KR20010083946A - Loudspeakers Comprising a Phase Uncorrelated Diffuse Sound Source - Google Patents

Abstract

A loudspeaker comprising a phase uncorrelated diffuse sound source and a duct or wave guide coupled to the sound source to direct acoustic energy from the source, the duct or wave guide having a substantially parallel section extending from the vicinity of the sound source and a termination positioned remotely from the panel.

Description

Loudspeakers Comprising a Phase Uncorrelated Diffuse Sound Source

New Transducers Limited's WO98 / 43464 has a lid hinged to the keyboard and body and is specified by a resonant panel loudspeaker and is preferred from a display screen attached to the lid and from an acoustic wave guide or loudspeaker. A personal computing device having a body with a fallopian horn that directs sound output in a direction.

The present invention relates to a loudspeaker. It is an object of the present invention to provide a means by which sound from a loudspeaker can be connected to one or another remote location.

The invention is schematically illustrated by the following examples in the accompanying drawings.

1 is a front cross sectional view of a first embodiment of the present invention loudspeaker.

2 is a side cross-sectional view of the loudspeaker of FIG. 1.

3 is a front cross-sectional view of a second embodiment of the present invention loudspeaker.

4 is a side cross-sectional view of a third embodiment of the present loudspeaker.

5 is a side cross-sectional view of a fourth embodiment of the present invention loudspeaker.

6 is a side cross-sectional view of a fifth embodiment of the present invention loudspeaker.

7 is a side cross-sectional view of a sixth embodiment of the inventors loudspeaker.

8 is a side cross-sectional view of a seventh embodiment of the inventor loudspeaker,

9 is a detailed view of the correction unit.

The present invention provides a loudspeaker consisting of an uncorrelated phase diverging sound source and a duct or wave guide connected to the sound source for guiding acoustic energy from the source. The duct or wave guide consists of substantially parallel portions extending from the vicinity of the sound source and terminations away from the panel.

The sound source may comprise a bending wave mode acoustic emitter panel. The transducer can be fixed to the panel to excite a resonant bending wave, the resonant bending wave modes associated with each axis of the panel can be arranged to interleave in frequency and the transducer position is resonant bending It may be preferentially chosen to bind to the wave mode.

The duct may be formed with a narrow cross section, or may have another preferred cross section.

The duct may have a fallopian tube shape at its end.

The panel may be located in the duct to combine acoustic radiation from both sides of the panel.

Acoustic reflections can be connected to the duct and the sound source to guide the acoustic radiation into the duct.

The duct may have a plurality of terminations and they may be located along the duct.

The plurality of panels can be connected to the duct.

The duct may be in a folded state.

The loudspeaker may include an attenuator that controls the sound output from the duct termination.

Means may be provided for dividing the duct into a plurality of wave guides extending along the duct. The duct can be divided in two directions, transversely and longitudinally.

The acoustic reflector may be arranged to direct sound output from the duct termination.

Enclosure means may surround one side of the panel.

The plane of the panel may be parallel to the axis of the duct.

Although the present invention has been described with respect to loudspeakers, it may be found in other applications such as microphones or passive or active acoustic absorbers.

The present invention generally relies on the uncorrelated phase radiation properties of a generator or sound source, such as a flat resonant curved wave panel. In WO79 / 09842, for example, the resonant flexural wave panel allows for coupling to acoustic fluid (usually air) contained in a shallow volume well coupled to an acoustic energy source. In contrast to correlated coupling such as piston-type devices, which have problems caused by path length differences, phase cancellations and uneven power continuity, the divergent source preferably incorporates acoustic forces across its radial plane, The acoustic force can be transmitted to the far distance through the duct by fluid coupling. Modal resonance, which occurs frequently in ducts, is mitigated by the uncorrelated divergence of acoustic energy entering the ducts.

If the narrow grooves or similar gaps are multidirectional, the duct terminations can be directly radiated if the frequency cannot be controlled or selected. If altered directional characteristics are required, a combination of various sizes, shapes and acoustic fallopian tubes known in the art can be added to the open end of the duct.

The principle of diffuse coupling can be extended to a single reflective element, such as a degenerate fallopian tube or part of a duct, and the length of the duct can vary to the point where the fallopian tube part is directly provided to the source. Can be changed.

