JPH0761189B2 - Electro-acoustic transducer device - Google Patents

Description

Detailed Description of the Invention a. FIELD OF THE INVENTION The present invention is an omnidirectional improvement on a conventional electroacoustic transducer which is capable of accurately simulating the spatial and frequency and dynamic characteristics of a live performance throughout the listening room, especially in a stereo system. The present invention relates to an electroacoustic transducer device.

B. Conventional technology and problems Throughout the history of electric sound reproduction, the loudspeaker is the weakest point in the sound reproduction connection despite the great development efforts for it, and is the last area where significant improvements are possible. Is generally accepted. Efforts have been focused on the design of electroacoustic transducers that form speaker diaphragm drive members or drivers, as well as the design of baffles or enclosures that house these members. Perhaps the most focused attention has been on focusing efforts to improve performance, resulting in the development of highly sophisticated transducers of the electrostatic, ribbon, ceramic, magnaranar and cone dynamic radiator types. There is.

However, the inherent characteristic of all these cone-type or flat-type diaphram radiators is that they exhibit out-of-phase back-radiation that is dipolar and therefore requires isolation or manipulation to prevent sound cancellation. On the other hand, the rest of the forward radiation exhibits a directional pattern of response which gradually becomes smaller as the vibration region becomes larger with respect to the wavelength of the sound being reproduced, with increasing frequency. Such a phenomenon is somewhat reduced in a multiplex type device in which a low-frequency driver is used to reproduce low frequencies and a small-diameter speaker is used to reproduce intermediate and high frequency regions, but it is not completely eliminated. Not done. The dispersion in this case varies from 360 ° at very low frequencies, and sound waves are diffracted at high frequencies around 30 ° or less than 30 °, depending on the perimeter of the enclosure, the crossover frequency and the size of the driver. It fluctuates up and down.

Therefore, it can be seen that a box-type or flat-type baffle speaker having a driver member mounted on the front surface cannot obtain a pattern of a directional characteristic as a function of frequency. Since the divergence angle is not constant, the total acoustic output of the speaker varies with similar frequencies even if the on-axis response is perfectly flat.

In the early 1930s, true reproduction of the live sound field in a typical listening room would not be possible unless speakers were developed that were both axially flat and had flat total acoustic output versus frequency. The number of experts in the field of sound reproduction admitted to increase. Developing such a speaker is necessary to develop an accurate room echo field.

Since it is obviously impossible to obtain a conventional loudspeaker with limited but constant dispersion in frequency, a logical alternative is to have an omnidirectional structure.

The theoretically ideal but practically unattainable solution lies in the pulsating spheres that form the perfect point source of sound, but in reality,
This is not possible because the sphere must be small for the wavelength of the sound being produced, and therefore at the same time small at high frequencies and large at low frequencies to be able to move and hear the air sufficiently.

Heretofore, it was wasteful for a person skilled in the art to devise a special driver member or enclosure using a standard cone-type driver that precisely matches the propagation characteristics of the pulsating sphere.

One attempt used was to reflect sound away from vertically aligned cone-type drivers and away from reflectors such as spheres, cones or pyramids to obtain a 360 ° lateral dispersion. Next, the number sequence is described.

Evans U.S. Pat.No. 3,0 granted Dec. 22, 1936
No. 65,367 discloses an embodiment of a single-cone loudspeaker that radiates upwards into a sphere, upwards into a pyramid and further downwards into a pyramid.

Hegel's German Patent No. 2,3, announced on December 5, 1974
In No. 25,603, a low-pitched speaker and a high-pitched speaker are placed on a common vertical line, and a large cone is provided above the high-pitched speaker. It is disclosed.

Williams U.S. Patent, No. 29, April 1980
No. 4,200,170 has a speaker radiating downward into the pyramid, a stacked structure in which one radiates upward and one radiates downward into the pyramid, and three speakers each radiate downward into the pyramid. Is disclosed.

Analysis of the structures of these Evans, Hegel and Williams shows that they have the following general drawbacks.

1. When a speaker driver emits sound into the pyramid, the lateral dispersion uniformity is distorted by diffraction from the edges of the pyramid.

2. A standing wave has a relatively constant sag between the two surfaces in the space between the driver cone and the reflecting object, especially in the case of pyramids or cones with similar included angles and when using a sphere. Slightly attributed to the development. Thus, in these structures, unwanted resonances occur at frequencies where the sag represents an integer multiple of half a wavelength of the frequency being reproduced.

