Two-way loudspeaker with floating waveguide

Abstract

Loudspeaker (100, 200), comprising: a loudspeaker enclosure (102, 202); a low-frequency (LF) driver (104, 204) arranged in the loudspeaker enclosure (102, 202) and having a radiating surface (220) configured to radiate acoustic LF energy, and having a radiating surface aperture (228) defined by an outer circumference of the radiating surface (220);and an LF waveguide (216) defining a first radiation path (222) for acoustic LF energy, wherein the LF waveguide (216) has a proximal opening (224) located adjacent to the LF driver (104, 204) and extending away from the LF driver (104, 204) to a distal opening (234) to define the first radiation path (222) through it, wherein the proximal opening (224) has a proximal opening area smaller than a radiation surface opening area to define a second radiation path (230) for the acoustic LF energy around an outer surface (232) of the LF waveguide (216).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 62 / 278,959, filed January 14, 2016, and U.S. Provisional Application Serial No. 62 / 278,952, filed January 14, 2016, the disclosures of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD

[0002] The present disclosure relates to a two-way loudspeaker design with condensed geometry between high-frequency and low-frequency drivers, and more particularly to a two-way loudspeaker design with a floating waveguide in front of the low-frequency driver. GENERAL STATE OF THE ART

[0003] A loudspeaker is an acoustic system that typically includes a speaker cabinet, at least one driver, and a crossover network. A loudspeaker driver is an electroacoustic transducer that converts an electrical audio signal into corresponding sound. The dynamic loudspeaker driver is the most commonly used type. When an AC electrical audio signal is applied to its voice coil (a coil of wire suspended in a circular gap between the poles of a permanent magnet), Faraday's law of induction causes the voice coil to move rapidly back and forth, causing a (usually conical) diaphragm attached to the coil to move back and forth, creating sound waves by exerting pressure on the air.

[0004] A direct-radiating loudspeaker has two main operating regions—the piston-like region and the adjacent upper decade of the spectrum. The piston-like region is defined as the frequency range between the mechanical resonance of the loudspeaker (i.e., the lower limit) to the spectrum region where the wavelength is equal to the radiating surface (or diaphragm) of the loudspeaker (i.e., the upper limit). The piston-like region is the optimal operating region of a direct-radiating loudspeaker. The adjacent upper decade of the spectrum, where the wavelength is smaller than the radiating device, exhibits efficient energy delivery but is affected by mechanical cone breakup modes and erratic directivity. This region, although prone to error, is important in many designs and is the critical operating region for one or more embodiments of the present disclosure.

[0005] The majority of loudspeaker designs are simple two-way, meaning they have two radiating elements (called drivers)—a high-frequency (HF) driver and a low-frequency (LF) driver. This design is popular due to its moderate cost, simplicity, and moderate cabinet size. This two-way arrangement also represents the minimum number of elements capable of effectively reproducing the musical spectrum. In the professional loudspeaker market, larger LF drivers (e.g., > 10 inches) are often preferred due to their improved low-frequency performance and overall acoustic output. In this case, the region above pistonic behavior must be utilized. Character list Fig. 1 represents a most favorable simplification of the acoustic result for common loudspeaker designs with a typical two-way driver orientation; Fig. 2 illustrates a best-case simplification of the acoustic result for a loudspeaker design having a condensed two-way driver alignment geometry according to one or more embodiments of the present disclosure; Fig. 3 is an exemplary cross-sectional side view of a loudspeaker according to one or more embodiments of the present disclosure; and Fig. 4 is an exemplary exploded view of the loudspeaker of Fig. 3 according to one or more embodiments of the present disclosure. SUMMARY

[0006] One or more embodiments of the present disclosure relate to a loudspeaker comprising a loudspeaker enclosure, a low frequency (LF) driver disposed within the loudspeaker enclosure, and an LF waveguide. The LF driver may have a radiating surface configured to radiate LF acoustic energy and a radiating surface opening defined by an outer perimeter of the radiating surface. The LF waveguide may define a first radiation path for LF acoustic energy. The LF waveguide may have a proximal opening disposed adjacent to the LF driver and extending away from the LF driver to a distal opening to define the first radiation path therethrough.The proximal opening may have a proximal opening area that is smaller than a radiating area opening area to define a second radiation path for the LF acoustic energy around an outer surface of the LF waveguide.

[0007] An inner surface and an outer surface of the LF waveguide may have a generally equal acoustic pressure from the LF driver. The second radiation path may exit the loudspeaker enclosure at a front surface. The second radiation path may exit the loudspeaker enclosure along at least one of a side surface and a rear surface. The loudspeaker may further include a load plate immediately forward of a portion of the radiation surface and adjacent to the LF waveguide to redirect the LF acoustic energy along the second radiation path to a rear acoustic exit in the rear surface.

