Multi-way acoustic wall coupling for surface-mounted loudspeakers

Abstract

Loudspeaker (600), comprising: a loudspeaker housing (606) suitable for surface mounting and having a front (644) with at least one front sound outlet (640) facing a target direction and a rear (658) with at least one rear sound outlet (656) facing a wall surface (602); and a low-frequency (LF) driver (608) arranged in the loudspeaker enclosure (606) and adapted to emit LF sound energy exiting at least from the front sound outlet (640) and the rear sound outlet (656), wherein the LF sound energy exiting from the front sound outlet (640) and radiating in the target direction forms a first LF energy wavefront (870), wherein the LF sound energy exiting from the front sound outlet (640) and reflected from the wall surface (602) forms a second LF energy wavefront (872) trailing the first LF energy wavefront, wherein the LF sound energy,which exits from the rear sound outlet (656) and radiates directly in the target direction, combined with the LF sound energy exiting from the rear sound outlet (656) and reflected from the wall surface (602), forms a third LF energy wavefront (874) that arrives between the first LF energy wavefront (870) and the second LF energy wavefront (872).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 62 / 278,952, filed January 14, 2016, and U.S. Provisional Application Serial No. 62 / 278,959, 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 multi-way baffle coupling for surface-mounted loudspeakers. BACKGROUND

[0003] A sound source radiates energy into its surroundings. If that source is a constructed loudspeaker, its radiated energy has an envelope shaped to present a uniform energy distribution to the audience. A loudspeaker's ability to control its radiated energy in this way is diminished at lower frequencies, where the wavelengths are longer than those of the loudspeaker itself, and the sound energy radiates evenly in all directions. In this case, the loudspeaker is said to be omnidirectional.

[0004] A surface-mounted loudspeaker produces two distinct sound energy inputs, one directly from the transducer and the other reflected from the surface on which it is mounted. The interference of the reflected energy with the direct energy is primarily destructive, producing dramatic frequency response errors. The frequency of these errors is directly related to the time difference between the two energy inputs at the listener. SUMMARY

[0005] One or more embodiments of the present disclosure are directed to a loudspeaker comprising a loudspeaker enclosure and a low-frequency (LF) driver disposed within the loudspeaker enclosure. The loudspeaker enclosure may be adapted for surface mounting and have a front face with at least one front sound output facing a target direction and a rear face with at least one rear sound output facing a wall surface. The low-frequency (LF) driver may be adapted to emit LF sound energy exiting at least the front sound output and the rear sound output. The LF sound energy exiting the front sound output and radiating directly toward the target direction may form a first LF energy wavefront.The low-frequency sound energy exiting the front sound outlet and reflected by the wall surface can form a second low-frequency energy wavefront that delays the first low-frequency energy wavefront. The low-frequency sound energy exiting the rear sound outlet and radiating directly toward the target, combined with the low-frequency sound energy exiting the rear sound outlet and reflected by the wall surface, can form a third low-frequency energy wavefront that arrives between the first low-frequency energy wavefront and the second low-frequency energy wavefront.

[0006] According to one or more embodiments, the first low-frequency energy wavefront may have a magnitude of 0.80. The second low-frequency energy wavefront may have a magnitude of 0.50 and delay the first low-frequency energy wavefront by 3.70 milliseconds. The third low-frequency energy wavefront may have a magnitude of 1.65 and delay the first low-frequency energy wavefront by 1.35 milliseconds.

[0007] The loudspeaker cabinet may further comprise at least one side surface with a lateral sound exit. The LF sound energy exiting the lateral sound exit and radiating in the target direction may form part of the first LF energy wavefront, while the LF sound energy exiting the lateral sound exit and reflecting from the wall surface may form part of the second LF energy wavefront, which delays the first LF energy wavefront. The at least one side surface with a lateral sound exit may comprise two side surfaces, each side surface having the lateral sound exit.

[0008] The loudspeaker enclosure may further include a floor surface with a lower sound outlet. The low-frequency sound energy exiting the lower sound outlet and radiating directly toward the target direction, combined with the low-frequency sound energy exiting the lower sound outlet and reflected from the wall surface, may form part of the third low-frequency energy wavefront arriving between the first low-frequency energy wavefront and the second low-frequency energy wavefront.

