DE10256448A1 - Two-way or multi-way loudspeaker has dynamic loudspeaker section and high-frequency unit formed by piezoelectric loudspeaker with piezo element firmly attached to center of diaphragm - Google Patents

Abstract

The loudspeaker has a diaphragm (2) connected to a voice coil (6) in the air gap of an annular permanent magnet (9). The loudspeaker has a high frequency section which is formed as a piezoelectric loudspeaker with a piezo element (13) firmly attached to the diaphragm and carried by it. The piezo element is preferably arranged in the center of the diaphragm.

Description

The present invention relates to a two- or multi-way speaker system with a tweeter element and another speaker element with a membrane as dynamic Transducers such as dome or cone speakers, in which the membrane is connected to a voice coil that is in the field of a magnet located, especially in the air gap of an annular permanent magnet surfaced.

A single dynamic converter is mostly unable to replay all frequencies of the audio spectrum to give. For high frequencies become very small due to the low moving mass Transducers, such as calottes, are preferably used. For deep Frequencies are due to poor dynamic coupling to the air, rather large and thus used heavy cone speakers. The mass of inertia a cone speaker is so high that it has insufficient high frequencies can play. Even broadband speakers, especially in the lower one Price segment, solve this problem is insufficient. In addition, the bass reproduction is such wide belts limited due to the mostly short and therefore light voice coil. Broadband speakers belong among the cheapest in terms of price and least vulnerable Speakers.

Therefore, usually reusable systems consisting of components optimized for frequency range. A classic variant of such a reusable system is the Two-way speaker. It consists, for example, of a small, light tweeter as a tweeter and a large and therefore heavy cone speaker as woofer. The problem with these Systems is that the sound does not come from one place because the tweeter next to the woofer sitting. This has the consequence that between the two speakers Interferences arise that adversely affect the directivity and affect the sound. Mechanically there are more problems here to solve than with a broadband. In addition, there is also very high circuit complexity, such as Crossovers and cabling. All of this is reflected also in manufacturing costs again.

From a tonal point of view would be a punctate Sound source that emits all frequencies ideally. This was alongside tried to solve the broadband speakers with coaxial systems those of the tweeters arranged in the middle of the woofer is. There are two variants. At the first, in the professional The tweeter sits behind the PA area of the predominantly used variant the magnet of the woofer, shines through a hole in the magnet and uses the membrane of the woofer as a horn. Since the diaphragm of the woofer moves, this variant has however, the disadvantage that the horn for the tweeter also moves. That is, there is never an optimal horn for that Tweeter.

In the second variant, a Tweeter the membrane of the woofer set. This creates a disturbing element in front of the membrane Woofer. This structure is bad in principle, because the tweeter is the Sound propagation of the frequencies emitted by the membrane is impeded. Unavoidable reflections on the tweeter result in runtime errors, which result in phase cancellations reflect. With all Coax systems is also an increased There is a risk of contamination because dirt gets into the woofer magnet system can because the dust cover is missing. The mechanical and circuit complexity is also quite high here.

The invention is based on the object Two-way or multi-way speaker system of the type mentioned above, which does not have these disadvantages having. In particular, the sound source for all frequencies should essentially be from come to a location so that the phase alignment is optimized can. The construction should also be as inexpensive as possible.

This task is solved in that the tweeter element is designed as a piezoelectric loudspeaker is, the piezo element with the membrane of the further speaker element connected vibration-proof, in particular is supported by this.

Thanks to the vibration-proof connection of the tweeter with the membrane of the further loudspeaker element, for example woofer, is advantageously achieved that the location of sound generation for all Frequencies is essentially the same. The piezo element of the piezoelectric Tweeter the advantage that it is very light and therefore practically none additional Weight for the membrane of the woofer means. The woofer is practically not additionally loaded by the piezo element. In this way, a speaker system can be created which a quasi punctiform Sound source for represents all frequencies, with the phase adjustment between tweeter and woofers can be optimized. In addition, this system is by use of a piezoelectric tweeter and the structure according to the invention relatively inexpensive.

The arrangement is particularly advantageous of the piezo element in the center of the membrane, since this is the training a quasi punctiform Sound source best approximated can be.

A thin disk or can be used to arrange the piezo element in the center of the membrane a calotte can be provided, through which the piezo element is carried. This can be the normal dome of the loudspeaker element, for example a woofer, which in conventional loudspeaker systems serves as a dust protection cover for the magnetic gap of the loudspeaker element. An HF conductive material should be used.

The piezo element is also preferred on the back side the thin Disc or dome arranged. It is therefore against influences from protected outside.

Through another disk or dome, which the piezo element together with the first disc or dome encloses on all sides, the piezo element can be further protected. In particular, it can also pressure fluctuations in the space between the piezo element and the magnet system be excluded.

It is also advantageous if only the piezo element is vibration-proof with the membrane further Speaker element is connected. The remaining components of the tweeter element, especially transformer coil, can then preferably on the magnet of the further loudspeaker element or whose basket can be arranged. This will make the membrane additional to be worn Weight if possible kept low so that the sound behavior is affected as little as possible.

