KR20070035494A - Acoustic transducer comprising a plurality of coaxially arranged diaphragms - Google Patents

Abstract

Acoustic transducers include one or more electromagnetic motors, which are acoustically efficient with dimensions that drive one or more sets of multiple diaphragms to enable use in applications that are impossible or difficult with conventional transducers. Provide loudspeaker system. The diaphragm is driven directly, inertially or fluidly. When the diaphragm is driven by a rod passing through a hole in the diaphragm, noise may be generated by air leaking through the through hole. This noise can be reduced or eliminated by measures to reduce or eliminate air leakage.

Description

Acoustic transducer with multiple coaxial array diaphragms {ACOUSTIC TRANSDUCER COMPRISING A PLURALITY OF COAXIALLY ARRANGED DIAPHRAGMS}

TECHNICAL FIELD The present invention relates to audio systems and acoustics, and more particularly to providing improved shape factors for acoustic transducers for converting electrical signals into acoustic radiation.

The general principles of movable coil electrodynamic loudspeakers are well known. At the heart of the transducer's ability to produce sound is the concept of volumetric displacement. The volumetric displacement of a transducer with a single diaphragm is equal to the effective surface area of the diaphragm multiplied by the excursion capability of the diaphragm. The larger the volume displacement of the transducer, the greater its potential to produce sound. The need for large volume displacement is particularly noticeable at low frequencies. Typical ways to achieve greater volumetric displacements in the transducers are to increase the diaphragm surface area, increase the diaphragm deflection capability, or both.

Typical transducers used to produce significant low frequency energy include a single diaphragm with a large surface area and use a housing and a motor that provides adequate deflection of the diaphragm. This results in certain minimum dimensional requirements for the diaphragm of the loudspeaker, which in turn imposes a minimum dimensional requirement for the loudspeaker enclosure. In applications such as flat panel televisions and computer monitors, it is very difficult to use conventional transducers with good low frequency response. In these applications, the current solution is to use a separate subwoofer box to reproduce the low frequency sound, which leads to additional cost and inefficiency. The same holds true for automotive acoustic system applications where designers try to find a place to hide a subwoofer in a vehicle, which will typically be placed in the trunk or under the seat.

It is an object of the present invention to provide an acoustic transducer capable of reproducing low frequency sounds with high fidelity at high sound pressure levels, in applications that cannot be satisfactorily handled with conventional transducers.

In accordance with one aspect of the present invention, the acoustic reproduction area of an acoustic transducer is disposed over a plurality of diaphragms of shape factors more suitable for use in applications such as flat panel televisions and computer monitors and automotive acoustic systems. These multiple diaphragms can be divided into one or more groups, each diaphragm being synchronously driven by at least one motor to which all the diaphragms in the group are connected. Any motor capable of converting electrical audio signals into motion can be used to drive the diaphragms in the group. As an example, a motor consisting of a movable acoustic coil and a non-moving magnet can be used.

Certain embodiments of the acoustic transducer described herein use a housing with all diaphragms or a single motor to drive all diaphragms, or each of the two motors to drive half of the diaphragm. It is one of those used. In principle, the number of motors is very independent of the number of diaphragms. As an example, an acoustic transducer may have one group of four diaphragms driven by two motors and another group of three diaphragms driven by one motor.

Each drive motor may be connected directly or indirectly to all diaphragms that the motor drives. Indirect connection can be achieved by connecting the motor directly to the housing, the housing being sequentially connected to the diaphragm by its periphery or suspension, or by using gas or liquid fluid to couple the motor to the diaphragm. All motors in a particular acoustic transducer receive substantially the same audio signal and can be connected to each other in either serial or parallel fashion.

The material used in the construction of various embodiments of the present invention may be a material used in the construction of conventional acoustic transducers. The housing, connecting rod, and motor may be made of a material having a characteristic frequency whose resonance, vibration, or bend modes deviate from the associated audio spectrum. These components are preferably not part of the sound generating mechanism, and using materials with modes in the relevant audio spectrum results in unintentional audio artifacts. Preferably, movable elements such as diaphragms and connecting rods are made of as light material as possible to improve the efficiency of the device. By way of example, glass filled or mica filled polypropylene polyphenylene-oxide-styrene materials or carbon-fiber materials can be used.

The embodiment described herein uses a tubular shape factor with a cylindrical housing and a rounded diaphragm, however, the cross section of the housing and diaphragm need not necessarily be rounded. These may be oval, rectangular or substantially any other shape desired.

The increased complexity and additional components needed to implement the various aspects of the present invention can increase manufacturing costs and reduce the reliability of the transducer. These problems include, by way of example, that one type of module, referred to herein as a motor module, includes a magnet assembly, a coil and a diaphragm or cone, and wherein another type of module, called a diaphragm module, is a section of the housing, a diaphragm Can be mitigated or avoided by employing a modular design that includes a set of rods coupled to the suspension and diaphragm. The motor module is designed to mate with the diaphragm module and may include a set of rods that mechanically couple the motor in the motor module to the diaphragm in the adjacent diaphragm module. Alternatively, the motor module may include a diaphragm that fluidly couples to the diaphragm in the adjacent diaphragm module. The diaphragm module is also designed to mate with other diaphragm modules. Substantially any number of diaphragm modules can be assembled into a linear array of modules. The rod in each diaphragm module passes through an opening in the immediately adjacent diaphragm module and is mechanically connected to the diaphragm in the next diaphragm module. The section of each housing of the diaphragm module is adapted to mate with the section of the housing in the adjacent diaphragm module to form a chamber between the modules. The air in each chamber is acoustically isolated from the air outside the housing or acoustically associated with air outside the housing through ports, vents or other openings.

The acoustic transducer according to the invention produces a front wave or a back wave. The transducer is generally considered to be received by a housing having an opening in which the front wave is properly oriented with respect to the listener emitted through it. There are a number of well known methods for handling back waves in standard acoustic transducers, any of which may be used in the present invention. As an example, the back wave may be emitted through a transmission line introducing a delay, or it may be emitted into a large enclosure that acts as a baffle, or may be emitted directly into the ambient air. The latter method generally reduces the audio efficiency of the transducer at low frequencies.

The overall size of the acoustic transducer according to the invention depends largely on the desired audio efficiency level at low frequencies. By increasing the surface area of the individual diaphragms, increasing the deviation of the individual diaphragms, increasing the number of diaphragms, optimizing the acoustic impedance matching between the diaphragm and air, or by any combination of these factors, Higher audio efficiency can be achieved.

