DE3036149A1 - Electroacoustic transducer assembly - has two symmetrically positioned oscillators joined to ribbed membranes - Google Patents

Abstract

The membrane elements (2), rectangular in shape and stiffened lengthwise by grooves, are each joined at one of their ends (3) to a transducer oscillator respectively (1,1a). The free edges of the thin membrane (5,5a) are abutted to one another to form an obtuse angle at the centre, not greater than 160 degrees. The surfaces of the centre edges (5,5a) where the two membranes meet, are rounded off and joined by a flexible, elastic fixing. The rounding off of the edges allows them to move smoothly on one another when oscillations of large amplitude are produced. The driver system (1,1a) consists of magnetic pole pieces and magnetic bars joined to the membranes by a 'U' shaped silicon which also carries the current conductors. When both transducers (1,1a) produce oscillations, a movement of the membranes due to the sound pressure occurs, whose resultant direction is always vertical to the axis of symmetry (7) of the two oscillators (1,1a).

Description

The invention relates to an electroacoustic transducer according to

the genre of claims 1 and 2.

A larger membrane area with a central vibration drive It is well known that transmitting the same phase position to all points includes extensive Compromise solutions with one, especially if a comprehensive audio frequency spectrum is broadcast shall be.

To stabilize the Membranen by multiple folding or by Putting two equal cones together with their bases to swing them as a whole to let, however, is limited with the increasing inertia and can also only incomplete with regard to the problem of partial oscillations be solved.

Typical versions are the DPS 598 145 and DPS 548 807.

The other characteristics of such membranes are not clear Radiation characteristic, since the effective membrane components are out of phase and compensate for each other Opposite membrane parts and the bending moments that occur.

Efforts were therefore made to divide the membrane area into several individual membranes to be divided up and equipped with separate vibration generators or via rods, pole pulls using holding threads, support elements from a central drive system to drive off, as recently made known by DAS 26 49 771.

As a result, apart from one not inconsiderable expense these systems are less suitable for all-round radiation and only limited Obey frequency sections, thereby assigning them to corresponding crossovers will.

So are electroacoustic transducers with bendable non-developable ones Membrane body known, so among other things also with spherical and olive-shaped membrane bodies, see under GB-PS 312 666 and DE-OS 26 o7 858, which outwardly describes the subject matter of the invention see similar, but not the features underlying the inventive concept exhibit In the case of the items listed, which in general are called flexural oscillators, the force vectors are at the equatorial area of the closed menstrual body directed against each other.

The same also applies to one side of the membrane body acting vibration generator known from the DE-AS 27 o9 374, where the unilateral Mounting of the membrane body as a static counterforce also on the equatorial area occurs compensating and the division of the frequency range into different Membrane sizes cannot be eliminated.

In addition, the bending forces that are stored and released again require additional damping means to counteract non-linear distortions.

In connection with this, US Patent 3,424,873 should be noted here, in which a closed steep cone divided into three frequency ranges radiates radially in flexural waves and for effective bass reproduction in conventional Kind of axially scilwingen on a resonance box.

On the other hand, the invention is based on the object of a coherent Sound image without frequency subdivision and only from one, from at least two of the same To let individual elements of the existing membrane emit, the previously indicated Defects are largely eliminated.

The solution to this problem arises from the features of the characteristic Part of claims 1 and 2.

A membrane lobe made up of several individual elements, their membrane elements are connected to one another by folding is known. The invention shows This feature too, depending on the design, differs significantly from the previous one known principles.

The peculiarity of the invention is based essentially on the division into two parts the membrane, which can be interpreted as a kink membrane and of which each membrane part rigid, driven by a separate vibration generator.

Since the vibrations over the membrane elements in their longitudinal direction only sound pressure-generating membrane deflections can occur the interaction of both membrane elements at their opposing contact edges, namely at the kink where the Diaphragm speed is greatest.

The membrane elements are at an obtuse angle to one another and are rounded at their edges, whereby a mutual rolling during the oscillation process, especially large amplitudes, without the occurrence of bending forces.

The embodiment according to the invention therefore requires the deflection in a sound pressure generating membrane deflection no use of polygons, Retaining threads and membrane bends or other membrane folds.