[0008] A proximal end of the LF waveguide may not be physically connected to the LF driver. The proximal end of the LF waveguide may include a bottom edge and a top edge that at least partially define the proximal aperture. The bottom edge may be closer to the radiating surface aperture than the top edge. Furthermore, the bottom edge may be closer to a radiation centerline of the LF driver than the top edge.

[0009] The loudspeaker may further comprise a high-frequency (HF) driver disposed in front of the radiating surface of the LF driver and at least partially blocking the LF acoustic energy radiated from the radiating surface. A radiation center axis of the LF driver and a radiation center axis of the HF driver may be at an offset angle. The HF driver may not be coaxial with the LF driver.

[0010] The loudspeaker may further comprise an RF driver disposed adjacent to the LF driver, wherein a first distance between an acoustic center of the LF driver and an acoustic center of the RF driver is less than one wavelength at the crossover frequency. For example, the first distance may be less than 5 inches (12.7 cm). A second distance from the acoustic center of the RF driver to a radiation center axis of the LF driver is less than a radius of the radiating surface aperture.

[0011] One or more further embodiments of the present disclosure relate to a loudspeaker comprising a loudspeaker enclosure, an LF driver disposed within the loudspeaker enclosure, an RF driver, and an LF waveguide. The LF driver may have a radiating surface configured to radiate LF acoustic energy and a radiating surface opening defined by an outer perimeter of the radiating surface. The RF driver may be disposed in front of the radiating surface of the LF driver and at least partially block the LF acoustic energy radiated from the radiating surface of the LF driver. The LF waveguide may define a first radiation path for the LF acoustic energy.The LF waveguide may have a proximal opening disposed adjacent to the LF driver and extending away from the LF driver to a distal opening to define the first radiation path therethrough. The proximal opening may have a proximal opening area smaller than a radiating surface opening area to define a second radiation path for the LF acoustic energy around an outer surface of the LF waveguide. The distal opening of the LF waveguide may have a distal opening area larger than the radiating surface opening area. The proximal opening may be spaced from the LF driver by a distance to define an air gap between the radiating surface of the LF driver and the proximal opening of the LF waveguide.

[0012] A radiation center axis of the LF driver and a radiation center axis of the HF driver may be offset. The second radiation path may exit the loudspeaker cabinet along at least one of a side surface and a rear surface.

[0013] One or more further embodiments of the present disclosure relate to a loudspeaker comprising a LF driver having a radiating surface configured to radiate LF acoustic energy, and an RF driver that at least partially blocks the LF acoustic energy radiated by the LF driver. The radiating surface may have a radiating surface opening defined by an outer perimeter of the radiating surface. An acoustic center of the RF driver may be offset from a radiation center axis of the LF driver.

[0014] The loudspeaker may further include an LF waveguide defining a first radiation path for the LF acoustic energy. The LF waveguide may have a proximal opening disposed adjacent to the LF driver and extending away from the LF driver to a distal opening to define the first radiation path therethrough. The proximal opening may have a proximal opening area smaller than a radiating surface opening area to define a second radiation path for the LF acoustic energy around an outer surface of the LF waveguide. The distal opening of the LF waveguide may have a distal opening area larger than the proximal opening area. The LF waveguide may be detached from the LF driver to define an air gap between the radiating surface of the LF driver and the proximal opening of the LF waveguide. DETAILED DESCRIPTION

[0015] As required, detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely examples of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or reduced to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art to variously employ the present invention.

[0016] The loudspeaker operating range, encompassing the crossover frequencies between the HF and LF drivers, is called the crossover area. Performance in this range depends specifically on the acoustic summation of the two drivers. The distance between drivers contributes significantly to determining the stable operating solid angle for the crossover area. An important design goal for the crossover area is that this solid angle matches the operating radiation envelope of the individual drivers, which should also match each other. Greater driver distance results in a smaller crossover operating angle, with erratic behavior outside this solid angle.For a professional loudspeaker whose primary design goal is uniform sound coverage for a large audience, this is not insignificant, as most listeners are located in the off-axis region and the crossover occurs in the center of the sound spectrum. The result is missing and / or distorted audible content for a large portion of the listener, with the problems typically occurring in the speech range.

[0017] One or more embodiments of the present disclosure significantly improve the crossover performance of two-way loudspeakers that utilize large LF drivers. These embodiments specifically contribute to mitigating the following: ( 1 ) poor bundling next to the axis in the takeover area due to the distance between the drivers; ( 2 ) poor focusing of the LF driver in the area above the piston-like behavior; and ( 3) poor LF performance due to cone breakup.