In accordance with one teaching of the present invention, the transducer includes a single motor that operates multiple diaphragms by using a single drive rod attached to each diaphragm. One side of each diaphragm faces the opening to the listening environment. The other side of each diaphragm is isolated from the listening environment by a baffle. The drive rod may pass through an opening in the baffle and / or diaphragm. The seal can be used to prevent or significantly reduce unintentional air leakage in any opening through which the drive rod can pass.

According to another teaching of the present invention, the transducer comprises two motors, each driving a plurality of diaphragms. The diaphragms are arranged in two groups, the diaphragms in one group are driven by one motor, and the diaphragms in the other group are driven by another motor. The groups of diaphragms are preferably driven opposite one another. The diaphragm is driven by a motor using drive rods. The drive rod may pass through an opening in the baffle and / or diaphragm. Unfortunately, air leaks through these openings, causing large amounts of intermodulation and harmonic distortion. This leakage can also significantly reduce the sound output level. Seals can be used to prevent unintentional air leakage at any opening in the diaphragm including those through which the rod can pass.

These seals may be formed from one or more pieces of lightweight foam, each piece being compressible and extensible and secured to a rod near the opening. The foam fragment compresses as the rod pushes it towards the opening and expands as the rod pulls it away from the opening. These seals may also consist of pleated fabrics, such as those used in bellows, that can expand and contract as needed. Alternatively, the drive rod may be routed in such a way that no diaphragm or baffle passes through, eliminating the need for a seal.

For these embodiments with drive rods through the diaphragm and / or baffle, it may be desirable to avoid the use of seals because the seals add cost and complexity to the embodiments. This can be achieved by designing the size of the opening in the diaphragm and / or baffle through which the drive rod passes to optimize the overall performance. These openings are referred to herein as “through openings”. Any air leakage through the through openings in the diaphragm can produce undesirable artifacts in the form of audio distortion or noise and / or a reduction in the overall volume displacement of the air. These air leakage artifacts can be reduced by increasing the resistance of the opening to air flow, or by diffusing air through the opening to produce less audible noise. The resistance can be increased, for example, by reducing the size of the opening, or by increasing the length of the path through which air travels. A number of techniques for reducing air leakage noise are described in the following paragraphs, which are used individually or in combination to achieve the desired results.

According to one technique, the resistance to air flow is increased by using thicker diaphragms to increase the length of the air travel path. This typically has the effect of increasing the mass of the diaphragm and reducing the maximum deviation for a given total transducer volume.

According to another technique, the diaphragm thickness is increased by using a "sandwich" of two diaphragms with a layer of damping material such as a viscoelastic polymer in between. The resulting synthetic diaphragm is heavily damped, which is often desirable for acoustic diaphragms because it helps to reduce sonic artifacts. The presence of the damping material allows the diaphragm to be formed of a lighter material, thereby mitigating an undesirable increase in the moving mass of the transducer.

According to another technique, the diaphragm thickness is increased by using "sandwiches" of lightweight spaced materials, such as polyurethane foams, and inextensible skin materials, such as paper. The resulting synthetic diaphragm is typically lighter and more rigid than the single diaphragm.

According to another technique, the resistance to air flow is increased by adding a cylindrical "sleeve" to the diaphragm around the through opening. The use of the sleeve has the additional effect of minimizing the increase in the mass of the diaphragm. It is desirable to shape the sleeve of the diaphragm differently on both sides. By way of example, on the outer surface of the diaphragm transmitting the front wave of the sound the listener hears, the cylindrical sleeve may be shaped into a funnel shape to reduce turbulent noise of air passing through the opening.

According to another technique, the resistance to air flow is increased by adding a sleeve of air flow resistant material around the through opening. The inner diameter of these sleeves may be small enough to allow the sleeves to fit somewhat snugly around the drive rods through the openings. The materials used for these sleeves are preferably soft and smooth to reduce undesirable friction noise when the sleeve contacts the drive rod, and possess sufficient airflow resistance to reduce the amount of air passing through the opening. do. Examples of suitable materials include silk, polyester, soft wool and other materials in combination with elastic wovens. These soft fabric sleeves are preferably mounted around shorter cylindrical sleeves made of a rigid material such as plastic or metal.

Another way to reduce air leakage noise is to seal the through opening with a material that effectively stops air flow while minimizing friction and noise. Examples of such materials include semi-fluid lubricants such as bellows and thixotropic gels made of soft and flexible fabrics. Similar effects can be achieved by using a ferromagnetic liquid between the sleeve and the rod. The ferromagnetic liquid can be held in place by a thin ring magnet attached to the diaphragm.

Another way to reduce air leakage noise is to diffuse air through the openings. One technique for achieving this is to add ductile foam at the exit point of the air movement path. In particular, a cylinder of flexible foam can be added directly around the through opening or indirectly, around a shorter cylindrical sleeve made of a rigid material such as plastic or metal. The foam is configured to extend over the rigid sleeve and may be bent inwardly to cover the opening and close contact with the drive rod. The foam may be a polyurethane mesh opening cell foam, which has the desirable property of diffusing air while reducing undesirable friction noise when in contact with the drive rod. In some applications, it may be desirable to place the foam only on the inner side of the diaphragm that transmits a back wave of sound that the listener cannot hear. This allows the user to use longer foam sleeves with smaller inner diameters. These foam sleeves can be in more intimate contact with the drive rods, so that they increase resistance to air flow in addition to diffusing air through the openings. The closer the contact of the driving rod increases the friction noise, the noise is included in the back wave and therefore less unpleasant to the listener.

Air leakage noise can be reduced through a combination of the above-described techniques, that is, by adding a sleeve to the diaphragm and increasing the thickness of the diaphragm itself.

An example of such a combination technique is to form a composite diaphragm consisting of a sandwich of two diaphragms each having a cylindrical sleeve around the through opening only on its outer surface, with a layer of damping material therebetween, Increase resistance. The reduction in air leakage noise, the amount of increase in moving mass and the amount of diaphragm damping can be customized by adjusting the thickness of the damping material layer, the thickness of the component diaphragm and the length of the sleeve.

Another example of a combination technique to reduce air leakage artifacts is to add both a flexible foam and a flexible fabric sleeve around the through opening. In particular, the flexible foam can be added around the rigid sleeve and the flexible fabric can be added around the foam, thereby combining the effect of increasing the resistance to air flow and the effect of diffusing air through the openings. do.

Another example of a combination technique for reducing leakage artifacts is the use of a tight bushing around the rod. The bushing preferably consists of an ultra low friction material such as a self-lubricating polymer. The bushing is preferably attached to the diaphragm via a flexible hermetic material to isolate the diaphragm from vibration and to allow limited movement.

The technique described above to reduce air leakage noise can be applied to any transducer using a cone or diaphragm with a hole therein. These techniques are not limited to arranging transducers using multiple diaphragms.