[0009] The loudspeaker may further include an LF waveguide coupled to the LF driver and defining a first radiation path for the LF acoustic energy, wherein the at least one front acoustic output includes the LF waveguide. The at least one front acoustic output may include a front opening in the loudspeaker enclosure above the LF waveguide. The LF waveguide may have a proximal opening positioned adjacent the LF driver and extending away from the LF driver to a distal opening to define the first radiation path. The proximal opening may have 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 the LF waveguide and out of the front opening.The loudspeaker may further comprise a load plate directly in front of a bottom portion of the radiating surface and adjacent to the LF waveguide to deflect a portion of the LF sound energy along a third radiation path to the rear sound output.

[0010] One or more additional embodiments of the present disclosure may be directed to a loudspeaker comprising a loudspeaker enclosure, an LF driver, an LF waveguide, and a load plate. The loudspeaker enclosure may include a front surface with a front sound exit, at least one side surface with a side sound exit, a rear surface with at least one rear sound exit, and a bottom surface with a bottom sound exit. The LF driver may be disposed within the loudspeaker enclosure and have a radiating surface adapted to emit LF sound energy and a radiating surface opening defined by an outer perimeter of the radiating surface. The LF waveguide may define a first ray path for the LF sound energy.The LF waveguide may have a proximal aperture positioned adjacent the LF driver and extending away from the LF driver to a distal aperture to define the first radiation path. The proximal aperture may have a proximal aperture area smaller than a radiating surface aperture area to define a second radiation path for the LF acoustic energy around the LF waveguide and out the front acoustic exit and the side acoustic exit. The load plate may be located directly in front of a bottom portion of the radiating surface and adjacent to the LF waveguide to deflect a portion of the LF acoustic energy along a third radiation path to the rear acoustic exit and the bottom acoustic exit.

[0011] A loudspeaker's aiming axis can be approximately 30° downward from the horizontal. Alternatively, a loudspeaker's aiming axis can be between 30° and 60° downward from the horizontal.

[0012] The loudspeaker may further include at least one radio frequency (RF) driver disposed within the loudspeaker enclosure. The at least one RF driver may include a first RF driver coupled to a first RF waveguide and a second RF driver coupled to a second RF waveguide. The LF waveguide, the first RF waveguide, and the second RF waveguide may be formed from a triple waveguide body. The first RF driver may be disposed in front of the radiating surface of the LF driver and at least partially obstruct the LF acoustic energy emitted from the radiating surface.

[0013] One or more additional embodiments of the present disclosure may be directed to a method of radiating sound. The method may include providing a loudspeaker enclosure having a front surface with at least one front sound output facing a target direction and a rear surface with at least one rear sound output facing a wall surface. The method may further include providing a low frequency (LF) driver disposed within the loudspeaker enclosure and adapted to emit LF sound energy exiting at least the front sound output and the rear sound output.The method may also include: generating a first LF energy wavefront from the LF sound energy exiting the front sound exit and radiating directly in the target direction; generating a second LF energy wavefront that delays the first LF energy wavefront from the LF sound energy exiting the front sound exit and reflecting from the wall surface; and generating a third LF energy wavefront that arrives between the first LF energy wavefront and the second LF energy wavefront from the LF sound energy exiting the rear sound exit and radiating directly in the target direction, combined with the LF sound energy exiting the rear sound exit and reflecting from the wall surface.

[0014] According to one or more embodiments, the first low-frequency energy wavefront may have a magnitude of 0.80. The second low-frequency energy wavefront may have a magnitude of 0.50 and delay the first low-frequency energy wavefront by 3.70 milliseconds. The third low-frequency energy wavefront may have a magnitude of 1.65 and delay the first low-frequency energy wavefront by 1.35 milliseconds.