For connecting the piezo element with the membrane of the further loudspeaker element, it can be after a preferred embodiment of the invention with the disc or The cap is glued. This is not a problem in production and guaranteed a good and lasting connection.

An embodiment of the invention is shown in the drawing and is described below. They show, each in a schematic representation,

1 a cross section through a speaker according to the invention, and

2 the detail A from 1 in an enlarged view.

The in 1 loudspeaker shown includes a basket 1 , for example made of metal, which essentially has the shape of a funnel with a perforated funnel wall. In the basket 1 is a bass cone 2 clamped, which is also essentially funnel-shaped and whose edge is larger in diameter 3 , which forms the sound outlet side, over undulating corrugated beads 4 with the basket 1 connected is.

The inner edge 5 the membrane 2 carries a voice coil 6 and is over a wavy centering membrane 7 with the inside of the basket 1 connected. The voice coil 6 dives into the air gap 8th one on the back of the basket 1 arranged permanent magnets 9 , Over wires 10 is the voice coil 6 connectable to a low current circuit.

In the area of the inner end 5 the bass cone 2 is a calotte 11 provided that with the bass cone 2 connected, for example glued. The calotte 11 covers the inner opening 12 the bass cone 2 completely and therefore acts as dust protection for the magnetic gap 8th ,

How to get in particular 2 recognizes is on the inside of the calotte 11 a piezo element 13 arranged. This is a thin disc that fits the inside of the calotte 11 is preferably glued. Via connection wires 14 is the piezo element 13 connectable with a tweeter circuit.

The piezo element that acts as a tweeter 13 As you can see, it sits in the center of the bass cone 2 , An approximately punctiform sound source is thus obtained for all frequencies, the location of sound generation being essentially the same for all frequencies, since the piezo element is located 13 with the bass cone 2 with moves if this due to the energization of the voice coil 6 is moved back and forth. The phase adjustment of the loudspeaker system according to the invention is particularly good as a result. On the other hand, the movement of the bass cone 2 influenced very little because of the weight of the piezo element 13 is very low.

To further improve the speaker sound can for the piezo element 13 a transformer, not shown here, can be provided, by means of which the input voltage of the piezo element is increased. The transformer coil is preferably located on the basket 1 or on the permanent magnet 9 , for example on the back. An impairment of the movement of the low-frequency membrane is excluded.

On to the voice coil 6 facing side of the piezo element 13 is also another calotte 15 provided that with the first calotte 11 is connected airtight, in particular glued. So that the piezo element 13 against pressure fluctuations in the space between the outer cap 11 and solenoid 6 be completed.

Such a speaker is inexpensive, robust and can share the acoustic advantages of a broadband combine those of a reusable system.

The must also be advantageous here low mechanical and circuit complexity are called. In addition, the vulnerability against pollution very low.

1

Loudspeaker frame

2

woofer cone

3

outer edge of 2

4

beading

5

inner edge of 2

6

voice coil

7

centering diaphragm

8th

air gap

9

permanent magnet

10

leads

11

dome

12

inner opening of 2

13

piezo element

14

leads

15

inner cap

Claims (9)

Two-way or multi-way speaker system with a tweeter element and another speaker element with a membrane as a dynamic converter such as a dome or cone speaker, in which the membrane ( 2 ) with a voice coil ( 6 ) connected in the field of a magnet ( 9 ), especially in the air gap ( 8th ) of a ring-shaped permanent magnet, characterized in that the tweeter element is designed as a piezoelectric loudspeaker, the piezo element ( 13 ) with the membrane ( 2 ) of the further loudspeaker element connected in a vibration-proof manner, in particular carried by it. Two- or multi-way speaker system according to claim 1, characterized in that the piezo element ( 13 ) in the center of the membrane ( 2 ) is arranged. Two-way or multi-way speaker system according to claim 2, characterized in that the piezo element ( 13 ) from one in the center of the membrane ( 2 ) arranged thin disc or dome ( 11 ) is worn. Two- or multi-way speaker system according to claim 3, characterized in that the normal calotte as a calotte the further speaker element is provided. Two-way or multi-way speaker system according to one of the preceding claims, characterized in that the piezo element ( 13 ) on the back of the thin disc or dome ( 11 ) is arranged. Two- or multi-way loudspeaker system according to claim 5, characterized in that a further disc or dome ( 15 ) is provided, which the piezo element ( 13 ) together with the first disc or calotte ( 11 ) encloses on all sides. Two-way or multi-way speaker system according to one of the preceding claims, characterized in that only the piezo element ( 13 ) vibration-proof with the membrane ( 2 ) connected is. Two- or multi-way speaker system according to claim 7, characterized in that the remaining components of the tweeter element on the magnet ( 9 ) of the further loudspeaker element or its basket ( 2 ) are arranged. Two-way or multi-way speaker system according to one of the preceding claims, characterized in that the piezo element ( 13 ) with the disc or dome ( 11 ) is glued.