3. When the reflector is used, the interference pattern develops, and the additional distance that the sound radiating away from the reflector has to travel between the speaker and the reflector causes the person listening after the direct sound from the speaker driver. As it arrives at the ear, there is a varying response to degradation of the steady state signal and transients.

4. Vertical dispersion is not improved for driver orthogonal patterns when using pyramidal or cone reflectors, only slightly and selectively at spherical reflector frequencies. Therefore, in the case of the above structure, a flat acoustic output due to frequency cannot be achieved due to the effect of the directional pattern of fluctuation of vertical dispersion with frequency.

5. In the case of Williams and Hegel, there is no physical means to achieve the time alignment between the output of the bass and treble speakers. Since both speakers are aligned on the same vertical axis, the transient acoustic output from the treble speaker arrives at the listener's ear before the same sound from the bass speaker due to the faster response time of the treble speaker.

Dickey, U.S. Patent No. 4, November 2, 1982,
No. 357,490 discloses a speaker that radiates upward into an ellipsoidal body having a large number of high-pitched loudspeakers mounted on its surface.
This form also has the drawback of not being able to achieve mainly omnidirectional dispersion in the lateral direction, as in the previous examples of cone-type drivers that reflect sound away from the sphere. Elliptical mounted treble speakers typically extend the high frequency response of cone-type drivers and provide widely diffused lateral and vertical acoustic dispersion patterns, while treble loudspeakers distributed over an elliptical surface are necessary. Intense reinforcement and cancellation effects for persistent sound in the spectrum at different distances from the listener and the reflective surface of the room, and thus the distance difference of the driver represents an integer multiple of half a wavelength of the frequency being reproduced ( Roving) as well as multiple arrival times for transient sounds. For example, in the case of 10 cm intervals,
At 1725 Hertz, the lowest frequency zero and 29 ms transient response time difference are shown.

Berlant U.S. Pat.No. 4,348,549 has a bass speaker with a conical plug that reflects downwards towards the floor and a compression driver mounted upwards on a novel radial horn. Bi-directional device systems have been proposed which form a horizontal dispersion. In this case, the first problem is seen especially in the limited vertical dispersion from the bass speaker, and the second problem is due to the relatively large distance between the bass speaker and the treble speaker output ports, especially in the near field. It is difficult to achieve smooth mid-range response,
Third, it is difficult to form an appropriate crossover frequency response overlap between a reasonably sized high frequency horn and a large sized low frequency speaker when the low frequency speaker faces a floor with varying and unknown sound absorption. can give.

Fell's German Patent No. 2701080 dated January 12, 1977
No. 5,837,242 discloses an inverted truncated pyramid having large dome-shaped loudspeakers mounted on opposite vertices. Also shown is a three-way embodiment having a dome speaker in an upward position radiating to the plate and a bass, mid-range and high frequency dome speaker radiating upwards to a flat or shaped plate. .

The usefulness of this method is limited by the availability of the wide range of large dome speakers required. In the case of one large dome or two domes facing each other, the high frequency response can only be expected to that normally obtained with bass speakers of the same size. In the case of the multi-speaker system, standing wave resonance is exhibited in the frequency range in which the distance between the plates and the plate diameter dimension indicate an integral multiple of a half wavelength of the frequency being reproduced. Diffraction from the edge of the plate can also be expected.
It is unknown how the vertical dispersion of the speaker will improve.

Gefvert U.S. Pat. No. 3,816,672 describes a special bass / midrange speaker pointing downwards into a long barrel and upwards treble into a hyperboloidal reflector for horizontal dispersion. A three-way device system is disclosed, which is composed of a speaker for sound and another speaker for high frequency range which forms a vertical dispersion upwardly above it, all of which are aligned on the same vertical axis.

This Geffbert style is very complicated and difficult to make especially attractive for home use. This requires a mechanically integrated structure and, in the preferred embodiment, a specially designed bass / midrange speaker with a diameter of only about 15 cm. It is doubtful that a speaker of this size can produce a natural level of low frequency sound.
Further, there is no means for adjusting the time between the bass / midrange speaker and the treble speaker.

U.S. Pat. No. 3,500,953 by UL Lahti
The publication discloses a structure in which a high-frequency cone-type speaker that radiates upwards to an adjustable dish reflector and a bass speaker that faces downwards toward the floor are provided in a spherical or cylindrical enclosure. Has been done. Analysis shows that this design produces frequencies that are independent of radial omnidirectionality, but due to floor effects on downward-emitting bass loudspeakers and a large sag between bass and treble loudspeakers, Like the patent, the verticality varies significantly with frequency. Furthermore, the disadvantages 2 and 3 mentioned in the criticisms of Evans, Hegel and Williams for the standing wave and the delayed response also apply here.