[0018] To achieve this, a two-way loudspeaker design is provided that, briefly put, enforces a condensed geometry between an LF driver and an HF driver and then "floats" a midrange-sized waveguide in front of the LF driver. While this design shares similarities with coaxial designs, it is specifically non-coaxial. Rather, the loudspeaker design of the present disclosure is a hybrid design intended to benefit from the close proximity of acoustic centers without introducing a center-axis obstruction to the LF driver. Furthermore, the LF and RF waveguides and associated acoustic elements can be used to redirect very low-frequency energy not adequately supported by the smaller LF waveguide to escape unimpeded via alternative acoustic radiation paths.The details of this are explained in more detail below and can involve several crucial functional steps.

[0019] The typical and simplest arrangement of drivers in a loudspeaker is along a vertical line on a simple baffle. The distance between the drivers in this case depends on the driver size. In two-way designs with large LF drivers, the distance can prevent good crossover characteristics. Fig. 1 is a simplified schematic diagram of a typical two-way loudspeaker 100 . Fig. 1 represents a most favorable simplification of the acoustic result for common loudspeaker designs with a typical two-way driver orientation. The representation in Fig. Figure 1 shows the basis of the transfer summation equation. Specifically, Fig. 1 the speaker 100 which is a loudspeaker cabinet 102 , a LF driver 104with an acoustic center 106 and an RF driver 108 with an acoustic center 110 has.

[0020] Each driver radiates acoustic energy, and this energy, when viewed momentarily, takes the form of individual pressure waves. Fig. 1 represents a LF energy wavefront 112 , which represents the acoustic energy produced by the LF driver 104 radiated, and an RF energy wavefront 114, which represents the acoustic energy emitted by the RF driver 108 Each wavefront has a propagation speed (i.e., the speed of sound in air) and therefore has a travel time from the driver to the listener. For good crossover summation, the LF energy wavefront 112 and the RF energy wavefront 114 be aligned at a 1 / 4 wavelength.

[0021] When the drivers are separated, an included angle develops where the wavefronts are aligned, and the summation is positive. Outside this angle, the summation is largely subtractive. A loudspeaker design goal is to align the drivers such that a pathlength alignment angle P subtends a directivity angle D. The pathlength alignment angle is the region where good summation occurs between the HF and LF drivers (e.g., the wavefronts lie between 1 / 4 wavelength). The directivity angle D is the designed operating (i.e., coverage) angle of the loudspeaker and is based on the coverage envelopes of the individual drivers. As in Fig. 1, the beamwidth angle D is larger than the pathlength alignment angle P and the two have only a partial overlap (i.e. the drivers 104 and 108do not agree in most of the design operating angle).

[0022] As stated above, Fig. 1 is a most favorable simplification of the actual acoustic result. First, there is a 3 dB difference between coherence and 1 / 4 wavelength summation (i.e., there is a 3 dB variance in the pathlength alignment angle). Second, the actual phase waves of the drivers are much more complex (and frequency-dependent) than the simple equal-pathlength circles representing the energy wavefronts. 112 , 114 represent in Fig. 1 drawn from the acoustic centers 106 , 110 . The representation in Fig. Figure 1 shows the basis of the summation equation, but the actual path length orientation angle P will always be smaller than shown.

[0023] There are several design changes, each with a corresponding design penalty, that can center the pathlength alignment angle P inside the directivity angle D. These design changes can be helpful, but do not increase the pathlength alignment angle P. To expand the pathlength alignment angle P, the HF and LF acoustic centers can be brought closer together, and the phase wave of each driver can be shaped similarly.

[0024] The loudspeaker design of the present disclosure may utilize a condensed geometry between the HF and LF drivers. This may be achieved in various ways, including the use of phase plugs. According to one or more embodiments, the loudspeaker design may utilize a geometry similar to that described in Fig. Use 2 shown. Fig. Figure 2 is a simplified exemplary schematic diagram of a loudspeaker 200 according to one or more embodiments of the present disclosure. Specifically, Fig. 2 illustrates a most favorable simplification of the acoustic result for a loudspeaker design having a condensed two-way driver alignment geometry according to one or more embodiments of the present disclosure. As in Fig. 1 the speaker can 200 out of Fig. 2 a loudspeaker cabinet 202, an LF driver 204 with an acoustic center 206 and an RF driver 209 with an acoustic center 210 The RF driver 208 can be adjacent to the LF driver 204 be arranged such that a distance between the acoustic center 206 of the LF driver 204 and the acoustic center 210of the RF driver 208 is less than one wavelength at a crossover frequency. As an example, the distance between the acoustic centers may be less than 5 inches (12.7 cm).

