters 4 and 5.

Figure 6 shows the basic circuit of Fig.1 with a doubled number of speakers in a housing 1, in which the depth radiating speakers are arranged on the outsides of the speaker line.

Filters which can also be used are those which digitally process signals and audio pulses of different frequencies.

List of reference numbers

1

casing

2

speaker

3

speaker

4

Low-pass frequency filter

5

All-pass filter with phase shifter

6

amplifier

7

amplifier

8th

speaker

9

Tiefpaßfrequenzfilter

10

All-pass filter with phase shifter

11

All-pass filter with phase shifter

12

amplifier

13

highpass filter

14

tweeter

15

low pass filter

Claims (9)

1. Loudspeaker combination, consisting of at least two loudspeakers (2, 3), a low-pass frequency filter (4) being connected upstream from one (3) of the loudspeakers and a phase shifter (5) being connected upstream from the other (2), characterised in that of the at least two loudspeakers (2, 3) at least one, upstream of which the low-pass frequency filter (4) is connected, radiates only tones of the base range because of this low-pass frequency filter (4), and at least another loudspeaker, upstream of which the phase shifter (5) is connected, radiates both tones of this base range and also at least tones of medium frequencies, and in that this loudspeaker (2) radiating both tones of the base range and also tones of medium frequency is tuned with respect to the phase adjustment of its base range by the phase shifter (5) to the phase position of the loudspeaker (3) radiating only tones of the base range.
2. Loudspeaker combination, consisting of at least two loudspeakers (2, 3), a low-pass frequency filter (4) being connected upstream from one (3) of the loudspeakers and a phase shifter (5) being connected upstream from the other (2), characterised in that in this loudspeaker combination of the two loudspeakers (2, 3), only a low-pass frequency filter (4) is connected upstream from the one loudspeaker (3), so it only radiates tones of this base range, and only a phase shifter (5) is connected upstream from the other loudspeaker (2), so it radiates tones both of the medium and also the base range, and the loudspeaker (2) radiating both tones of the base and also of the medium tone range is tuned with respect to the phase adjustment of its base range by the phase shifter (5) to the phase position of the base loudspeaker (3).
3. Loudspeaker combination, consisting of two loudspeakers (2, 3), a first low-pass filter (4) being connected upstream from a first (3) of the loudspeakers and a phase shifter (5) being connected upstream from a second loudspeaker (2), characterised in that in this combination, the phase shifter (5) is implemented by a first all-pass filter and a further, additional loudspeaker (8) also radiating tones of the base range in addition to tones of the medium frequency is provided with an upstream second all-pass filter (10), in that, in addition to the first all-pass filter (5) upstream from the second loudspeaker (2) a second low-pass filter (9) is connected upstream, which has, however, a higher upper pass frequency compared to the first low-pass filter (4), and in that a further third all-pass filter (11) with a phase shifter is connected upstream from the additional loudspeaker (8) to the second all-pass filter (10), wherein the second all-pass filter (10) is tuned with respect to its phase position to the low-pass filter (4) connected upstream from the first loudspeaker (3) and the third all-pass filter (11) is tuned to the low-pass filter (9) connected upstream from the second loudspeaker (2), while the first all-pass filter (5) is tuned to the first low-pass filter (4) with respect to its phase position.
4. Loudspeaker combination, consisting of at least two loudspeakers (2, 3, 8), in which amplifiers (6, 7, 12), as active circuit elements, are connected upstream from the loudspeakers (2, 3, 8), only a first low-pass filter (4) being connected upstream from a first of these loudspeakers (3) with amplifier (7) a second low-pass filter (9) and a first all-pass filter (5) with phase shifter being tuned with respect to its phase position to the first low-pass filter (4), in that a third loudspeaker (8) equipped with an amplifier (6) is supplied via a tap between the first all-pass filter and the second low-pass filter (9) a second all-pass filter (11) being connected upstream from said loudspeaker, said all-pass filter being tuned to the second low-pass filter (9) with respect to its phase position, while the first all-pass filter (5) is tuned to the first low-pass filter (4) with respect to its phase position.
5. Loudspeaker combination according to any one of claims 1, 2, 3 or 4, characterised in that at least one of the loudspeakers (2, 8) also radiating tones of the medium frequency range, of this loudspeaker combination, is of the same type and form of construction as the loudspeakers (3) with the upstream low-pass (4).
6. Loudspeaker combination according to any one of claims 1, 2, 3 or 4, characterised in that all or at least a plurality of loudspeakers (2, 3, 8) of this loudspeaker combination have an identical or at least very similar frequency characteristics.
7. Loudspeaker combination according to any one of claims 1, 2, 3 or 4, characterised in that all or at least a plurality of loudspeakers (2, 3, 8) of this loudspeaker combination are of the same type and form of construction.
8. Loudspeaker combination according to any one of claims 1, 2, 3 or 4, characterised in that the phase shifter (5) is an all-pass filter with a phase displacement member.
9. Loudspeaker combination according to any one of claims 1, 2, 3 or 4, characterised in that, in addition, at least one treble loudspeaker (14) with an upstream high-pass filter (13) is provided in this loudspeaker combination.

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