Other quasi-omnidirectional styles are commercially available, typically using up to 28 speakers per speaker stereo pair and emitting sound in various forms from a cabinet. In each of these design methods, intense roving and impact distortion occur, resulting in 1
No single flat acoustic output vs. frequency criterion is met.

C. The present invention relates to a new form of omni-directional electroacoustic transducer device capable of reproducing the acoustic field of the original performance with greater precision than was previously possible, especially in stereo devices. Is. This is made possible by the complete spectral response and the spatial reproduction characteristic with a great improvement which allows the realization of natural sound levels in the reproduction of large musical ensembles in synchronization with a wide dynamic range.

This performance characteristic includes a normal treble speaker and a bass / intermediate speaker in a new enclosure, which results in a flat axial direction over the entire wavelength range and a 360 ° lateral flat sound output. It is achieved by obtaining a vertical dispersion of ± 60 ° with respect to direction without roving or other anomalies.

The present invention includes a base enclosure having a side and a bottom, the top being formed of a truncated pyramid, and oriented to emit sound outwardly attached to the face of the truncated pyramid. A low-range / intermediate-range speaker, an acoustic dispersion sphere supported above the low-range / intermediate speaker by a vertical member mounted on the base enclosure, and the acoustic dispersion sphere by the vertical member Including a partial sphere coaxially supported above the sphere, and a high-range speaker provided on at least one of the acoustic dispersion sphere and the partial sphere, the high-range speaker including the acoustic dispersion. An electroacoustic transducer device is provided that is oriented to emit sound into a space formed between a sphere and the partial sphere.

In this way, a single drive element is provided by a novel device in which another sphere is provided with a treble speaker for driving an intermediate air space facing one spherical surface of two closely facing spherical surfaces. A radiation index projector is formed that deploys a coherent magnifying acoustic field of 360 ° laterally and 120 ° vertically. The frequency band is from 2 KHz or less to 20 KHz or more. Increasing the efficiency of the treble speaker increased by about 4 times due to the air load of the treble speaker, which was an unprecedented increase in the maximum sound output level obtained from an ordinary dome dome speaker. .

The superstructure support for the sphere and treble loudspeaker module includes a mechanical device that allows the sphere to be moved from an axial position to a rear position, while maintaining a fixed treble speaker in the dome space. Provided, thereby providing a continuous user adjustment of the treble loudspeaker lateral radiation pattern of the sound spread from omnidirectional to the front hemisphere.

As a result of mounting four 16.5 cm bass / intermediate loudspeakers in a quadrant circle, the evenly fixed fingerless directional radiation pattern is maintained through the bass and lower midrange, and is also precise. Due to the beneficial effect of the overlapping presence of the truncated pyramid and the sphere and loudspeaker,
Such a fingerless directional radiation pattern is extended to above the upper mid-range 2 KHz.

The base enclosure is placed on legs or castors 5-8 cm above the floor to allow the use of downward floor-loaded duct ports or auxiliary radiant baffles (ARB) on the bottom panel. This modality results in effective propagation of very low frequency energy from the bottom of the base enclosure.

The base enclosure preferably comprises non-parallel sides and internal supports to minimize internal standing waves and consequently acoustic radiation generated from the outer surface of the base enclosure.

The effective center of radiation from the bass / midrange speaker is sufficiently in front of the treble speaker, and the response time is adjusted more slowly, so the output of the treble speaker and the bass / intermediate range are adjusted. The time alignment with the output of the range speaker is accurately maintained for the shock response.

An internal electrical crossover network of conventional design usually operates at 2KHz, directing high audible frequencies to the treble speaker and low frequencies to the bass / midrange speaker.

D. Embodiment In FIG. 1, the inclination of the side surface of the base enclosure 1 is usually 1 /
6 or 6 cm in height, the surface is inclined so as to deviate to 1 cm inclusive.

The structures according to the invention can be implemented in various sizes, usually within the range of 2: 1 or 3: 1. The criterion is determined by acoustic parameters that are appropriately related to each other. This point will be described in more detail later.

A typical size of the base enclosure 1 forming the base pyramid is a width of the bottom 10 of 54 cm, a top width of 40 cm and a height of 70 cm.
The base pyramid is vertically adjusted and supported above the floor by four legs 2, each of which has a height of about 6 cm.
Is. Apart from this, this leg may be a caster.

Wooden support rods 8 and 9 are provided to impart acoustic rigidity to the sides of the base pyramid.