[0025] As shown, by using this condensed geometry between the acoustic centers 206, 210 of the LF and HF drivers 204 , 208 the focusing angle D is sufficiently in the path length alignment angle P (i.e. the LF and HF drivers 204 , 208 are fully aligned at the designed operating angle). Similar to Fig. 1 represents Fig. 2 a LF energy wavefront 212 , which represents the acoustic energy produced by the LF driver 204 radiated, and an RF energy wavefront 214 which represents the acoustic energy emitted by the RF driver 208 Furthermore, both the LF driver 204 as well as the RF driver 208in the transfer area to an LF waveguide 216 and an RF waveguide 218. Therefore, the LF energy wavefront 212 and the RF energy wavefront 214 has a more similar shape.

[0026] The LF driver 204 can be a radiating surface 220 which is sometimes referred to as a cone or diaphragm and is designed to radiate acoustic LF energy. The radiating surface 220 moves like a piston to pump air and generate sound waves in response to electrical audio signals. Due to the condensed geometry of Fig. 2 is the LF driver 204 no longer a simple direct radiator. It now has acoustic obstacles in the form of the HF driver 208 near the radiating surface 220 of the LF driver that inhibit the crossover frequencies. For example, the HF driver 208 in front of the radiating surface220 of the LF driver 204 be arranged in such a way that it at least partially blocks the acoustic LF energy radiated from the radiating surface of the LF driver.

[0027] To achieve a condensed geometry while maintaining good acoustic behavior of the LF driver at all operating frequencies 204 is preserved, the loudspeaker design can use an LF waveguide 216 which is smaller than a traditional low-frequency waveguide. The LF waveguide 216 defines a first radiation path 222 for the acoustic LF energy. The size of the LF waveguide 216 can be carefully selected to the RF waveguide 218so that it can be aligned with the RF waveguide. This allows the two waveguides to have similar focusing properties and length to present acoustic alignment between their respective drivers at the target operating angle.

[0028] Furthermore, the LF waveguide 216 To mitigate the effects of cone breakup and narrowed bundling, a proximal opening 224 which is arranged adjacent to the LF driver 204 (coupled to the driver) and which is substantially smaller than the radiating surface 220 of the LF driver 204 can be. An outer circumference 226 the radiating surface 220 can have a radiating surface opening 228 with a radiation surface opening area. Likewise, the proximal opening 224of the LF waveguide 216 define a proximal opening area. Accordingly, the proximal opening area can be smaller than the radiating surface opening area. Since the proximal opening area can be smaller than the radiating surface opening area, this defines a second radiation path 230 for the acoustic LF energy around an outer surface 232 of the LF waveguide 216 around.

[0029] The LF waveguide 216 can be separated from the LF driver 204 away from a distal opening 234 (coupled to the free air) which form the first radiation path 222 defined through it. The distal opening 234may define a distal aperture area and be sized appropriately for waveguide design practice, as known to one of ordinary skill in the art, to support the focusing criteria. For example, the distal aperture area may be larger than the proximal aperture area. Generally, the larger the distal aperture, the more control over focusing is available. 234 is.

[0030] According to one or more embodiments, the design details for the LF waveguide 216 may include at least two criteria: ( 1 ) the distal opening area of ​​the LF waveguide 216 may be larger than the radiating surface opening area; and ( 2 ) The length and shape of the LF waveguide can be strategically chosen to match the RF waveguide 218 and maintain appropriate phase-wave relationships. The remaining design details for the LF waveguide 216 may vary.

[0031] Typical LF waveguide design follows two approaches. The first is designed to support low frequencies. In this case, the waveguide couples to the entire LF radiating area, usually through a physical, sealed connection to the edge of the LF driver, and must be large enough to support lower frequencies. The second is designed to support mid-range frequencies and follows compression driver techniques (i.e., the driver fires into a compression chamber, with or without a phase plug, and then couples to the waveguide). This can significantly improve high-frequency performance but severely degrade low-frequency performance because the effective radiating area is reduced and the compression chamber can introduce new acoustic elements into the system, such as resistance, mass, and compliance, depending on the design geometry.

[0032] As explained above, a condensed geometry between the LF driver 204 and the RF driver 208 may be a primary design motivation. As further explained above, a smaller LF waveguide 216 a means of mitigating poor driver behavior in the crossover region. According to one or more further embodiments, the LF waveguide 216 before the LF driver 204 A floating waveguide is not physically connected to its corresponding driver, but is detached from the LF driver. As in Fig. 2, the proximal opening 224 of the LF waveguide 216 at a distance from the LF driver 204 spaced to form an air gap 236 between the LF driver 204 and the LF waveguide 216The air gap 236 may be present at least partially, since the proximal opening area of ​​the LF waveguide 216 is smaller than the radiating surface opening area of ​​the LF driver 204 Since the radiation surface 220 moves in response to electrical audio signals, the distance between the LF driver 204 and the LF waveguide 216 and accordingly the size of the air gap 236 vary.