According to another teaching of the present invention, a transducer includes a motor that directly operates one or more structures each comprising a plurality of diaphragms suspended by a peripheral, spider or other form of suspension. The back wave of each diaphragm is acoustically isolated from the adjacent diaphragm by the baffle. The front wave of each diaphragm may pass through the opening into the listening environment. No drive rod is used, instead the diaphragm is inertia driven. This teaching can be extended to using multiple motors. Additionally, different structures can be moved in opposite directions.

According to another teaching of the invention, each drive motor is mechanically connected to a single diaphragm. This diaphragm may be coupled to another diaphragm by fluid, and the other diaphragms may be mechanically coupled to another diaphragm in sequence. In this way, one or more conventional loudspeakers can be used to indirectly drive multiple diaphragms. When pneumatic fluid coupling, such as air coupling, is used between the direct drive diaphragm and the indirect drive diaphragm, the indirect drive diaphragm behaves as if it is driven by a signal passing through a filter with low pass characteristics, and the direct drive The diaphragm acts as if it is driven by a signal with the full frequency range. In such an embodiment, the direct drive diaphragm produces most of the high frequency sound, and the indirect drive diaphragm produces most of the low frequency sound.

According to another teaching of the invention, a transducer having a housing comprises a plurality of diaphragm modules each having a section of the housing, a diaphragm suspended from the section of the housing and a set of one or more rods coupled to the diaphragm. . The section of the housing for each diaphragm module has a first surface and an opposing second surface. The first surface of the section of the housing in one diaphragm module mates with the second surface of the section of the housing of the other diaphragm module in such a way that a chamber is formed between each diaphragm of the adjacent module. The section of the housing for the module has a port, vent or other type of opening that allows acoustically coupling air inside the chamber to air outside the chamber. The rod in each diaphragm module passes through an opening in the immediately adjacent diaphragm module and is mechanically coupled to the diaphragm in the next diaphragm module. In one embodiment, the set of rods in one module protrudes from one surface of the diaphragm, and the opposing surface of the diaphragm has a fixture adapted to receive and mate the rods of the module following the adjacent module. In another embodiment, the first set of rods protrude from one surface of each diaphragm and the second set of rods protrude from an opposing surface of the diaphragm. The ends of the two sets of rods are adapted to mate with each other.

According to another teaching of the invention, the diaphragm module described above does not have a rod coupled to the diaphragm. Each diaphragm module consists of a section of the housing and a diaphragm suspended from the section of the housing. After the central section of the transducer is assembled from a plurality of these diaphragm modules, the rod is inserted and attached to the appropriate diaphragm by a joining process such as adhesive bonding or sonic welding, and one or more motor modules are attached to the central section of the transducer. Attached to the end.

In any of the foregoing embodiments, the sleeve may be added around the through hole, or the diaphragm may be a composite diaphragm consisting of two diaphragms with a layer of damping material interposed therebetween. The sandwich diaphragm may also include a cylindrical sleeve on one or both of its surfaces to reduce undesirable air leakage noise.

In any of the embodiments described above, the diaphragm suspension need not have the same properties or orientations at all. As an example, in embodiments where the diaphragm is driven directly, it may be desirable to use a more rigid suspension in the vicinity of the motor to minimize movement in a direction other than in the direction of the actuating drive rod. In addition, by orienting the suspension portion of the diaphragm operated by a single motor so that some of the suspension portion is directed in the opposite direction with respect to the other suspension portion, the asymmetry characteristic of the suspension portion can be canceled or reduced, thereby reducing the distortion characteristic of the transducer have.

Various features of the present invention and preferred embodiments thereof will be better understood with reference to the following description and accompanying drawings. The following description and content of the drawings are presented by way of example only and should not be understood as limiting the scope of the invention.

1 is a schematic representation of an embodiment of the present invention using a baffle, a single internal drive rod and a single motor.

2 is a schematic diagram of an embodiment of the present invention that uses multiple internal drive rods and two motors and no baffles;

3 is a schematic representation of an embodiment of the present invention using a baffle, multiple external drive rods, and a single motor.

4 is a schematic diagram of an embodiment of the present invention that uses multiple external drive rods and two motors and no baffles;

5 is a schematic representation of an embodiment of the present invention that uses a baffle and a single motor and does not use a drive rod.

6A-6C are schematic views of a diaphragm module that can be used to manufacture an acoustic transducer according to the present invention.

7 is a schematic perspective view of an embodiment of an acoustic transducer according to the present invention which is mechanically coupled using a diaphragm module similar to those illustrated in FIGS. 6A-6C.

8 is a schematic cross-sectional view of the transducer shown in FIG. 7.

9 is a schematic perspective view of an embodiment of an acoustic transducer according to the present invention that is fluidly coupled using a module similar to those illustrated in FIGS. 6A-6C.

10 is a schematic cross-sectional view of the transducer shown in FIG. 9.

11A-11C are schematic views of a composite diaphragm consisting of two diaphragms with a damping material layer interposed therebetween.

12A-12C are schematic views of a diaphragm module having a cylindrical sleeve around the through opening.

13A-13C are schematic views of a composite diaphragm composed of two diaphragms each having a cylindrical sleeve around a through opening only on its outer surface with a damping material layer interposed therebetween;

14A and 14B are schematic views of a diaphragm having a cylindrical sleeve around the through opening and a flexible fabric sleeve around the cylindrical sleeve.

15A and 15B are schematic views of a diaphragm having a cylindrical sleeve around the through opening and a flexible foam sleeve around the cylindrical sleeve.

16A and 16B are schematic views of a diaphragm having a cylindrical sleeve around the through opening, a flexible foam sleeve around the cylindrical sleeve, and a flexible fabric sleeve around the foam sleeve.

17A and 17B are schematic views of a diaphragm having a cylindrical cylindrical sleeve around a through opening on the outer surface of the diaphragm and a cylindrical sleeve around the through opening with a flexible foam sleeve around the cylindrical sleeve on the inner surface.

18A and 18B are schematic views of a diaphragm with soft bellows around the through opening only on its inner surface;

19A and 19B are schematic views of a diaphragm having a cylindrical sleeve around the through opening, a ring magnet around the sleeve only on its inner surface, and a ferromagnetic liquid between the sleeve and the drive rod.

20A and 20B are schematic views of a diaphragm having a cylindrical sleeve around the through opening only on its outer surface, with a ring magnet around the through opening only on its inner surface, and having a ferromagnetic liquid between the magnet and the drive rod;

21A and 21B are schematic views of a diaphragm with a semi-fluid lubricant covering the through openings.

22A is a schematic representation of a diaphragm module housing section with ribs.