The base 10 of the base pyramid is closed by a rigid surface, which is horizontally inclined at a 1/6 angle to the truncated top surface. An acoustic port, preferably three duct-shaped ports 3, is provided. These ports 3 are hollow cylinders that extend into the internal volume of the base pyramid and are usually 9 cm in diameter and 15 cm long.

The embodiment of FIG. 1 is provided with four bass / intermediate range loudspeakers 12 mounted on each side of a 45 ° truncated pyramid 15 forming the top of the base enclosure 1. These loudspeakers 12 are electrically interconnected, forming the same conical region as a single large bass speaker for equivalent low frequency reproduction, with the advantages of improved upper mid-range response and increased divergence angle. . Each of these four loudspeakers 12 has a diameter of about 16.5 cm and may be of the long spacing type P17RCY, the manufacturer of which is SEAS Fabrikker Als from Nole. The acoustic range is about 30Hz to 5,000Hz.

The top edge of the base enclosure 1 blocks the diffraction of sound at the rounded edges with a radius of about 2 cm.

Physical support for the treble loudspeaker 5 mounted on the acoustic dispersion sphere 4 and the partial sphere 14 above it is provided by four vertical members of minimum cross-sectional area, such as metal (or wood) angle members 6. ing. Each angle member 6 is provided with a quarter-circle insert member to form a rounded inner surface to prevent sound diffraction. Of course, instead of the angle member 6, a round metal tube may be used to prevent diffraction.

The angle member 6 is a partial sphere from the bottom 10 of the base enclosure 1.
It extends upwards towards the four arms 7 at the top of the structure supporting 14. Along the way, two curved horizontal members 13 are provided on the side surface of the base enclosure 1 to form a pair of adjacent angle members 6.
Respectively, and forms a device for supporting the acoustic dispersion sphere 4 at both ends of its horizontal diameter.

Preferably, the support of the acoustic dispersion sphere 4 has two female screws, both ends of which are threaded so as to receive a holding screw which penetrates a hole in the acoustic dispersion sphere and slides in the pore 16 of the horizontal member 13. Hollow rods 17 and 17a are provided. As a result, the position of the acoustic dispersion sphere 4 can be adjusted back and forth, while maintaining a constant sag between the acoustic dispersion sphere 4 and the radiation dome of the high-frequency speaker 5.

Supported by four radial arms 7, usually radius 15.2
A downward treble speaker 5 is attached to the bottom of a 5 cm partial sphere 14. The high-range speaker 5 has a 28 mm dome radiator, an outer diameter of about 11 cm, and a vertical cylinder length of 3 cm. The wavelength range is 1KHz, and the soft dome type D28A from Dynaudio of Denmark.
The one of F is good.

The sag between the dome of the high-range speaker 5 and the acoustic dispersion sphere 4 is preferably the closest one that can be tolerated by manufacturing error, and is within 1 mm. The acoustic dispersion sphere 4 has a diameter of about 15.25c.
At m, it is located about 1 cm above the top surface of the truncated pyramid 15.

Normally, an internal electrical crossover network with a conventional design method that operates at 2 KHz is used to direct high audible frequencies to high-range speakers and low frequencies to low-range / intermediate range speakers. Attenuation slopes of 12 dB per octave are preferred over both high and low pass sections. The crossover frequency may be chosen higher or lower than typical values to optimize performance depending on the particular transducer device.

E. Action Regarding the mounting of bass / intermediate range speakers, the purpose is to achieve a lateral dispersion of 360 ° and a vertical dispersion of ± 60 ° with an absolute minimum sag between the acoustic centers of each speaker. To achieve. Due to the proximity of the sag, there is sufficient phase shift to initiate the development of audible constructive and destructive reinforcement of the sound as a function of frequency and listener position with the time difference of the first arrival sound from each speaker. Before being introduced, it is determined how low / mid speakers can operate at high frequencies.

As in the preferred embodiment, by mounting 16.5 cm speakers on each of the four sides of the 45 ° pyramid, an approximately even lateral dispersion of 360 ° and ± 60 ° near the ± 90 ° crossover at low frequencies. A reduced vertical dispersion is inherently obtained. The difference in the sag of the center of the sound changes from 0 to 10 cm depending on the angular position of the listener with respect to the speaker. This neglects the necessary non-trivial effect of rear-firing speakers.

Vertical or horizontal mounting of speakers is not preferred. Because the difference between the vertical arrangement is 0 to 18 cm, and the difference between the horizontal arrangement is 18 cm to 25 cm, which is an undesirable stab of the standing wave between the speaker and the acoustic dispersion sphere, and the direct sound from the speaker. This is because there is an additional phase error due to the difference in the arrival time of the sound of the sound and the sound reflected from the acoustic dispersion sphere.