[0033] The LF waveguide 216 floating can be a means of effectively extracting the higher frequencies from the radiating surface 220 of the LF driver 204 directly into the LF waveguide 216 (which is designed to support these frequencies) via the first radiation path 222, without using a compression chamber and without transferring all the acoustic energy into the LF waveguide 216Accordingly, frequencies suitable for the LF waveguide 216 are not optimal, another radiation path should be granted, such as the second radiation path 230 For good performance, several paths may be necessary. Thus, the second radiation path 230 include multiple radiation paths. These additional radiation paths can be created using numerous acoustic elements and are primarily designed to address different frequency ranges.

[0034] Fig. 3 is an exemplary cross-sectional side view of a loudspeaker 300 , using the various design criteria described above, according to one or more embodiments of the present disclosure. Fig. 4 is an exemplary exploded view of the speaker 300 out of Fig. 3. The loudspeaker 300 a loudspeaker cabinet can 302, a LF driver 304 with an acoustic center 306 and at least one RF driver 308 with an acoustic center 310 As shown, the at least one RF driver 308 a first RF driver 308a with an acoustic center 310a and a second RF driver 308b with an acoustic center point 310b. The second RF driver 308b can be further from the LF driver 304 removed than the first RF driver 308a However, the two-way loudspeaker design according to the present disclosure can also be used with only a single RF driver.

[0035] The LF driver can have a radiating surface 320 (or a cone) which has a flexible suspension component, commonly called a spider 342 with a rigid basket or frame 340The centering spider 342 a voice coil 344 can be moved axially through a cylindrical magnetic gap 346 The voice coil 344 can be wound around a coil body 348 wound, which serves as a heat-resistant coil for the wire. When an electrical audio signal is applied to the voice coil 344, the electric current in the voice coil creates a magnetic field, turning it into a variable electromagnet. The LF driver 304 can also use a magnet 350 which is enclosed by a frame 340 , which at least a portion of the voice coil 344 and the coil body 348 surrounding it, is held in position. The magnet 350 generates a standing magnetic field to counteract the variable electromagnetic field of the voice coil 344 The voice coil 344and the magnet system of the LF driver interact, creating a mechanical force that causes the voice coil 344 and thus the attached radiation surface 320 on a first radiation center axis 352 of the LF driver 304 like a piston moves back and forth and generates sound waves in response to the electrical audio signals.

[0036] A dust cap 354 A hole can be made in the middle of the radiating surface 320 The dust cap 354 can reduce the amount of dust and dirt that can enter the gap of the magnet 350, scattering losses through the LF driver 304 reduce and increase the strength of the radiating surface 320 and at the same time help to maintain its shape. A flexible suspension system can support the centering spider 342 and a border 356 include (see Fig. 4). The frame 356can be used on an outer circumference 326 the radiating surface 320 as well as on the frame 340 The suspension system can support the voice coil 344 in the magnetic gap 346 center and exert a restoring force to hold it there, essentially acting like a spring when the driver moves. The centering spider 342 can provide a large part of the restoring force, while the surround 456 can help the voice coil 344 and the radiating surface 320 to center to allow free piston-like movement in alignment with the magnetic gap 346 While the enclosure 356 helps to achieve the maximum mechanical deflection of the radiating surface 320 and the voice coil 344 limit, it can also determine how energy is absorbed that is transmitted through the radiating surface 320 The mass of the moving parts (the radiating surface 320, the dust cap 354 , the voice coil 344 and the coil body) and the flexibility of the suspension (the frame 356 and the centering spider 342) control the resonance (F s ) of the LF driver, which in turn controls its low frequency response.

[0037] As in Fig. 2, the outer circumference 326 the radiating surface 320 define a radiating surface opening with a radiating surface opening area. As shown in Figure 2 the LF driver 304 and the first RF driver 308a have a condensed geometry such that the first RF driver 308a the LF driver 304 at least partially blocked. For example, the first RF driver 308a in front of the radiating surface 320 of the LF driver 304 arranged, although the first HF driver is not coaxial with the LF driver 304Rather, the acoustic center can be 310a of the first RF driver 308a from the first radiation center axis 352 Similar to Fig. 2, the first RF driver 308a adjacent to the LF driver 304 be arranged such that a first distance between the acoustic center 306 of the LF driver 304 and the acoustic center 310a of the first RF driver 308a less than one wavelength at the crossover frequency. As an example, the distance between the acoustic centers may be less than 5 inches (12.7 cm). According to one or more embodiments, a second distance orthogonal to the first radiation center axis 352 from the acoustic center 310a of the first RF driver 308a smaller than a radius of the radiating surface opening 328 be.