22B is a schematic perspective view of an acoustic transducer including a module housing section with ribs.

23A-23C are schematic views of domed diaphragms with integral rods and sleeves.

FIG. 24A is a schematic perspective view of a modularly constructed transducer including a domed diaphragm with a flexible foam sleeve and a modular housing section with ribs. FIG.

24B is a schematic cross-sectional view of a modularly configured transducer with a flexible foam sleeve and a domed diaphragm.

A. Direct Drive

1 shows an embodiment of the invention in which the electromagnetic motor comprises a magnet 1010 and a voice coil 1020 and a mechanical coupling 1030 coupled to the drive rod 1040 is mounted to the voice coil. . The drive rod is attached to the diaphragm 1050, each angle of the diaphragm being sequentially attached to the housing 1060 by each suspension 1070. The audio signal is applied to the voice coil and the acoustic wave from one side of the diaphragm can be radiated through the opening 1080 into the listening environment. Acoustic waves from the other side of the diaphragm can be radiated from the set of other openings 1085. Unintentional air leakage is substantially prevented by seal 1100 and baffle 1090. If necessary, one or more bushings are used in the motor to prevent undesirable voice coil movement. Alternatively, drive rod 1040 may pass through all or some of diaphragm 1050 without using a seal. The size of the space between the diaphragm and the rod can be optimized to minimize air leakage while minimizing friction between the rod and the diaphragm.

FIG. 2 shows one embodiment of the invention in which the electromagnetic motor comprises a magnet 2010 and a voice coil 2020 and a mechanical coupling 2030 coupled to the drive rod 2040 is mounted to the voice coil. . The drive rod 2040 is attached to the diaphragm 2050, each of which is sequentially attached to the housing 2060 by each suspension 2070. The suspension portions 2070 need not all have the same characteristics. As an example, it may be desirable to use a more rigid suspension in the vicinity of the voice coil to minimize movement of the voice coil in a direction other than the direction of the actuating drive rod. The stiffness of the suspension 2070 can be controlled by manipulating the suspension shape or material. Also, by orienting the suspension of the diaphragm operated by a single motor to direct in the opposite direction, the distortion characteristic of the transducer can be reduced. In this particular embodiment, the drive rod 2040 passes through one, but not all, of the diaphragms 2150 via an opening that is sealed by the seal 2180. The other motor includes a voice coil 2120 and a magnet 2110 with a mechanical coupling 2130 coupled to the drive rod 2140. The driving rod 2140 is attached to the diaphragm 2150, and each of the diaphragms is sequentially attached to the housing 2060 by each suspending portion 2170. In this particular embodiment, the drive rod 2140 passes through one, but not all, of the diaphragms 2050 via an opening that is sealed by the seal 2180. Voice coils 2020 and 2120 are connected such that each diaphragm operates in the opposite direction to the next diaphragm. When an audio signal is applied to the transducer, acoustic waves from the front of the diaphragm can radiate through the opening 2090 into the listening environment. Leakage between the front wave and the back wave is substantially prevented or reduced by the seal in the diaphragm. The back wave may radiate through the opening 2190. Alternatively, the drive rods 2040, 2140 may pass through some or all of the diaphragms 2050, 2150 without using a seal. The space between the diaphragm and the rod can be optimized to minimize air leakage while minimizing friction between the diaphragm and the rod. After considering the variation of the component due to manufacturing tolerances of this embodiment of the present invention, the net momentum change of the mechanical component is zero or substantially zero, thus the transducer housing 2060 is substantially free of vibration.

3 shows an embodiment of the invention in which the electromagnetic motor comprises a magnet 3010 and a voice coil 3020, in which the voice coil is mounted on a mechanical coupling 3030 to which two drive rods 3040 are coupled. Shows. The drive rod 3040 is attached to the diaphragm 3050, which in turn is attached to the housing 3060 by a suspension 3070. When an audio signal is applied to the transducer, acoustic waves from one side of the diaphragm can radiate through the opening 3080 into the listening environment. Acoustic waves from the other side of the diaphragm may radiate through the opening 3180. Unintentional air leakage between individual chambers is substantially reduced or prevented by baffle 3090.

4 shows an embodiment of the invention in which the electromagnetic motor comprises a magnet 4010 and a voice coil 4020, and the voice coil is mounted to a mechanical coupling 4030 coupled to the drive rod 4040. . The drive rod 4040 is attached to the diaphragm 4050, which in turn is attached to the housing 4060 by a suspension 4070. The different motors have a magnet 4080 and a voice coil 4090, which has a mechanical coupling 4100 coupled to the drive rod 4110. The driving rod 4110 is attached to the diaphragm 4120, and the diaphragm is attached to the housing 4060 by the suspending portion 4130 in sequence. The voice coil is connected such that each diaphragm operates opposite the diaphragm adjacent thereto. When an audio signal is applied to the transducer, acoustic waves from the front of the diaphragm may radiate through the opening 4160 into the listening environment. Acoustic waves from the back of the diaphragm may radiate through the opening 4180. The net momentum change of the mechanical part of this embodiment of the present invention is zero or substantially zero after taking into account the variation of the part due to manufacturing tolerances, so that the transducer housing is substantially free of vibration.

The main difference between the embodiments illustrated in FIGS. 2 and 4 is the configuration of each rod that drives half of the diaphragm in the transducer. Another embodiment of the invention uses two groups of rods, each group comprising a plurality of rods. Each rod group is connected to half of the diaphragm and passes through the other half of the diaphragm. As an example, the embodiment illustrated in FIGS. 7 to 10 uses six rods that are symmetrically distributed in a circular pattern around the center of the diaphragm, with adjacent rods separated from each other by an angle of 60 degrees. The six rods are divided into two groups of three rods, and the rods of these two groups are interlaced with respect to each other. This means that the three rods in each group are symmetrically distributed in a circular pattern equidistant from the center of the diaphragm, with adjacent rods in the group separated from each other by an angle of 120 degrees. Each group of three rods is attached to one half of the diaphragm and, via a sealed or non-sealed opening, of the diaphragm in a form similar to that described above for rods 2040 and 2140 and illustrated in FIG. Pass the other half. In this arrangement, each diaphragm is operated symmetrically by three rods that form a unique two-dimensional plane in three-dimensional space, while the three attachment points to the diaphragm are distributed symmetrically. If the rods and diaphragms are properly aligned so that all rods are parallel to each other, all diaphragms are parallel to each other, and all rods are perpendicular to the surface of all diaphragms, then the diaphragms receive symmetrically distributed normal forces, which They tend to move in the desired longitudinal direction without causing any unsuitable vibration modes that can lead to undesirable sonic artifacts.