In the worst case, with a 10 cm difference in acoustic center, the listener's position in the preferred embodiment exhibits an arrival time difference of 290 microseconds, which theoretically produces a zero output at 1720 Hz. However, in practice, this is due to the narrowness of the dispersion angle of the speaker in this frequency range, the overlap of the output of the high-frequency speaker, and the diffusion effect of the upper acoustic dispersion sphere. A slight drop is brought about in the range of 1300Hz with responsiveness.

Since the low-range / midrange speaker does not radiate directly to the acoustic dispersion sphere due to its 45 ° baffle equipment, the effect of the acoustic dispersion sphere on these speakers is relatively small. Therefore, the acoustic dispersion sphere mainly serves to improve the maximum angle of downward vertical dispersion of the loudspeaker, isolate the mutual effect of the opposite loudspeakers, and eliminate the effect on the high frequency loudspeaker.

The use of a smaller and closer speaker (a) or a low crossover frequency (b) reduces the arrival time difference between the bass and midrange speakers, but the adoption of (a) replaces the low frequency maximum output. Level and range reduction, (b)
In this case, the difficulty of implementation due to the lack of an appropriate high-range speaker and the suspicion of crossover in the critical 200Hz to 2000Hz intermediate range can be cited.

The use of a 16.5 cm bass / intermediate speaker and a 2 KHz crossover frequency is considered optimal, but does not preclude other forms of use.

For mounting the high-frequency range speaker in the transducer device of the present invention, a new structural form is used in which the dome of the sound-generating high-frequency range speaker is used to drive the gap between the facing spherical surfaces aligned in the vertical direction.

This results in an exponential mode radiation projector that allows omnidirectional, high frequency sound propagation from a single dome treble speaker.

This structure acts almost as a single point source of acoustics, and it is uniform 360 ° horizontal and ± 60 at frequencies over 2KHz and over 20KHz.
A vertical distribution is formed, without the anomalies associated with multiple speakers or wide area transducers such as roving, picket fence response or multiple early arrivals of a single transient.

Typically, the treble loudspeaker is mounted on the upper acoustic dispersive sphere 4 or partial sphere 14 and is preferably located below it, facing downward toward a closely spaced, fully acoustic dispersive sphere of the same radius. It Alternatively, the treble loudspeaker may be mounted upwards on the lower acoustic dispersion sphere with the same effect.

The sag between the dome of the high-range speaker and the acoustic dispersion sphere or partial sphere must be on the order of 1 mm or as close as manufacturing tolerance allows. The reason is firstly to achieve maximum air loading due to maximum efficiency with maximum bandwidth, and secondly the direct treble speaker output and the reflected output from the lower or upper sphere. The reason for this is to minimize the difference in the passage length between the lanes and make it meaningless. Thirdly, the audible limit is exceeded as close as possible between the face plate of the high frequency speaker and one of the spheres. It is possible to raise the lowest standing wave frequency that can be supported. In the case of the preferred embodiment, the sag between the face plate of the treble speaker and either sphere is 19.9 KH.
It is achieved by being determined to be 8.62 mm, which represents the half wavelength of the sound at z.

The resulting treble speaker efficiency is typically 5-6 decibels greater than that obtained with ordinary panel equipment,
Four times the maximum sound output is obtained. For greater power operation, opposing treble loudspeakers driven in phase can be mounted on adjacent surfaces of the acoustic dispersion sphere and the partial sphere. It should be understood that a partial sphere can be replaced with a full sphere. These spheres are usually hollow and made of glass or a corresponding ultra-hard material such as ceramic or glassy plastic. Soft wood and similar soft materials are not good. An arbitrary light emitting member such as a light bulb 20 made of translucent glass or the like is housed in the sphere and illuminated by the sphere. A sound control type lamp can also be used.

The support structure of the acoustic dispersion sphere and the treble speaker is adjusted manually from the normal axial alignment position of the acoustic dispersion sphere to the treble speaker rearward alignment position, while the treble speaker Designed to maintain a constant sag between the dome and the acoustic dispersion sphere, which allows the user to continuously adjust the lateral radiation pattern of the treble speaker from omnidirectional to forward hemispherical. There is.

In order to place the loudspeakers away from the walls of the room, as is often the case in large rooms, a uniform spherical pattern on both the horizontal and vertical planes is preferred, and the acoustic dispersion spheres are used for high and low range loudspeakers. It is secured by being coaxially positioned on both of the mid-range speakers. In high-fidelity sound reproduction, however, a stereophonic (“stereo”) signal source is provided and two transducer devices according to the invention are used at a distance of a few meters from one another.