[0038] The first RF driver 308acan be physically connected to a first RF waveguide 318a coupled, while the second RF driver 308b physically to a second RF waveguide 318b can be coupled. The first RF driver 308a can transmit acoustic RF energy along a second radiation center axis 358 According to one or more embodiments of the present disclosure, the first radiation center axis 352 (which the LF driver 304 corresponds) and the second radiation center axis 358 (which corresponds to the first RF driver 308a corresponds) at an offset angle. The LF driver 304 can be connected to a LF waveguide 316 which is smaller than a conventional low-frequency waveguide. The LF waveguide 316 defines a first radiation path 322 for the acoustic LF energy. The size of the LF waveguide 316can be carefully selected to become the first RF waveguide 318a so that it can be aligned with the first RF waveguide. This allows the two waveguides to have similar beamwidth characteristics and lengths to present acoustic alignment between their respective drivers at the target operating angle.

[0039] The LF waveguide 316 can have a proximal end 323 with a proximal opening 324 adjacent to the LF driver 304 which are much smaller than the radiating surface opening 328 of the LF driver 304 The proximal opening 324 of the LF waveguide 316can define a proximal opening area. Accordingly, the proximal opening area can be smaller than the radiating area opening area. Since the proximal opening area can be smaller than the radiating area opening area, this defines a second radiation path 330 for the acoustic LF energy around an outer surface 332 of the LF waveguide 316 The LF waveguide 316 can extend away from the LF driver 304 to a distal end 333 with a distal opening 334 extending the first radiation path 322 defined through it. The distal opening 334 can define a distal opening area that can be larger than the proximal opening area.

[0040] Similar to Fig. 2, the LF waveguide 316 before the LF driver 304 float, such that the proximal end 323is not physically connected to the LF driver, but rather from the LF driver 304 is released. The proximal opening 324 of the LF waveguide 316 can be placed at a distance from the LF driver 304 be spaced to create an air gap 336 between the LF driver 304 and the LF waveguide 316 to define. The air gap 336 may be present at least partially, since the proximal opening area of ​​the LF waveguide 316 smaller than the radiating surface area of ​​the LF driver 304 Since the radiating surface 320 moves in response to electrical audio signals, the distance between the LF driver 304 and the LF waveguide 316 and vary the size of the air gap accordingly.

[0041] According to one or more embodiments, the proximal opening 324of the LF waveguide 316 may be circular. For this purpose, the proximal end 323 a lower edge 360 ​​and a top edge 362 The lower edge 360 can be closer to the radiation center axis 352 of the LF driver 304 than the top edge 362 Furthermore, the lower edge 360 can be closer to the radiating surface opening 328 than the top edge 362 In this way, the proximal opening 324 have a constant distance from the radiating surface 320.

[0042] According to one or more alternative embodiments, the proximal opening 324 of the LF waveguide 316 be rectangular. The lower edge can be 360 be a first horizontal edge and the top edge 362 may be a second horizontal edge opposite the first horizontal edge. Furthermore, the proximal end may have two vertical edges 364which, together with the first and second horizontal edges, form the proximal opening 324 Likewise, the first horizontal edge can be closer to the radiation center axis 352 of the LF driver 304 than the second horizontal edge. Furthermore, the first horizontal edge can be closer to the radiating surface opening 328 than the second horizontal edge.

[0043] The LF waveguide 316 floating can be a means of effectively extracting the higher frequencies from the radiating surface 320 of the LF driver 304directly into the LF waveguide 316 (which is designed to support these frequencies) via the first radiation path 322, without using a compression chamber and without driving all frequencies into the LF waveguide. Accordingly, frequencies that are not optimal for the LF waveguide 316 can be granted a different radiation path, such as the second radiation path. 330 Due to the multiple radiation paths, an inner surface 366 and the outer surface 332 of the LF waveguide 316 a generally equal acoustic pressure from the LF driver 304As previously described, multiple paths may be necessary for good performance. Thus, the second radiation path 330 may include multiple radiation paths. These additional radiation paths may be created using numerous acoustic elements and are primarily designed to address different frequency ranges, as discussed below.

[0044] The loudspeaker 300 may contain two inner chambers - an anterior chamber 368 and a rear chamber 370 . The rear chamber 370 can the LF driver 304 in a design with a slotted box. The front chamber 368 can be achieved by enclosing the space immediately in front of the LF driver 304 and behind the LF and HF waveguide 316 , 318 According to one or more embodiments, the front chamber 368 seven ( 7) contain exit paths for the acoustic LF energy. A main exit can be the LF waveguide 316 itself, which is the decisive output for the crossover frequencies via the first radiation path 322 Other acoustic outputs in the loudspeaker 300 may include: a front acoustic output 372 , which is accessed through a front opening 374 in a front surface 376 of the loudspeaker cabinet 302 directly above the LF driver 304 is defined; a lower acoustic output 378 on a bottom surface 380 of the loudspeaker cabinet 302 ; two side acoustic outputs 382 through narrow openings 384 in side surfaces 386 of the loudspeaker cabinet 302 (see Fig. 4); and two rear acoustic outputs 388 in a back surface 390 of the loudspeaker cabinet302 .