Another embodiment of the invention uses one rod and one tube that are concentric. The outer diameter of the rods is smaller than the inner diameter of the tubes, so when they are mounted concentrically, the rods do not contact the tubes. The rod is attached to a first set of diaphragms consisting of half of all diaphragms of the transducer and passes through a second set of diaphragms consisting of the other half of the diaphragm. The tube is attached to the second set of diaphragms and passes through one or more diaphragms in the first set of diaphragms. The rod passes through the diaphragm of the second set of diaphragms by the fact that it is completely housed inside the tube. The tube consists of a plurality of sections connected to each other and one or more connecting rods through the openings in the first set of diaphragms. Preferably, the three connecting rods are symmetrically distributed over the circumference of the tube section.

In any of the direct drive implementations described herein, the diaphragm suspensions need not all have the same physical properties or orientations. For example, it may be desirable to use a more rigid suspension in the vicinity of the motor to minimize movement in a direction other than the direction of the actuating drive rod. The stiffness of the suspension can be controlled by manipulating the suspension shape or material. Also, by orienting the suspension portion of the diaphragm operated by a single motor so that some of the suspension portions are oriented in the opposite direction with respect to the other suspension portions, the asymmetrical characteristics of the suspension portion can be canceled or reduced. In a conventional embodiment, the suspension has an asymmetric response to the force generated by the drive motor. Typically, the asymmetric response introduces distortion into the resulting acoustic wave produced by the moving diaphragm. By reversing the orientation of some of the suspensions, the asymmetry of the overall suspension response can be reduced, thereby reducing the distortion of the resulting acoustic wave.

B. Indirect Drive

FIG. 5 illustrates one embodiment of the invention in which the electromagnetic motor includes a magnet 5010 and a voice coil 5020, and a mechanical coupling 5030 coupled to the housing 5040 is mounted to the voice coil. The housing is connected to the diaphragm by suspension 5060. Individual chambers are created by baffle 5070. Acoustic waves from the front of the diaphragm may radiate into the listening environment through the opening 5080. Acoustic waves from the back of the diaphragm may radiate through the opening 5180. Offset between the front and rear of the diaphragm is substantially reduced or prevented by the baffle 5070. At a frequency well below the resonance of the diaphragm / suspension assembly, the diaphragm moves in the very same phase as the housing and produces virtually no sound. At frequencies very above the resonance of the diaphragm / suspension assembly, the diaphragm is almost motionless, and the relative motion between the housing and the diaphragm produces sound. As a result, the resonant frequency of the diaphragm / suspension assembly can be selected to achieve the desired frequency response of the transistor.

The suspensions need not all have the same physical properties or orientations. As described above, by changing the orientation of the suspension, the asymmetry of the suspension can be canceled or reduced to reduce the distortion characteristics of the transducer.

C. Modular Configuration

6A-6C, 7 and 8 illustrate another embodiment of the present invention that enables an acoustic transducer assembled into a module. Such modular implementations may enable greater manufacturability, flexibility, and performance compared to non-modular implementations.

6A-6C illustrate one implementation of a diaphragm module. 6A shows a front view of the diaphragm module, FIG. 6B shows a rear view of the same diaphragm module, and FIG. 6C shows a cross-sectional view of the same diaphragm module. The diaphragm module includes a diaphragm 6050 attached to the housing section 6060 via a suspension 6070. Housing section 6060 includes an opening 6190 on the front side and another opening 6290 on the rear side. The housing section 6060 has a protrusion 6162 on the front side and a protrusion 6262 on the rear side, and a corresponding slot 6164 on the front side and a corresponding slot 6264 on the rear side, respectively. The diaphragm module also includes a section of three rods 6040, each with a protrusion 6061 on the front side and a mating opening 6062 on the rear side. The rod 6040 may be integrated with the diaphragm 6050 to improve structural integrity. Such diaphragm / rod components can be produced, for example, using materials such as glass filled or mica filled polypropylene-polyphenylene-oxide-styrene in the molding process. Diaphragm 6050 has three openings 6080 to allow rods of adjacent diaphragms to pass through diaphragm 6050. If necessary, the diaphragm module may include suspensions having different physical properties or different orientations as described above.

When two adjacent diaphragm modules are assembled together to form an embodiment of one transducer, the front side of the first diaphragm is attached to the front side of the second diaphragm. The rod 6040 of the first diaphragm passes through the hole 6080 of the second diaphragm. The protrusion 6162 of each of the two diaphragm modules slides into the slot 6164 of the other module and can be joined via operations such as adhesive bonding or sonic welding. The first opening 6190 of the first and second diaphragms combine to create an opening to allow the forward acoustic wave to be transferred to the ambient air. An assembly comprising two diaphragm modules combined in this manner can be assembled with a third diaphragm module whose rear side is attached to the rear side of the second diaphragm module. Protrusions 6162 of each of the second and third diaphragm modules can slide into slots 6244 of the other module and be joined via operations such as adhesive bonding or sonic welding. The rod protrusion 6061 of the first diaphragm slides into the rod opening 6062 of the third diaphragm and may be joined via an operation such as adhesive bonding or sonic welding. The rear openings 6280 of the second and third diaphragms are combined to create an opening for allowing the rear acoustic wave to be vented to ambient air.

In a preferred embodiment, the housing section 6060 of the diaphragm module is made of a material having sufficient strength and stiffness to provide a stable support structure for the diaphragm such that the transducer does not produce significant artifacts. Although the housing section is made of a rigid plastic material such as glass filled or mica filled polypropylene-polyphenylene-oxide-styrene, the stiffness of the resulting transducer may not be sufficient. In this case, the rigidity of the modular assembly can be improved by adding ribs to the outer wall of the housing section. 22A illustrates a housing section 22060 having an integral flange 22160 and ribs 22260 on its outer surface. Adjacent housing sections may be attached to each other with an adhesive and a screw through opening 22460 for additional stiffness. The resulting modular transducer assembly 22000 is shown in FIG. 22B.

The assembly procedure described above can be continued to add additional diaphragm modules to form a linear array of diaphragm modules having substantially any desired length. A second type of module, referred to herein as a motor module, includes a mechanical coupling designed to be attached to the rear side of the diaphragm module.

The linear array of diaphragm modules can be assembled with one or more motor modules to produce a complete transducer. By way of example, FIGS. 7 and 8 illustrate an embodiment of a transducer according to the invention consisting of two motor modules 7100 and twelve diaphragm modules. Each motor module 7100 includes a magnet assembly 7110, a coil 7120, and a mechanical coupling 7130, wherein the coupling connects the motor to the first diaphragm and from there through the rod 6040. Connect to the diaphragm. The number of diaphragm modules that can be connected together in this form can be selected to produce transducers of any length and of any volume displacement, and the motor provided provides for operating the load provided by the selected number of diaphragm modules. Have enough power.