When the transducer device has to be placed exactly on the wall of the room, it may be necessary to optimize the wall reflectivity or the radiation pattern for best acoustic coverage and minimal acoustic feedback in acoustic reinforcement applications. It is preferred to limit the directional pattern to a hemisphere or free space in front of the wall.

This is 5.4 cm behind the acoustic dispersion sphere 4 in this embodiment.
It is achieved by moving a distance of. In this position, the vertical axis of the treble speaker is relative to the acoustic dispersion sphere.
It strikes the surface at an angle of 45 °. The rest of the acoustic dispersion sphere above the 45 ° point is an obstacle, and the sound from the treble speaker cannot radiate to the rear wall.

The upper audible frequency in the low range speaker range such as the crossover frequency of 1,000 to 3,000 Hz is given a certain directivity depending on the position of the acoustic dispersion sphere like the high range speaker frequency. However, 100H
Low audio frequencies, such as z and below, are omnidirectional, but this does not affect the capabilities of the transducer device of the present invention.

The structure according to the invention allows a great improvement in acoustic fidelity by maintaining the uniformity of amplitude and phase over the entire range of the sound produced by the transducer device in all directions. As an example, if the sound contains audible frequencies emitted by both the bass midrange speaker and the treble loudspeaker, these frequencies must arrive at the listener's ear at the same instant in time, so Otherwise, blurring of the acoustic image will occur. The inertia of the larger moving device of the bass / midrange speaker is greater than the inertia of the smaller moving device of the treble speaker. Thus, when a step function waveform such as tap dance is applied to both speakers, the sound is first emitted by the treble speaker and then by the bass / intermediate speaker. The spacing between these sounds is only a fraction of a thousandth of a second, but the effect is discernible. This effect can be eliminated by arranging the treble range speaker as far as the bass / intermediate range speaker away from the listener so as to achieve correct "time adjustment" as in this configuration.

In the case of the preferred embodiment, the bass / intermediate range speaker is placed on the speaker baffle consisting of the truncated pyramid 15 so that the speaker is oriented directly about 10 cm in front of the acoustic center of the treble range speaker. An acoustic emission center for the speaker is obtained. This causes a delay of about 290 microseconds in the output of the treble speaker relative to the output of the bass / intermediate speaker, which causes a large delay and looseness in the output of the bass / intermediate speaker. The correct rise time is corrected, and accurate time alignment of both outputs can be obtained.

Another major advance in sound reproduction fidelity provided by the present invention is the ability of the device to emit spatially and spectrally accurate sound field outputs. This can be proved quantitatively by the fact that the device can be said to exhibit the same frequency response in all its radiating directions and therefore a flat total acoustic output or power responsive frequency relationship.

This property is important because the transducer device is almost always operated in the room, whether in the living room of the home or in the playing field. In such a situation, the sound heard by the listener is the sound directly emitted from the transducer device and the sound reflected from the wall, ceiling or floor of the room.

Reflected sounds or room reverberations are extremely important as they directly collect together with the direct sound from the speaker at the listener position. While the direct sound is solely dependent on the axial response of the transducer device, the room reverberant feed developed by the transducer device depends on the total acoustic output of the speaker. Therefore, if the on-axis response of a given transducer device is flat but the total acoustic output of the speaker is not flat, the room reverberant field will be exaggerated or distorted accordingly and will be combined with the direct sound. Deteriorates the sound quality of. The drawbacks of the conventional box type speaker in this respect are well known. The omnidirectional or shape type response speaker is better than the conventional one, but as far as the above points are concerned, the above-mentioned b. It has the drawbacks described in the prior art and problems.

Listeners accept these drawbacks as they are always heard by the transducer device. However, once the sharpness and realism of excellent responsiveness is heard, the technological advancement is immediately apparent.

Certain modifications to the structure of this transducer device do not have to do this, yet retain its capabilities.

The positions of the bass / midrange speaker and the treble speaker should not be changed or exchanged with each other. High frequency output must be at ear level. Also, at this time, the base enclosure is inconvenient, but it must be above the acoustic dispersion sphere, and floor loading of the bass frequency port is omitted.

Another less desirable modification is to position the ducted port 3 on the side of the base enclosure 1 rather than on the bottom 10. As a result of the measurement, there is a low frequency response loss reaching the lower limit response of 30% or more than that obtained with the duct type port provided at the bottom of the base enclosure. It is believed that the improvement is due to the large low frequency phase delay from the bottom duct port due to the large distance from the bass / midrange speaker.