[0045] As previously described, the proximal opening 324 of the LF waveguide 316 smaller than the radiating surface opening 328 of the LF driver 304 The levitation of the LF waveguide 316 may only transfer a portion of the acoustic LF energy from the LF driver 304 via the first radiation path 322 into the LF waveguide 316 Instead, the acoustic LF energy can be transferred between the LF waveguide 316 via the first radiation path 322 and the other acoustic outputs via the second radiation path 330. The acoustic LF energy can follow the path of least resistance. The loudspeaker design according to the present disclosure utilizes this property to optimize performance. The arrangement of the proximal opening of the LF waveguide 316 near the center of the radiating surface 320which ensures close coupling of the voice coil 344 generated, the higher crossover frequencies can enter the LF waveguide 316 support financially.

[0046] Crossover frequencies coming from outer sections of the radiating surface 320 are generally the acoustic LF energy that produces the erratic behavior outside the piston-like operating range. The second radiation path presents itself as an acoustic low-pass filter and prevents this specific acoustic LF energy from escaping at other outputs. The use of an extensive absorption treatment (not shown) inside the front chamber 368 and the distribution of the acoustic LF energy emitted from an outer edge 392 of the LF driver 304 In this respect, it is important that the floating LF waveguide 316create an acoustic filter for mid-range frequencies that come from the edge 392 The anterior chamber 368 can absorb the midrange frequencies from the edge. Meanwhile, midrange frequencies can be absorbed from a center of the LF driver 304 through the LF waveguide 316 exit.

[0047] The use of multiple exit paths results in the LF energy from these paths being acoustically summed again at the listener's ear. The same 1 / 4 wavelength alignment requirement applies to this energy as described for the crossover energy. Thus, each secondary output has a path length requirement and a frequency dependence that is crucial for this alignment.

[0048] The frequency range just below the effective operation of the LF waveguide 316 can be difficult to maintain in design. These wavelengths can be small enough to be blocked by the obstacles in the anterior chamber368 to be strongly influenced, and may also have difficulty aligning with the LF waveguide energy. Three outputs can be primarily for those frequencies that are just below the effective operation of the LF waveguide 316. You can use the front opening 374 directly above the LF waveguide 316 and the two lateral acoustic outputs 382 on the side surfaces 386 of the loudspeaker ( Fig. 4). The front acoustic output 372 can provide a very direct radiation path for the acoustic LF energy at the upper edges of the radiating surface 320 This output meets the 1 / 4 wavelength requirement for all frequencies generated by the LF driver 304. The acoustic outputs 382 the narrow side can very specifically for a small part of acoustic LF energy from the left and right edge section of the radiating surface 320 be.

[0049] According to one or more embodiments, the loudspeaker 300 a load plate 394 which are located in front of a section of the radiating surface 320 , such as the lower section 396. Accordingly, the load plate 394 adjacent to the proximal end 323 of the LF waveguide 316 In this way, the load plate 394 together with the first RF driver 308a block part of the acoustic LF energy generated by the LF driver 304 radiated. The load plate 394 can fulfill several functions. For example, the load plate 394 a safe storage for the acoustic treatment between the waveguides 316 , 318 and the LF driver 304 which is crucial in suppressing takeover energy that is present in the anterior chamber 368 is enclosed. The load plate 394can also prevent acoustic LF energy from exerting direct pressure on a rear surface 398 the waveguide 316 , 318 The load plate 394 can provide a direct radiation path from the front chamber 368 out and to the rear acoustic outputs 388 by transferring acoustic LF energy from the lower section 396 the radiating surface 320 of the LF driver 304 The design may allow rear chamber slots to enter the front chamber 368 Alternatively, the slots in the rear chamber can radiate directly into the open air.

[0050] According to one or more embodiments, a front chamber is not a requirement, but can be very useful. Edge energy from the radiating surface 320can be broken into separate paths, and it is not granted identical symmetrical paths back to open air. Transfer energy from the edge should be largely absorbed.

[0051] Although exemplary embodiments have been described above, these embodiments are not intended to describe all possible forms of the invention. Rather, the terms used in the description are terms of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Furthermore, the features of various implementing embodiments may be combined to form further embodiments of the invention.