[0015] Providing a loudspeaker enclosure may further comprise providing the loudspeaker enclosure with at least one side surface having a side sound exit. Generating a first LF energy wavefront may comprise generating the first LF energy wavefront from the LF sound energy exiting the front sound exit and the side sound exit and radiating directly in the target direction. Generating a second LF energy wavefront that delays the first LF energy wavefront may comprise generating the second LF energy wavefront from the LF sound energy exiting the front sound exit and the side sound exit and reflecting from the wall surface.

[0016] Furthermore, providing a loudspeaker enclosure may comprise providing the loudspeaker enclosure with at least one side surface having a side sound exit. Furthermore, generating a third LF energy wavefront arriving between the first LF energy wavefront and the second LF energy wavefront may comprise generating the third LF energy wavefront from the LF sound energy exiting the rear sound exit and the lower sound exit and radiating directly toward the target direction, combined with the LF sound energy exiting the rear sound exit and the lower sound exit and reflected from the wall surface. Character list Fig. Figure 1 is a plan view of a surface-mounted loudspeaker in a room environment, showing characteristic behavior in the frequency ranges where the loudspeaker sound radiation pattern is omnidirectional; Fig. Figure 2 is an example graph showing the frequency response resulting from a reflected wave with 3.7 milliseconds of delayed time from a simple single source / single wall coupling loudspeaker configuration; Fig. 3 is a graphical representation showing the frequency response resulting from a design having four sources (and their four corresponding reflections), each with equal low frequency (LF) energy magnitude, according to one or more embodiments of the present disclosure; Fig. 4 is a graph showing the frequency response resulting from a two-source, two-reflection design, according to one or more embodiments of the present disclosure; Fig. 5 is a graph illustrating the frequency response resulting from a two-source, one-reflection design, according to one or more embodiments of the present disclosure; Fig. 6 is a side cross-sectional view of a loudspeaker according to one or more embodiments of the present disclosure; Fig. 7 is an exploded view of the Fig. 6 according to one or more embodiments of the present disclosure; Fig. 8 is an interpretative side view of the low-frequency wavefront input illustrating the characteristic behavior of the loudspeaker in the frequency ranges where the loudspeaker acoustic radiation pattern is omnidirectional, according to one or more embodiments of the present disclosure; Fig. 9 is a simplified, exemplary flow diagram illustrating a method for radiating sound in accordance with one or more embodiments of the present disclosure; and Fig. 10 is an actual 200 Hz radiation balloon of the Fig. 6 and Fig. 7, according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0017] Where appropriate, detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary 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 minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0018] There are numerous situations where speakers must be surface-mounted on a wall. For clarity, surface-mounted speakers do not refer to in-wall speakers, which require cutting into the wall so that the speaker effectively becomes part of the wall. Rather, surface-mounted speakers refer to surface-mounted speakers that are self-contained and use some form of mounting to secure them to the wall (or other) surface. The distance between the speaker's radiation opening and the wall itself becomes a critical dimension. In the frequency ranges where speaker radiation is omnidirectional, the sound interaction of the wall becomes an essential part of the speaker's characteristic behavior.

[0019] Fig. 1 shows the top view of a surface-mounted loudspeaker 100 in a room environment. Fig. Figure 1 shows a typical behavior of a surface-mounted loudspeaker in the frequency ranges where the loudspeaker's sound radiation pattern is omnidirectional. As shown, the loudspeaker is mounted with a mount 104 on a surface 102 , such as a wall. The loudspeaker in this example includes a front face 106 which is 102 away and in the direction of an audience, one of the wall surfaces 102 facing back 108 and two side surfaces 110 . The loudspeaker in this example also includes a radiation opening 112 in the front.