Substituting an auxiliary baffle radiator (ABR) at the bottom of the truncated base enclosure will give results similar to those obtained with ducted port 3. ABR is a flat, elastically mounted, rigid diaphragm 11 whose diameter is approximately
It is 30 cm.

F. Effects of the Invention The effects of the present invention are, in its embodiment, for excellent sound reproduction in four user market areas: home stereo and video, sound recording and volume control, sound enhancement for music and vocal music, and instrument amplification. In the provision of competence.
For convenience, the transducer device according to the present invention will hereinafter be referred to as the speaker of the present invention.

The improved capability of the speaker of the present invention is that the omnidirectional acoustic dispersion and flat total acoustic output without significant anomalies are compared to other omnidirectional or directional response speakers according to the prior art, especially ordinary front emission box speakers. It is based on the newly disclosed device for simultaneously achieving the frequency-to-frequency relationship. For the sake of convenience, these properties are hereinafter referred to as spatial properties or spreadability.

Another important feature of the present invention is about a four-fold increase in the maximum acoustic power output obtained from a conventional dome type treble speaker due to the increased efficiency obtained by the mounting configuration of the treble speaker. This efficiency improvement solves the usual high frequency power handling limitations of typical home stereo loudspeakers and the attendant treble speaker failure. Therefore, in terms of application, this new structure significantly enhances the speaker's ability to reproduce the wide dynamic range of compact disc recording, and achieves a higher sound output level required in the field of professional sound reinforcement requiring omnidirectional dispersion. It makes it easy to meet.

Home stereo application The use of the speaker of the present invention provides a more natural sound reproduction and a more accurate sound stage than the conventional speaker for the following reasons.

[First Reason] With the speaker of the present invention, the same sound fidelity can be obtained anywhere in the room, and as a result, a good stereo image enlarged area can be formed, thereby listening to a satisfactory sound fidelity and image. It frees your hands from having to sit in just one "comfortable spot". This results in an even 360 ° horizontal and ± 60 ° vertical dispersion of the speaker of the present invention, which property provides a complete effective listening range with minimal early reflections from the floor and ceiling.

[Second Reason] The speaker of the present invention expands the total reverberant field in a room that is spatially and spectrally correct, and does not generate distortions other than those generated by the room itself and simply directly Increase the sound level.

Home large screen video application aspect The speaker of the present invention can be effectively used for movie stereo sound reproduction because the spatial response characteristics easily create an illusion of sound coming from the screen instead of the speaker. The production of movie sound effects is also improved by the dynamic range and long end frequency response of the speaker.

Recording and Volume Control Applications By using the speaker of the present invention, recording engineers perform much faster mixdowns and more easily achieve the most desirable musical balance, using these on a normal wall mounted professional monitor. It can be carried out with less ear fatigue that is usually seen. The speaker of the present invention has been demonstrated by the evaluator to provide more accurate criteria for musical balance, better production of fine musical details and the ability to more accurately position the instrument on the acoustic stage. .

These advantages arise for the same reasons as explained in the section on using home stereo. The acoustically controlled room is designed to be acoustically correct with harmonious, high-quality loudspeakers mounted above and in front of the console, but since the room is usually small, the effect of speaker spatial response to room reverberation Is very important in terms of sound reproduction quality and stereo image.

Control room loudspeakers are generally expected to be capable of operating at high sound output levels, which is why the use of home stereo type loudspeakers is dismissed and more efficient and expensive professional audio types are preferred.
Instead, what was lost was the smoothness of responsiveness for increased efficiency. This compromise is avoided by the use of the speaker of the present invention, which provides both smoothness of response and proper sound output capability.

Acoustic enhancement of music and voice The use of the speaker of the present invention provides some novel advantages over generally accepted methods of emitting sound toward an outer audience using a directional front-emitting speaker, as described below. .
This method has two drawbacks. That is, firstly, the output of the acoustically-enhanced loudspeaker is directed away from the speaker, singer, performer, etc., so that they cannot hear clearly. They can only hear the rear radiating sound of the loudspeaker and the confusing reverberation from the audience. Therefore, the stage monitor speaker is used for the performer. However, although this speaker helps, it is not ideal in that it enhances the feedback tendency and the director is not able to hear the audience.

The second drawback is that loudspeakers are a variation of the box type and do not exhibit a flat power response.
Therefore, in particular, the accurate reverberant sound field is not formed to the side and behind the normal radiation angle of the player and the speaker where the microphone is placed. This not only distorts the intelligibility of the sound as heard by the performer as described above, but also creates a very flat acoustic field for the microphone, which increases the tendency for feedback.