A prominent feature of the present invention is that the duct can be provided in the plane of the radiator to have an effective action. Acoustic energy may also be split at the surface of the source and guided to one or more ducts or wave guides. And the duct or wave guide can have different lengths, and if necessary, multiple outputs can be recombined smoothly after passing through the duct or wave guide.

Twin ducts can be used to utilize the energy from both sides of the emanation source. The preferred source is one or more curved wave panels, but the other sources are provided by a series of conventional small piston speakers that are supplied with a random signal in phase, or by a signal that is properly processed to provide divergent acoustic action. It includes a series of digital speaker elements that are driven. The duct provides a beneficial integration function that can be designed as a low pass acoustic filter to complete the desired response from a series of digital speaker elements.

Twin ducts can be installed laterally to provide sound from two separate locations, one across the center or near the center, across the passenger side space of the vehicle.

The duct may be straight, curved or folded so that the thin assembly is properly installed in difficult locations where conventional speakers could not.

A wide range of sound can be directed to a substantially small radiation gap, such as a groove in the side of a television monitor, usually hidden behind an acoustically transmissive grating. Duct performance can be further improved by disturbing cross standing waves due to the subdivision of the cell structure.

Ducts and / or fallopian tubes have a low frequency loading function that can simply be calculated using lumped parameters. The sound source can thus be effectively loaded to increase low range performance by the added / harmonized air mass and by the baffle effect due to the extension path length between the front and rear of the properly located sound generator.

The rear of the panel or multiple panels (guided or shaped by the same or frequency selective / differential area) or the rear of the multiple cone-shaped acoustic generators for additional resonance enhancement and control of the low frequency acoustic path between the front and the rear. It has a rear chamber partially or fully enclosed.

The height and / or cross sectional area of the duct influences the determination of higher frequency points for the smooth transfer of acoustic energy. So a 30mm high rectangular duct will show a frequency dependence above 10kHz, while a 10mm high cross section will have good performance above 25kHz.

In addition to the laterally subdivisions of the duct, the subdivisions of the duct may extend in the vertical direction to further subdivide the duct for maintained transmission performance at higher frequencies.

The exit area of the duct induced by the source of divergence affects the amplification, and various area mechanisms, such as blanking plates moving on the duct end relative to the inherent area of the exit, expand without significant loss of sound quality. It can provide a convenient and effective form of control. A fallopian tube guide element can be applied behind the mechanical loudness control device. The user volume control can thus be far from the sound generator. Optionally, the duct control device will be provided at any convenient location along the duct.

The fallopian tube end is easily guided by the duct of the present invention, the fallopian tube can provide effective and predictable directional control of the diverging source. Duct terminations independently provide a uniform, wide angle of radiation, an almost complete groove or a point source nearby.

For the coincidence effect that causes deviations from the axial lobes of the force at individual frequencies for the unique design of the flexural panels, the fluid coupling and duct integration action changes the acoustic energy again and thus the direct The effect is no longer in the form of the final sound output.

The duct may have some length and the terminations may be provided along the length of the duct to simply provide a distributed low level acoustic system. Multiple resonant panels are supplied in one duct and the multiple panel arrangement can be made smaller by folding or bending the area before the panel and behind the duct.

In the drawings, as shown in FIGS. 1 and 2, the loudspeaker 1 usually comprises a resonant bending wave panel 2 of the kind described in the applicant's international patent application WO97 / 09842. The resonant flexural wave panel is driven by a vibration exciter 3 which is supplied with an electrical audio signal from a suitable audio amplifier (not shown). The panel 2 is elastically installed by each corner on a resilient suspension 4 in the form of a duct 6 like a shallow depth groove having parallel sides in the housing 5. The duct 6 has a closed end 7 and an open end 8, which open at an open fallopian tube part 9 and form an end at the open or end 10. The housing may be made of a material that does not cause resonance, such as a material that constitutes the enclosure of the loudspeaker, such as a medium density fiberboard or plastic. Optionally, at least the duct may be made of a material having a suitable density so as not to substantially cause resonance in the intended use frequency range. Thus, the duct may be in the form of a highly dense pipe such as polyethylene, for example.