[0020] In general, and at any given moment, half of the omnidirectional energy radiated by the loudspeaker 100 is generally directed towards the audience, while the other half is directed towards the wall surface 102Typical wall constructions form a sound reflector for the sound directed onto the wall surface 102 radiated low-frequency (LF) energy, since most absorbing materials are not effective at low frequencies. The resulting energy contains two wavefronts—a direct (or primary) wavefront 114 and a reflected wavefront 116 . Arrow 118 represents a ray path of the LF sound energy contained in the direct wavefront 114. Arrows 120 represent a radiation path of the LF sound energy, which in the reflected wavefront 116 around a circumference (e.g. the front 106 and the side surfaces 110 ) of the loudspeaker. The direct wavefront 114 and the reflected wavefront 116 are almost equal. However, there is a time delay (t lag ) between the reflected wavefront 116 and the direct wavefront 114(ie the reflected wavefront 116 delays the direct wavefront 114 temporally), as in Fig. 1. The delay is directly related to the speed of the sound propagation time from the radiation opening 112 of the loudspeaker 100 around the perimeter of the speaker to the wall surface 102 and back. The type of reflected wave is a function of the loudspeaker and the acoustic properties of the wall surface 102 .

[0021] For most conventional in-wall speakers, such as those in the professional cinema surround speaker product class, the delay time between the direct wavefront and the reflected wavefront is typically in the range of 1-5 milliseconds. The actual delay time depends on the size of the mount and the size of the speaker. For smaller surface-mounted speakers, the delay time may be less. A delay of 1-5 milliseconds corresponds to a path length delta of 14-68 inches (i.e., the distance between the direct and reflected wavefront). In or around this time range, the resulting sound experience can be negatively affected by canceling out certain frequencies and accentuating others. In the case of canceled frequencies, electronic equalization cannot solve the problem.

[0022] Fig. 2 is an example graphical representation showing the frequency response 200 resulting from a reflected wave with 3.7 milliseconds delayed time of a simple single source / single wall coupling loudspeaker configuration as in Fig. 1. For the purposes of this description, the term "source" refers to any loudspeaker element that radiates sound. A source can be either a sound outlet (i.e., a radiating port) or a separate radiating element (called a driver). Fig. Figure 2 shows the canceled frequencies at 150 Hz and 400 Hz. There is an energy peak at 300 Hz. The primary wavefront, without the reflected energy, would ideally be a flat line at 0 dB in this simulation. Thus, the reflected energy creates both the cancellations and the peaks. For reference, all simulations are intentionally "flattened" above 500 Hz to simplify discussion.

[0023] The reflected energy benefits when the delay times are relatively short compared to the wavelengths involved. When this is the case, the effective power of the loudspeaker is almost doubled, as the audience now receives all the omnidirectional energy. This is evident from the frequency response curve in Figure 2for those frequencies below 60 Hz. One or more embodiments of the present disclosure utilize this property to solve the cancellation problem by dividing the low-frequency sound energy into multiple inputs. Instead of a single source, the loudspeaker design according to the present disclosure may utilize multiple sources at strategic locations on the loudspeaker cabinet. The loudspeaker design of the present disclosure generates a series of wavefronts that are both direct and reflected, with delay times between them strategically chosen to mitigate any detectable cancellations.

[0024] The loudspeaker design used to achieve a series of direct and reflected wavefronts with relatively short delay times sufficient to resolve the frequency cancellations can be implemented in several ways. According to one or more embodiments, the use of redirected energy from a single driver may be used. According to one or more alternative embodiments, multiple drivers may be used. Both designs can achieve similar results, as multi-driver implementations provide the greatest design flexibility.

[0025] The energy arrival delay times and their individual energy magnitudes cannot be arbitrary for good performance. With mathematical similarities to diffusion number theory, only certain combinations balance the response and avoid significant cancellations and spikes. A computer optimization routine can be used to deliver good results. Several simulations created using the optimization routine and an actual product are presented in Fig. 3- Fig. 5. The three simulation solutions presented are based on different design variables and each produce different results. The corresponding magnitudes and delay times for each source or reflection are shown in each frequency response diagram. All simulations are based on the same enclosure size and shape as modeled in the discussion above. In each case, new sources (and their associated wall reflections) are added with optimized magnitudes and delay times to reduce the cancellation notches. Therefore, the primary LF sound energy and its reflection of 3.7 milliseconds are maintained in each solution.