D. Fluid Drives FIGS. 9 and 10 show that the motor module 9100 is similar to a motor used in a conventional transducer, and includes a magnet assembly 9110, a coil 9120, and a cone 9130. Another embodiment is illustrated. The cone portion 9130 is fluidly connected to the first diaphragm 9140 through the fluid contained in the sealed chamber 9150. Diaphragm 9140 is mechanically connected to residual diaphragm 6050 via rod 6040. The back wave from the direct drive cone 9130 may contribute to the front wave of the diaphragm 6050. If the fluid used in the sealed chamber 9150 between the direct drive cone 9130 and the indirect drive diaphragm 6050 is a gas such as air, the fluid drive includes a low pass filter. In this case, the direct drive cone 9130 is driven to generate significant acoustic energy over its entire frequency range, and the indirect drive diaphragm 6050 is driven to produce significant acoustic energy only at lower frequencies. Can be.

E. Reduced Air Leakage Noise

11A-11C, 12A-12C and 13A-C illustrate three different techniques that can be used in various combinations to reduce undesirable air leakage noise through the through openings of the diaphragm.

11A-11C illustrate one technique using synthetic diaphragm 1150. FIG. 11A shows an exploded view of a composite diaphragm 1150 with two component diaphragms 11150 and 11250 and a damping material layer 11350 therebetween. Damping material layer 11350 may be attached to component diaphragms 11150 and 11250 using a process such as adhesive bonding molding. FIG. 11B shows a rear view and FIG. 11C shows a cross sectional view of the composite diaphragm 1150.

12A-12C illustrate another technique of using diaphragm 1250 having a sleeve around its through opening. FIG. 12A shows a rear view, FIG. 12B shows a front view, and FIG. 12C shows a cross-sectional view of diaphragm 1250 having a sleeve 12450 around its through opening.

13A-13C illustrate another technique of using a composite diaphragm 1350 having a sleeve around its through opening. FIG. 13A shows an exploded view of a composite diaphragm 1350 with two component diaphragms 13150 and 13250 and a damping material layer 13350 therebetween. The damping material layer 13350 may be attached to the composite diaphragms 13150 and 13250 using a process such as adhesive bonding or molding. Each of the two component diaphragms 13150 and 13250 has a sleeve 13450 around its corresponding through opening. A sleeve is formed on the outer surface of each composite diaphragm, which is a side facing away from damping material 13350. 13B shows a cross-sectional view of composite diaphragm 1350.

14A and 14B illustrate another technique of using a diaphragm 1350 with a rigid sleeve and a soft fabric sleeve around its through opening. FIG. 14A shows a side view, and FIG. 14B shows a cross-sectional view of the resulting assembly, which includes a diaphragm 1450 having a rigid cylindrical sleeve 14450 around each of its through openings on both sides of the diaphragm 1450. ). The soft fabric sleeve 14550 attaches to the exterior of the rigid sleeve 14450 and extends past them, and is in close contact with the rod 1404 where the diaphragm 1450 slides through the through opening.

15A and 15B illustrate another technique using a diaphragm 15050 having a rigid sleeve and a flexible foam sleeve around the through opening. FIG. 15A is a side view and FIG. 15B shows a cross-sectional view of the resulting assembly, which includes a diaphragm 15050 having a rigid cylindrical sleeve 15450 around each of the through openings on both sides of the diaphragm 15050. do. The flexible foam sleeve 15650 attaches to the outside of the rigid sleeve 15450 and preferably contacts the rod 15040 that slides through the through opening of the diaphragm 15050 beyond them.

16A and 16B illustrate another technique of using a rigid sleeve, a flexible foam sleeve and a flexible fabric sleeve around the through opening. FIG. 16A shows a side view and FIG. 16B illustrates a cross-sectional view of the resulting subassembly, which includes a diaphragm having a rigid cylindrical sleeve 16450 around each of its through openings on both sides of the diaphragm 1160. 16050). The flexible foam sleeve 16650 is attached to the outside of the rigid sleeve 16450. The flexible fabric sleeve 16550 attaches to the outside of the flexible foam sleeve 16650, extends beyond them, and makes nearly contact with the rod 1160 40 which slides through the through opening of the diaphragm 165050.

17A and 17B illustrate another technique using a diaphragm 1750 having a rigid sleeve and a flexible foam sleeve around the through opening. 17A shows a side view, and FIG. 17B shows a cross-sectional view of the resulting subassembly, which includes a diaphragm 17050 having a rigid cylindrical sleeve 17450 around each of its through openings on both sides of the diaphragm 1750. ). The flexible foam sleeve 17650 is attached to the outside of the rigid sleeve 17450 only on the inner surface of the diaphragm 1750, which is in close contact with the rod 1740 to further reduce resistance to air flow. Sleeve 17450 has a puncture shape on the outer surface of diaphragm 1750 to provide a significant reduction in air leakage noise.

18A and 18B illustrate a technique for preventing air leakage using a diaphragm 1850 with a flexible bellows around its through opening. FIG. 18A shows a side view, and FIG. 18B shows a cross-sectional view of the resulting subassembly, which includes a diaphragm 1850 having a flexible bellows 18750 on its inner surface. One side of bellows 18750 is connected to diaphragm 1850 around each of its through openings. The other side of bellows 18750 is connected to rod 18040. Flexible bellows 18750 extends and contracts as diaphragm 1850 and rod 1840 move relative to each other.

19A and 19B illustrate another technique for preventing air leakage using a diaphragm 19050 having a rigid sleeve, a ring magnet and a ferromagnetic liquid. 19A shows a side view, and FIG. 19B shows a cross-sectional view of the resulting subassembly, which includes a diaphragm having a rigid cylindrical sleeve 19450 around each of its through openings on both sides of the diaphragm 19050. 19050). Ring magnets 19950 are attached to the outside of the rigid sleeve 19450 on the inner surface of the diaphragm 19050, which are preferably polarized in the vertical direction for improved efficiency. The ferromagnetic liquid 19960 is disposed between the sleeve 19450 and the rod 19040, and is held in place by the magnetic force of the ring magnet 19950 when the rod 19040 moves relative to the diaphragm 19050.