The duct and fallopian tube portions are divided into waveguides by a divider 12 extending along the duct and fallopian tube portions.

3 is an embodiment of a loudspeaker similar to the loudspeakers of FIGS. 1 and 2; In this case, however, the interior or closed end 7 of the duct 6 is formed as a reflector in the form of a curve, for example a parabolic shape, in order to reflect acoustic radiation from the panel 2 towards the open end of the duct 6. Also in this embodiment, the plane of the panel 2 is installed at right angles to the direction of the duct while in FIG. 1 and 2 the plane of the panel is installed in the direction of the duct. Furthermore, in this embodiment the fallopian tube part is flared outwardly or curved, while in the embodiment of FIGS. 1 and 2 the fallopian tube part is conical.

4 shows a loudspeaker arrangement as shown in FIGS. 1 and 2, wherein the housing 5, which forms a duct 6 with parallel sides, has an open end 8 and a closed end 7 at which the duct ends. . The housing sustains the resonant flexural wave panel 2 on the resilient suspension 4 so that acoustic radiation from one side 17 of the panel facing into the housing 5 is guided along the duct to a remote location. The acoustic radiation here is emitted from the open end of the duct.

The loudspeaker shown in FIG. 5 is the same as that shown in FIG. 4 except for the duct whose end is formed by a horn 9.

The loudspeaker of FIG. 6 is similar to the loudspeaker of FIG. 5, but in this case acoustic radiation from the side 15 of the panel facing away from the duct is contained in the cavity 14. The cavity 14 is here defined by an enclosure 13 fixed to the device with the housing 5 to prevent radiation from the side 15 of the panel 2 from being exposed to the ambient circumference. .

The loudspeaker of FIG. 7 is similar to the loudspeaker of FIG. 4, in which case the housing 5 has a duct 6 having a pair of parallel side faces in opposite directions, the ducts having each face or side of the panel 2. It is associated with (15) and extends in opposite directions to each other, the direction of each open end (8).

FIG. 8 is a modification of the loudspeaker of FIG. 7 wherein two ducts 6, each associated with one face of the panel 2, extend in the same direction and at intervals.

9 illustrates that the end 8 of the duct 6 of the loudspeaker described above can be modified by installing an acoustic reflector 16 near the end of the duct to collect and guide the sound in the direction of the arrow. So the reflector is parabolic.

The present invention therefore provides a mechanism of a simple loudspeaker for guiding sound to distant locations.

Claims (16)

It consists of an uncorrelated phase diverging sound source and a duct or wave guide coupled to the sound source for guiding acoustic energy from the source, the duct or wave guide extending substantially in parallel from the vicinity of the sound source. And an end portion positioned away from the panel. The method of claim 1, And said acoustic source comprises a flexural wave mode acoustic emitter panel. The method of claim 2, A transducer fixed to the panel to excite the resonant bending wave, the resonant bending wave mode being associated with each axis of the panel aligned to be interleaved with frequency and the transducer position is preferentially coupled to the resonant bending wave mode. A loudspeaker characterized in that it is selected. The method according to any one of claims 1 to 3, The duct is characterized in that the cross-section is characterized by a narrow slot (slot). The method of claim 1, wherein The duct is a loudspeaker, characterized in that the end portion is formed in the fallopian tube portion. The method according to any one of claims 2 to 5, And the panel is installed in the duct to couple acoustic radiation from both sides of the panel. The method of claim 1, wherein A loudspeaker comprising an acoustic reflector coupled to the duct and a sound source to direct acoustic radiation to the duct. The method of claim 1, wherein And said duct comprises a plurality of terminations. The method according to any one of claims 2 to 8, A loudspeaker comprising a plurality of panels coupled to a duct. The method of claim 1, wherein And the duct is folded. The method of claim 1, wherein A loudspeaker comprising an attenuator for controlling the sound output from the duct termination. The method of claim 1, wherein And a means for dividing the duct into a plurality of wave guides extending along the duct. The method of claim 12, And the duct is divided in two directions. The method of claim 1, wherein And a sound reflector mounted to direct sound output from the duct termination. The method according to any one of claims 2 to 5, A loudspeaker comprising an enclosure means surrounding one side of the panel. The method according to any one of claims 2 to 15, And the plane of the panel is parallel to the axis of the duct.