[0026] Fig. 3 is a graphical representation showing the frequency response 300which results from a design with four sources (and their four corresponding reflections, each with the same NF energy magnitude). This solution has the desirable property that there is only a 6 dB difference between coherent summation and incoherent summation, which is the best case. Coherent summation occurs when the wavelengths between summation energies are within ¼ wavelength (in this case, for example, everything below approximately 75 Hz). Incoherent summation occurs when wavelengths of summation energies represent more than ¼ wavelength (in this case, for example, everything above approximately 100 Hz). Implementing a design with four sources and reflections with the required precision can be very difficult, but not impossible. The Fig. 4 and Fig. 5 simulated solutions can be simpler and assume two sources, one primary and one secondary, which are considered practical and effective.

[0027] Fig. 4 shows a second solution that improves the frequency response 400 resulting from a design with two sources and two reflections. The delay times shown are achievable when one source is located at the front of the loudspeaker and the second at the rear. This solution has a difference of 9 dB between coherent and incoherent summation, which could be useful in some designs.

[0028] Fig. 5 shows a third solution that improves the frequency response 500resulting from a design with two sources and one reflection. This solution is achievable with one source on the front of the loudspeaker and one source on the rear of the loudspeaker. In this case, the mounting distance and the location of the rear source are such that the direct energy and its reflection are indistinguishable (e.g., <100 microseconds delay time). The summation of the direct energy and the reflected energy will naturally be a factor 2x if the energies are truly coherent, and in the order of magnitude shown. The overall response is very balanced, and the 7 dB difference between coherent and incoherent summation is very good.

[0029] Fig. 6 and Fig. 7 show details of an example loudspeaker 600 , which is in Fig. 5 simulated solution is used. In particular, Fig. 6 is a side cross-sectional view of the loudspeaker 600, while Fig. 7 an exploded view of the Fig. 6. According to one or more embodiments, the loudspeaker 600 a professional cinema surround speaker. However, other speaker classes can use the various construction techniques described here and achieve similar results. Typically for professional cinema environments, the speaker can be mounted on a wall surface 602 (e.g. a cinema wall) with a bracket 604 surface-mounted, which holds it between 4-8 inches from the wall. The speaker 600 can be a two-way loudspeaker that includes a loudspeaker cabinet 606, an NF driver 608 and at least one high frequency (HF) driver 610 As shown, the at least one RF driver 610 a first RF driver 610a and a second RF driver610b , both adapted to emit low-frequency sound energy. However, the two-way loudspeaker design according to the present disclosure can be used using only a single RF driver.

[0030] The NF driver 608 can be a radiation surface 612 sometimes referred to as a cone or diaphragm, which is adapted to emit low-frequency sound energy. The radiating surface 612 moves like a piston to pump air and generate sound waves in response to electrical audio signals. An outer circumference 614 the radiation area 612 a radiation surface opening 616 define with a radiation surface opening area.

[0031] The NF driver 608 and the two RF drivers 610 may have appropriate waveguides to help direct sound energy. The first RF driver 610acan be physically connected to a first RF waveguide 618a coupled, while the second RF driver 610b physically with a second RF waveguide 618b According to one or more embodiments of the present disclosure, the loudspeaker design may utilize an LF waveguide 620 that is smaller than a conventional low-frequency waveguide. The LF waveguide 620 defines a first beam path 622 for the low-frequency sound energy. The low-frequency waveguide 620 can have a proximal opening 624 which, in addition to the NF driver 608 positioned (coupled to the driver), which can be considerably smaller than the radiating area 612 of the LF driver 608 . The proximal opening 624 of the NF waveguide 620can 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 at least a second radiation path 626 for the LF acoustic energy around an outer surface 628 of the NF waveguide 620 .

[0032] The NF waveguide 620 can be separated from the NF driver 608 to a distal opening 630 (coupling with free air) which defines the first radiation path 622 defined by it. The distal opening 630may define a distal opening area and have a size appropriate for waveguide design practice, as known to one skilled in the art, and to support directivity criteria. For example, the distal opening area may be larger than the proximal opening area. In general, the larger the distal opening 630 , the more control of the directivity.