In the case of the loudspeaker of the present invention, the radiation pattern covers the performer and the audience, eliminating the need for a stage monitor and emitting the same sound to the audience and the performer solves the above problems. Feedback propensity is reduced and high sound output performance provides adequate sound levels in all and most difficult situations.

Increase in Musical Instrument An advantage obtained by the speaker of the present invention is that sound is emitted non-directionally in the same manner as an acoustic instrument. Therefore, it is possible to develop an amplified acoustic field that is naturally and musically and at the same time shows an even distribution over the entire listening area.
The beam effect characteristic of the conventional speaker, that is, the beam effect that tends to cause a high-pitched sound inconveniently on the axis is not seen for the purpose of appropriately listening at a place apart from the axis.

The speaker of the present invention has been rated as excellent by musicians and is said to have no high level sound pressure effect when tested on keyboards, electric drums, electric bass or guitars and acoustic basses and guitars with electric pickups. .

[Brief description of drawings]

FIG. 1 is a perspective view of the structure of an electroacoustic transducer device according to an embodiment of the present invention showing the layout of a main room, and FIG. 2 is a first view using an auxiliary baffle radiator (ABR).
FIG. 3 is a fragmentary perspective view of the bottom of the figure, FIG. 3 is a fragmentary perspective view showing a modified embodiment in which the high frequency speaker is attached to the top of the acoustic dispersion sphere, and FIG. 4 is an additional high frequency speaker. It is a fragmentary perspective view which shows another Example attached to the top of a dispersion sphere. 1 ... Base enclosure, 2 ... Legs, 3 ... Duct-shaped port, 4 ... Acoustic dispersion sphere, 5 ... High-range speaker, 6
...... Vertical member, 10 ...... Bottom part, 12 ...... Low / mid range speaker, 13 ...... Horizontal member, 14 ...... Partial sphere, 15 ......
Truncated pyramid.

Claims (10)

[Claims] 1. A base enclosure (1) having a side and a bottom (10) and a top being formed by a truncated pyramid (15), and attached to the surface of the truncated pyramid (15). Bass / intermediate speaker (12) oriented so as to emit sound outward and a vertical member (6) mounted on the base enclosure (1) for the bass / intermediate range. Acoustic dispersion sphere (4) supported above the range speaker (12), and partial sphere (14) coaxially supported above the acoustic dispersion sphere (4) by the vertical member (6). ) And a speaker for high range (5) provided on at least one of the acoustic dispersion sphere (4) and the partial sphere (14), the high range speaker (5) being the acoustic dispersion sphere. Orient the sound to radiate into the space formed between (4) and the partial sphere (14). And are electro-acoustic transducer devices. 2. The treble speaker (5) is attached to the partial sphere (14) and is oriented to radiate downward sound into the space. A transducer device according to paragraph 1. 3. The treble speaker (5) is attached to the top of the acoustic dispersion sphere (4), faces upward toward the partial sphere (14), and directs sound into the space. A transducer device according to claim 1, which is oriented so as to radiate to the. 4. Two treble loudspeakers (5,5 ') are used facing each other, one mounted upwards on the acoustic dispersion sphere (4) and the other downwards on the partial sphere (14). A transducer device according to claim 1 mounted on a. 5. The sag between the diaphragm of the high frequency speaker (5) and the acoustic dispersion sphere (4) is about 1 mm.
A transducer device according to claim 1 wherein: 6. A transducer device according to claim 1, wherein the sag between the diaphragm of the high frequency speaker (5) and the partial sphere (14) is about 1 mm. 7. The transducer device according to claim 4, wherein the sag between the diaphragm of the high-frequency speaker (5) and the diaphragm of the high-frequency speaker (5 ') opposed to the diaphragm is about 1 mm. . 8. Transducer device according to claim 1, wherein the sides and the bottom (10) of the base enclosure (1) are tapered by at least 16 cm / meter. 9. Transducer device according to claim 1, wherein the base enclosure (1) has more than two sides. 10. The acoustic dispersion sphere (4) has a diameter of approximately axial alignment with respect to the treble speaker (5).
20-30% rearward, while maintaining constant sag between the acoustic dispersion sphere (4) and the treble speaker (5) for the bass / midrange The acoustic relationship among the speaker (12), the acoustic dispersion sphere (4), and the high-range speaker (5) attached to the partial sphere (14) is changed so that a high hemispherical front of the high frequency sound is generated from the transducer device. Transducer device according to claim 2 for obtaining radiation.