20A and 20B illustrate another technique for preventing air leakage using a diaphragm 20050 with a rigid sleeve, a ring magnet and a ferromagnetic liquid. FIG. 20A shows a side view and FIG. 20B shows a cross-sectional view of the resulting subassembly, the subassembly having a diaphragm 20050 having a rigid cylindrical sleeve 20450 around its through opening on the outer surface of the diaphragm. Include. Ring magnets 20950 are attached around diaphragm 20050 on the inner surface of diaphragm 20050, and they are preferably polarized in the vertical direction for improved efficiency. The ferromagnetic liquid 20960 is disposed between the ring magnet 20950 and the rod 20040, and is held in place by the magnetic force of the ring magnet 20950 when the rod 20040 moves relative to the diaphragm 20050.

21A and 21B illustrate another technique for preventing air leakage using diaphragm 21050 with semi-fluid lubricant such as thixotropic gel. FIG. 21A is a side view and FIG. 21B shows a cross-sectional view of the resulting subassembly, the subassembly comprising a diaphragm 21050 having a semi-fluid lubricant 21980 covering its through openings on both sides of the diaphragm. do. Lubricant 21980 seals the opening such that rod 21040 slides through the opening but substantially eliminates air flow through the running opening.

The thickness of the diaphragm and the length of the sleeve can be adjusted such that the total length of the air path through the through opening is as short as 2 mm, or as long as 25 mm or more. The air path length can be set according to the needs of the application and the desired audio quality level. Path lengths of about 15 mm are good for many applications.

The figure illustrates an embodiment of an acoustic transducer with a flat or planar diaphragm. The shape of the diaphragm is not important in principle. Other shapes may be used, such as cones or domes.

23A-23C illustrate a domed diaphragm 23050 having an integral rod 23040 and a sleeve 23450. FIG. 23A shows a front view, FIG. 23B shows a rear view, and FIG. 23C shows a cross-sectional view of diaphragm 23050. Because of the dome shape of the diaphragm, flat landings are added to accommodate air leakage reduction components and to improve stiffness. The flat landing 23455 surrounding the sleeve 23450 attaches a component to reduce air leakage noise, such as, for example, the flexible foam sleeve 17650 shown in FIG. 17 or the ring magnet 19950 shown in FIG. 19. Used to Flat landings 23045 surrounding rod 23040 are added to make diaphragm 23050 more suitable for high volume manufacturing methods such as injection molding. A reinforcement plate 23047 is also added for structural support of the joint between the rod 23040 and the landing portion 23045. The flat landings 23045 and 23455 are pushed toward the front side of the diaphragm 23050 to increase the spacing between neighboring diaphragms, which increases the maximum allowable deviation of the entire transducer.

FIG. 24A shows a domed diaphragm having an integral flange 24160 and ribs 24260 on its outer surface and a sleeve and an integral rod 2240 whose back sides are surrounded by a flexible foam sleeve 24650. A perspective view of a modularly assembled transducer 24000 with 24050 is shown, and FIG. 24B shows a cross sectional view thereof.

Claims (54)