In contrast to conventional, well-known electrodynamic converters, where the transmitted vibration direction is essentially in the direction of the diaphragm deflections occurs and transverse waves and propagation delays are not neglected can, the embodiment according to the invention has the advantage that the stability the membrane elements in their longitudinal direction unwanted transverse and longitudinal waves and thus elimination of runtime delays, since the vibrating component being transmitted also lies in the longitudinal direction of the membrane elements.

Inferring from this, high frequencies are also in the range of the largest Membrane fast radiated intensified and crossovers or the Division of the membrane system into different frequency ranges is excluded. In addition, the mutually oscillating membrane elements have a counter-coupling effect.

The invention enables both flat membranes on baffles, as well as all-round radiating membranes, the latter being a larger one Missing angle in the drive direction is conceded, since the usual advantage here Annular gap magnets known in loudspeaker construction can be used and closed Housing shapes and baffles are out of the question.

Flat membranes require special devices on which the invention is based for propulsion Magnetic constructions that have an incorrect angle of the transmitted vibration component in Exclude longitudinal direction on the membrane element.

With regard to the required stability and the membrane materials used, the membrane elements are generally limited in length to 150 to 200 mm, however, the width can be freely selected.

In the case of large radiation areas, we recommend extending the width vertically to relocate. If necessary, limited .iembranssysteme can also be used in a large number can be arranged side by side at any angles and vertically, depending on required radiation characteristics.

So if all-round radiation is desired, several, however at least three such buckling diaphragm systems arranged in a circle, their long sides with each other in the known way by folding, softer, if possible, anechoic material, are connected and thus form two pyramid-shaped membrane cones lying next to one another. The, for example, on pressure in their axial directions, a spreading of their membrane elements experience and thus a radial deflection at the equatorial area.

Depending on the voice coil diameter, the membrane elements must a trapezoidal blank can be given.

The voice coil is connected directly to the membrane body and at smaller voice coils via a connector. But the energy component compels per surface element, also with regard to the longitudinal stability and the low frequency range, that the voice coil must not fall below a certain minimum diameter.

The amount of energy transferred is with a straight conductor favorable, because the angle of error in the drive oscillation direction is equal to zero on the entire membrane surface up to the effect of both vibration components on the Contact edges of the membrane elements. In a further embodiment of the invention, the driving current conductor is not disconnected, but immediately on the membrane element or attached within the same.

The question of negative feedback can easily be solved according to the invention. So will in the area of the greatest speed, i.e. in the resulting oscillation direction, namely on the opposing membrane edges, also a dynamic receiver attached, whose voltages can be used for negative feedback in the amplifier.

The starting material for the membrane elements is expediently hard Corrugated aluminum sheet in combination with softer materials, which creates the membrane surface has fundamental internal damping with sufficient longitudinal stability.

The invention is illustrated below with reference to some in the drawing Embodiments detailed and explained. They show: Fig. 1 schematically the active components of the two membrane elements with dynamic vibration generators Wig. FIG. 2 shows a perspective sectional partial view of one formed according to FIG. 1 Oscillating system Fig. 3 is a front view of a surface radiator Fig. 4 schematically a magnet arrangement for membrane elements with applied current conductors and their Holder in the magnetic field Fig. 5 shows a membrane element with an applied conductor for surface radiators Fig. 6 two trapezoidal membrane elements connected by folds for diaphragm bodies radiating all around FIG. 7 a view of a diaphragm body radiating all around Membrane body made of several trapezoidal cut membrane elements with two dynamic annular gap magnets and connecting cones for adaptation to smaller ones Voice coils (1 cone shown in section).

The surface radiator Fig. 3 consists of the frame (14) and the fold seals (15) and the kink diaphragm (13) with the drive systems (1 and 1a).

The drive systems consist of the magnetic poles (8) and the magnetic bars (9) composed. The conductors are located on the U-shaped bent part (lo) that is held by the suspension (11) and with the membrane element (13) connected at (lo).

The frame is advantageously designed as a load-bearing structure and If the length is very long, it receives multiple transverse stiffeners. For fastening the Drive systems are to choose obvious angle constructions.

If the converter is not to be used as a dipole beam, this is the Frame to be closed on one side and boxes closed by the usual methods to execute.

Fig. 5 shows an embodiment where the conductor (17) directly the membrane element (18) is applied.