Claims

[1] Loudspeaker, comprising: a loudspeaker cabinet; a low frequency (LF) driver located in the speaker cabinet and a radiating surface configured to radiate acoustic LF energy and a radiating surface opening defined by an outer periphery of the radiating surface; and an LF waveguide defining a first radiation path for LF acoustic energy, the LF waveguide having a proximal opening disposed adjacent the LF driver and extending away from the LF driver to a distal opening to define the first radiation path therethrough, the proximal opening having a proximal opening area smaller than a radiating surface opening area to define a second radiation path for the LF acoustic energy around an outer surface of the LF waveguide. [2] The loudspeaker of claim 1, wherein an inner surface and an outer surface of the LF waveguide have a generally equal acoustic pressure from the LF driver. [3] A loudspeaker according to claim 1, wherein the second radiation path exits the loudspeaker cabinet along a front surface. [4] A loudspeaker according to claim 1, wherein the second radiation path exits the loudspeaker cabinet along at least one of a side surface and a rear surface. [5] The loudspeaker of claim 4, further comprising a load plate immediately in front of a portion of the radiating surface and adjacent the LF waveguide for redirecting the LF acoustic energy along the second radiation path to a rear acoustic output in the rear surface. [6] The loudspeaker of claim 1, wherein a proximal end of the LF waveguide is not physically connected to the LF driver. [7] The loudspeaker of claim 6, wherein the proximal end of the LF waveguide includes a lower edge and a top edge at least partially defining the proximal opening, the lower edge being closer to the radiating surface opening than the top edge. [8] A loudspeaker according to claim 7, wherein the lower edge is closer to a radiation center axis of the LF driver than the upper edge. [9] The loudspeaker of claim 1, further comprising a radio frequency (RF) driver disposed in front of the radiating surface of the LF driver and at least partially blocking the LF acoustic energy radiated from the radiating surface. [10] A loudspeaker according to claim 9, wherein a radiation center axis of the LF driver and a radiation center axis of the HF driver are at an offset angle. [11] A loudspeaker according to claim 9, wherein the RF driver is not coaxial with the LF driver. [12] The loudspeaker of claim 1, further comprising a radio frequency (RF) driver disposed adjacent to the LF driver, wherein a first distance between an acoustic center of the LF driver and an acoustic center of the RF driver is less than one wavelength at a crossover frequency. [13] The loudspeaker of claim 12, wherein the first distance is less than 5 inches (12.7 cm). [14] A loudspeaker according to claim 12, wherein a second distance from the acoustic center of the HF driver to a radiation center axis of the LF driver is smaller than a radius of the radiating surface opening. [15] Loudspeaker, comprising: a loudspeaker cabinet; a low frequency (LF) driver disposed in the loudspeaker enclosure and having a radiating surface configured to radiate LF acoustic energy and having a radiating surface opening defined by an outer periphery of the radiating surface; a radio frequency (RF) driver disposed in front of the radiating surface of the LF driver and at least partially blocking the acoustic LF energy radiated from the radiating surface of the LF driver; and an LF waveguide defining a first radiation path for the LF acoustic energy, the LF waveguide having a proximal opening disposed adjacent the LF driver and extending away from the LF driver to a distal opening to define the first radiation path therethrough, the proximal opening having a proximal opening area smaller than a radiating surface opening area to define a second radiation path for the LF acoustic energy around an outer surface of the LF waveguide, the distal opening of the LF waveguide having a distal opening area larger than the radiating surface opening area; wherein the proximal opening is spaced from the LF driver by a distance to define an air gap between the radiating surface of the LF driver and the proximal opening of the LF waveguide. [16] A loudspeaker according to claim 15, wherein a radiation center axis of the LF driver and a radiation center axis of the HF driver are at an offset angle. [17] A loudspeaker according to claim 15, wherein the second radiation path exits the loudspeaker cabinet along at least one of a side surface and a rear surface. [18] Loudspeaker, comprising: a low frequency (LF) driver having a radiating surface configured to radiate LF acoustic energy and having a radiating surface opening defined by an outer periphery of the radiating surface; and a radio frequency (RF) driver that at least partially blocks the acoustic LF energy radiated by the LF driver; where an acoustic center of the HF driver is offset from a radiation center axis of the LF driver. [19] A loudspeaker according to claim 18, further comprising: an LF waveguide defining a first radiation path for LF acoustic energy, the LF waveguide having a proximal opening disposed adjacent the LF driver and extending away from the LF driver to a distal opening to define the first radiation path therethrough, the proximal opening having a proximal opening area that is smaller than a radiating surface opening area to define a second radiation path for the LF acoustic energy around an outer surface of the LF waveguide, the distal opening of the LF waveguide having a distal opening area that is larger than the proximal opening area. [20] The loudspeaker of claim 19, wherein the LF waveguide is detached from the LF driver to define an air gap between the radiating surface of the LF driver and the proximal opening of the LF waveguide.