In acoustic transducers, housing; A plurality of diaphragms separated into two or more groups, the diaphragms of at least one of the diaphragms being connected to each other by a rod at least partially passing through the opening of the diaphragm, the diaphragms having the opening passing through the opening A plurality of diaphragms comprising a component which blocks or diffuses air; And One or more motors operative in response to an electrical signal; The diaphragms of each group are acoustic transducers driven by each motor to which all diaphragms in the group are coupled. 2. The diaphragm module of claim 1, wherein the diaphragm module is a plurality of diaphragm modules coupled to each other, each diaphragm module comprising a section of the housing and one or more diaphragms coupled to the sections of the housing; An acoustic transducer comprising one or more motors, each formed of one or more motor modules coupled to one or more diaphragm modules. The acoustic transducer of claim 2, wherein each diaphragm module includes one or more rods coupled to the one or more diaphragms. 4. The opening of the diaphragm of the third diaphragm module according to claim 3, wherein at least one rod of the first diaphragm module is connected to the diaphragm of the second diaphragm module and is interposed between the first and second diaphragm modules. An acoustic transducer that passes through. The diaphragm module of claim 4, wherein at least one rod of each diaphragm module protrudes from one surface of the diaphragm, and an opposing face of the diaphragm receives and ends an end of at least one rod of the module coupled to each diaphragm module. An acoustic transducer having one or more fixtures adapted to mate. The method of claim 4, wherein the first set of one or more rods protrude from one surface of each diaphragm, the second set of one or more rods protrude from opposite surfaces of each diaphragm, and the ends of the two sets of rods Acoustic transducers applied to match each other. The acoustic transducer of claim 1, wherein the component includes a seal formed around the opening. The method of claim 7, wherein the seal is: At least one piece of compressible and expandable lightweight foam, each disposed in each opening; One or more bellows, each retractable and inflatable, disposed in each opening; A ferromagnetic liquid disposed in each opening held in place by one or more magnets attachable to each diaphragm; or A lubricant disposed in each opening; Acoustic transducer comprising a. The method of claim 7, wherein the seal is: At least one piece of lightweight foam, each of which adheres to a rod near the opening, the at least one piece of lightweight foam each foam compresses as the rod pushes it towards the opening, and expands as the rod pulls him away from the opening; One or more bellows, each secured to a rod near the opening and capable of inflating and contracting, one or more bellows compressing as the rod pushes it towards the opening and expanding when the rod pulls it away from the opening; or A lubricant disposed on the rod near the opening; Acoustic transducer comprising a. The acoustic transducer of claim 1, wherein the component comprises a diaphragm feature wherein a sandwich of three layers of material is disposed around the opening and the intermediate layer is a damping material such as a viscoelastic polymer. 2. The component of claim 1 wherein the component comprises a feature of the diaphragm wherein a sandwich of three layers of material is disposed around the opening, the outer layer is a material that resists elongation, and the middle layer is a low density material such as a polyurethane foam. Stick transducer. The acoustic transducer of claim 1, wherein the component comprises a sleeve around the opening. 13. The acoustic transducer of claim 12, wherein the sleeve is shaped differently on each side of the diaphragm. 14. The acoustic transducer of claim 13, wherein the cylindrical sleeve is shaped into a puncture on one side of the diaphragm. 13. The acoustic transducer of claim 12, wherein the inner diameter of the sleeve is small enough for the sleeve to fit snugly around the rod. The acoustic transducer of claim 15, wherein the sleeve comprises a first material that is soft and slippery to reduce friction with the rod. The acoustic transducer of claim 16, wherein the sleeve also includes a second material on the diaphragm that is rigid (inflexible), the first material mounted on the second material. 13. The acoustic transducer of claim 12, wherein the sleeve has a magnet and a ferromagnetic liquid is disposed between the sleeve and the rod passing through the opening. The acoustic transducer of claim 1, wherein the component comprises a foam disposed around the opening. 20. The acoustic transducer of claim 19, wherein the component comprises a sleeve mounted on the diaphragm about the opening and the foam is mounted on the sleeve. 21. The acoustic transducer of claim 20, wherein the component comprises a soft fabric mounted on a foam. 20. The acoustic transducer of claim 19, wherein the foam is mounted on the side of the diaphragm opposite the side that transmits the sound the listener hears. 20. The acoustic transducer of claim 19, wherein the foam is mounted on the side of the diaphragm that transmits the sound the listener hears. 20. The acoustic transducer of claim 19, wherein the foam is mounted on two sides of the diaphragm. The acoustic transducer of claim 1, wherein the component comprises a bushing disposed around the ring in the vicinity of the opening. 27. The acoustic transducer of claim 25, wherein the component comprises a flexible material disposed about the opening while attached to the bushing. In acoustic transducers, housing; A plurality of diaphragms separated into one or more groups, the diaphragms of the at least one diaphragm group comprising: diaphragms connected to each other by rods routed out of the housing such that they do not pass through the diaphragm; And One or more motors in combination with a housing operating in response to an electrical signal; The diaphragm of each group is driven by each motor to which all the diaphragms in the group are coupled, and at least one motor has a coupling with a direct mechanical connection to the diaphragm it is driving. 28. The apparatus of claim 27, further comprising: a plurality of diaphragm modules coupled to each other, each diaphragm module comprising a section of the housing and at least one diaphragm coupled to the section of the housing; And One or more motor modules coupled to one or more diaphragm modules, wherein the acoustic transducer is formed of one or more motor modules each including one or more motors. 29. The diaphragm module of claim 28, wherein each diaphragm module includes one or more rods coupled to the one or more diaphragms, wherein one or more rods of the first diaphragm module are interposed between the first and second diaphragm modules. An acoustic transducer routed around the third diaphragm and connected to the diaphragm of the second diaphragm module. 27. The diaphragm of claim 1, 27 or 7-26, comprising two diaphragm groups and two motors, each motor actuating each group of diaphragms A group of acoustic transducers are driven in opposite directions. 27. The method of any one of claims 1, 27 or 7-26, wherein two or more diaphragms are each suspended from the housing by a suspension, and the suspensions for the two or more diaphragms have different physical properties or orientations. Acoustic Transducer 32. The diaphragm of claim 31 wherein at least two diaphragms in a group are suspended from the housing by suspensions, the diaphragms in the groups having suspensions having different stiffnesses, wherein the suspension stiffnesses drive the diaphragms in the group. Higher acoustic transducer for diaphragm closer to motor. 33. The diaphragm of claim 32, wherein the two or more diaphragms are each suspended from the housing by a suspending portion, wherein some of the group of diaphragms have a suspending portion having a first orientation, and other diaphragms within the group are in the first orientation. An acoustic transducer having a suspension with an opposing second orientation. 33. The diaphragm of claim 31, wherein the two or more diaphragms are each suspended from the housing by a suspending portion, and some of the group of diaphragms have a suspending portion having a first orientation, and the other diaphragms in the group are in the first orientation. An acoustic transducer having a suspension with an opposing second orientation. The acoustic transducer of claim 4, wherein the component includes a sleeve around the opening. 36. The device of claim 12 or 35, wherein at least one diaphragm in the plurality of diaphragms has a domed or conical surface and has one or more integral rods, each surrounded by a flat landing, wherein the flat landing is a dome. An acoustic transducer that is concave below a contour or cone surface. 37. The acoustic transducer of claim 36, comprising one or more ribs or one or more flanges on an outer surface of the housing extending across the plurality of diaphragms along the length of the transducer. 36. The device of claim 12 or 35, wherein at least one diaphragm in the plurality of diaphragms has a domed or conical surface and has one or more sleeves, each surrounded by a flat landing, the flat landing being dome shaped. Or an acoustic transducer that is concave below the conical surface. 39. The acoustic transducer of claim 38, comprising one or more ribs or one or more flanges on an outer surface of the housing extending across the plurality of diaphragms along the length of the transducer. The acoustic transducer of claim 1 or 2, comprising one or more ribs on an outer surface of the housing extending across the plurality of diaphragms along the length of the transducer. The acoustic transducer of claim 1 or 2, comprising one or more flanges on an outer surface of the housing extending across the plurality of diaphragms along the length of the transducer. The acoustic transducer of claim 1 or 2, comprising one or more ribs or one or more flanges on an outer surface of the housing, extending across the plurality of diaphragms along the length of the transducer. In acoustic transducers, housing; A plurality of diaphragms separated into one or more groups and suspended from the housing; And One or more motors in combination with the housing, operative in response to the electrical signal; Each group of diaphragms is driven by each motor to which all the diaphragms in the group are coupled, and at least one motor has an indirect coupling having a non-direct mechanical connection to the diaphragm driven by that motor. Producer. 44. The acoustic transducer of claim 43, wherein the indirect coupling includes each motor connected to the housing. 44. The acoustic transducer of claim 43, wherein the indirect coupling is a gas or liquid fluid that couples the motor to the diaphragm. 46. The acoustic transducer of claim 45, wherein each motor is coupled to the first diaphragm and the fluid couples the first diaphragm to a second diaphragm in the group of diaphragms. 47. The acoustic transducer of claim 46, wherein the fluid is received in a sealed chamber between the first diaphragm and the second diaphragm. 44. The apparatus of claim 43, further comprising: a plurality of diaphragm modules coupled to each other, each diaphragm module comprising a housing and one or more diaphragms coupled to the housing; One or more motor modules coupled to one or more diaphragm modules, wherein the acoustic transducer is formed of a motor module including one or more motors. 49. The acoustic transducer of claim 48, wherein each diaphragm module includes one or more rods coupled to the one or more diaphragms. The acoustic transducer of claim 49, wherein at least some of the rods pass through openings in the diaphragm. 50. The system of claim 49, wherein one or more rods of the first diaphragm module are connected to the diaphragms of the second diaphragm module and routed to circumscribe a third diaphragm module interposed between the first and second diaphragms. Acoustic transducer. 48. An accord according to any one of claims 43 to 47, comprising two groups of diaphragms and two motors, each motor actuating each group of diaphragms, the group of diaphragms being driven opposite to each other. Stick transducer. 48. The acoustic transducer of any one of claims 43 to 47, wherein at least two diaphragms are each suspended from the housing by suspending portions, and the suspending portions for the at least two diaphragms have different physical properties or orientations. 54. The diaphragm of claim 53, wherein the at least two diaphragms are each suspended from the housing by a suspension, and some of the diaphragms in a group have a suspension having a first orientation, and the other diaphragms in the group are in a first orientation. An acoustic transducer having a suspension having a second orientation opposite to.

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