[0033] The NF waveguide 620 can be used before the NF driver 608 A floating waveguide is not physically connected to its corresponding driver, but is separated from the LF driver. As in Fig. 6, the proximal opening 624 of the NF waveguide 620 from the NF driver 608 be spaced apart by a distance, an air gap 632 between the NF driver 608 and the NF waveguide 620 to define. The air gap 632may exist at least partially, since the proximal opening area of ​​the LF waveguide 620 may be smaller than the radiating surface opening area of ​​the NF driver 608 . Since the radiation area 612 moves in response to electrical audio signals, the distance between the NF driver 608 and the NF waveguide 620—and accordingly the size of the air gap 632—vary.

[0034] By using the NF waveguide 620 a means can be provided to remove the higher frequencies from the radiating surface 612 of the NF driver 608 directly into the NF waveguide 620 (designed to support these frequencies) via the first radiation path 622 without using a compression chamber and without all frequencies in the NF waveguide 620 Accordingly, frequencies that are suitable for the NF waveguide 620are not optimal, another radiation path, such as the second radiation path 626, may be enabled. Multiple paths may be required for good performance. These additional radiation paths may be created using numerous acoustic elements and are primarily designed to address different frequency ranges.

[0035] The three waveguides (the NF waveguide 620 and two RF waveguides 618 ) can consist of a triple waveguide body 634 be formed. The speaker 600 may include two inner chambers - an anterior chamber 636 and a rear chamber 638 The rear chamber 638 can accommodate the NF driver 608 in a ventilated housing. The front chamber 636 can be formed by venting the space directly in front of the LF driver 608and enclosed behind the LF and RF waveguides. According to one or more embodiments, the front chamber 636 up to seven ( 7 ) contain output paths for low-frequency sound energy. A primary sound output can be the low-frequency waveguide 620 itself, which is a critical output for the transition frequencies via the first radiation path 622 Other sound outputs in the loudspeaker 600 may include: a front sound output 640 , which passes through a front opening 642 in a front 644 of the loudspeaker cabinet 606 directly above the NF driver 608 is defined; a lower sound output 646 on a floor surface 648 of the loudspeaker cabinet 606; two side sound outputs 650 through narrow openings 652 in side surfaces 654 of the loudspeaker cabinet 606 are defined (see also Fig. 7); and two rear sound outputs 656 in a back 658 of the loudspeaker cabinet 606 .

[0036] In some embodiments, the LF waveguide 620 the only sound output in the front 644 of the loudspeaker cabinet 606 and can therefore also be referred to as a front sound outlet. In any case, the front sound outlet 640 , which is in the front 644 is arranged, facing a target direction, for example the direction of an audience. The rear sound output 656 in the back 658 of the loudspeaker cabinet 606 can be adapted to the wall surface 602 to be oriented.

[0037] As previously described, the proximal opening 624 of the NF waveguide 620 can be smaller than the radiation surface opening 616 of the NF driver 608. The floating of the LF waveguide 620 can only transfer a part of the LF sound energy from the LF driver 608 via the first radiation path 622 into the NF waveguide 620 Rather, the low-frequency sound energy can be transferred between the low-frequency waveguide 620 via the first radiation path 622 and the other sound outputs discussed above via at least the second radiation path 626 be divided.

[0038] The frequency region immediately below the effective operation of the NF waveguide 620 can be difficult to maintain in the design. These wavelengths can be small enough to be strongly influenced by the obstacles in the anterior chamber 636 to be influenced, and may also have difficulty aligning with the LF waveguide energy. Three sound outputs may be primary for these frequencies, which are just below the effective operation of the LF waveguide. 620You can use the front sound output 640 next to the NF waveguide 620 and the two side sound outputs 650 on the side surfaces 654 of the loudspeaker 600 ( Fig. 7). The front sound output 640 can provide a very direct radiation path for the low-frequency sound energy at the upper edges of the radiation surface 612 This output meets the ¼ wavelength requirement for all frequencies generated by the 608 NF driver. The narrow side sound outputs 650 can be very specific for a small part of the LF sound energy from the left and right edge sections of the radiation surface 612. Thus, the second radiation path 626 further defined by low-frequency sound energy radiating around the outer surface 628 of the NF waveguide 620 radiates and from the front sound output 640 next to the NF waveguide 620exits and / or exits the side sound outlets 650.