Although this has the disadvantage of a somewhat more complex magnet construction, However, as can easily be seen from FIG. 4, the pivot point position (16) is still over relocated the end of the membrane element so that the drive oscillation direction always remains in the longitudinal direction of the membrane element and also oscillates in antiphase Membrane parts cannot occur.

A major advantage, however, is that at the pivot point position (16) A simple adjustment can be made to maintain symmetry of the two opposing vibration components is necessary.

Fig. 7 shows an all-round radiator made of several trapezoidal Membrane elements (29) and, as can be seen from Fig. 6, by folds (19) on their Long sides connected to each other. The folds are made of elastic anechoic material manufactured.

The two completely identically formed cones are reinforced on theirs Edges (20) in Fig. 6 connected with elastic adhesive (30) Fig. 7 and as shown in Fig. 2 at (12) is also clearly evident.

The adaptation to smaller voice coils takes place via the cones (28) in Fig. 7 on which the adjusting disks (26), which are corrugated and made of plastic existing, are also appropriate.

If the voice coil size is sufficient, the membrane cones are directly with connected to the voice coils.

The cage-like housing is symmetrical and is supported by the Cover plates (22) and (23) with the five connecting columns (21) in Fig. 7 are formed.

The two annular gap magnets (24) are connected to the plates (23).

The axially adjustable pins (25) lead through the magnets (24) to the adjusting washers (26) and are used in particular to regulate the preload of the two cone diaphragms and to adjust the symmetry of each other axially directed vibration components of both voice coil drives.

In summary, the invention is a broadband system, which in its structure offers great possibilities for variation in the radiation characteristics allows. Because the electroacoustic transducers neither crossovers nor a division the membrane body requires different frequency ranges, the invention continues thus setting new standards in electroacoustics for the first time.

Claims (5)

Claims: Electroacoustic converter for sound reproduction with two symmetrically arranged electrodynamic vibration generators oscillating against each other, between which at least two non-flexing membrane elements in the same Line of symmetry to the vibration generators are, thereby g e k e n n z e i c h n e t that the vibrations of an electrodynamic vibration generator (1) an essentially non-flexible, rigid one stiffened by longitudinal grooves, preferably square membrane element (2) from one edge (3) in the longitudinal direction (4) are transferred and that the opposite edge (5) is identical to a second one Membrane element (2a) at an obtuse angle "alpha" of not greater than 160 degrees is counter-supported, which is also opposite in the longitudinal direction (4a) the Vibrations of a second vibration generator (la) are transmitted to the first is arranged symmetrically opposite, so that only from the interaction Both vibration components cause a deflection of the membrane elements that generates sound pressure results, the resulting oscillation direction (6) at the opposing surface edges of the membrane elements (5 and 5a) always perpendicular to the symmetry axis (7) of the two Vibration generator (1 and la) is available when these vibrate against each other to the same degree are operated and that the opposing surface edges (5 and 5a) reinforce (durSh t20) and are rounded so that when they vibrate, especially with large amplitudes, can roll against each other and there; these edges by elastic glue to the Membrane sides of the angle included by them "Alpha" are held. 2. Electroacoustic transducer according to claim: 1, thereby g e k It is noted that the conductor (17) at the end on the membrane element, Fig. 5, or is attached within the same and -that the pivot point position (16) -outside of the membrane element is and there the adjustment can be made, the to maintain the symmetry of the two opposing vibration components necessary is. 3. Electroacoustic transducer according to claim 1, thereby g e k It is noted that the membrane elements of FIG. 6 are essentially elongated designed trapezoidal and there several, but at least three such under claim 1 listed buckling diaphragms are arranged in a circle, the diaphragm elements Fig. 6 with their conical sides by elastic folds (19) in particular anechoic material are connected and so two identical pyramid-shaped reciprocating Form diaphragm cone Fig. 7, which is preferably made by vibration generators with annular gap magnets (24) are operated. 4. Electroacoustic transducer according to one of claims 1 to 3, characterized it is not indicated that the wavy adjusting disk (26) is within of the diaphragm body and the preload regulation through the adjustable pin (25) of the conical diaphragms and the adjustment of the symmetry of the axially directed against each other Vibration components of both voice coil drives made possible. 5. Electroacoustic transducer according to one of claims 1 and 3, characterized It is not noted that for adaptation to smaller voice coil diameters (27) there are corresponding connecting cones (28) on the diaphragm cone.