[0039] According to one or more embodiments, the loudspeaker 600 a load plate 660 which is arranged in front of a part of the radiating surface 612 is arranged, such as a bottom section 662. Accordingly, the load plate 660 next to the proximal opening 624 of the NF waveguide 620. In this way, the load plate 660 together with the first RF driver 610a block part of the low-frequency sound energy emitted by the low-frequency driver 608 is emitted. The load plate 660 can fulfill several important functions. For example, the load plate 660 a safe landing for sound treatment between the waveguides 618 , 620 and the NF driver 608which is critical for suppressing the transient energy trapped in the front chamber 636. The load plate 660 can also prevent low-frequency sound energy from directly reaching a back 664 of the triple waveguide body 634 under pressure. The load plate 660 can have a third radiation path 666 from the anterior chamber 636 and to the rear sound outputs 656 and / or the lower sound outlet 646 by deflecting the low-frequency sound energy from the floor section 662 the radiation area 612 of the NF driver 608 The design may allow rear chamber vents to radiate into the front chamber 636. Alternatively, the rear chamber vents may radiate directly into the open air. The Fig. 6 and Fig. 7 specifically show the details of the redirection mechanisms (e.g., the load plate 660, the triple waveguide body634 and the front chamber surround) for LF energy used in the loudspeaker construction.

[0040] One or more applications for the loudspeaker product (e.g. professional cinema environments) are such that the sound energy below the loudspeaker 600 may be the most important (towards the audience) and therefore a loudspeaker aiming axis may be approximately 30° downwards from the horizontal. In this orientation, and especially at angles between 30° and 60° downwards, the loudspeaker output delay times are similar to those shown above. Fig. The solution described in section 5.

[0041] Fig. Figure 8 is an interpretative side view of the LF energy wavefront input, which shows the characteristic behavior of the loudspeaker 600in the frequency ranges where the loudspeaker sound radiation pattern is omnidirectional. The LF sound energy emitted from the LF waveguide 620, the front sound output 640 and the side sound outputs 650 exits may be close enough in time (e.g., within 100 microseconds) to act as an arrival, A, forming a first LF energy wavefront 870. Referring again to Fig. 5, the strength of the first LF energy wave front can be approximately 0.80. The corresponding reflections from the wall surface 602 the LF sound energy emitted from the LF waveguide 620 , the front sound output 640 and the side sound outputs 650 can similarly act as a second uniform arrival, B, forming a second LF energy wavefront 872, which the first LF energy wavefront 870 by a first delay time (t 1 ) delayed. As in Fig. 5, the size of the second LF energy wavefront 872 approximately 0.50 and the first delay time t 1 can be approximately 3.70 milliseconds. The low-frequency sound energy emitted from the rear sound outputs 656 and the lower sound output 646 exits, and their corresponding wall surface reflections can be close enough in time to also act as an arrival, C, which generates a third LF energy wavefront 874 which forms the first LF energy wavefront 870 by a second delay time (t 2 ) delayed. The third LF energy wave front 874 can be between the first LF energy wave front 870 and the second LF energy wavefront 872 arrive (ie t 2 < t 1 ). As in Fig. 5, the size of the third LF energy wavefront 874 may be approximately 1.65 and the second delay time t 2can be approximately 1.35 milliseconds. The direct and reflected low-frequency sound energy emitted from the rear sound outputs 656 and the lower sound output 646 due to their proximity to the wall surface 602 as a single arrival. Therefore, three main LF energy wavefront arrivals—two sources (A and C) and one reflection (B)—can be present at these target angles with favorable delay times, mitigating any cancellation notch encountered in conventional surface-mounted loudspeaker designs.

[0042] Fig. 9 is a simplified, exemplary flowchart illustrating a method for radiating sound according to one or more embodiments of the present disclosure. The method may include providing the speaker 600 with the loudspeaker cabinet 606 with a number of sound outputs, as in step 905A primary sound output can be the NF waveguide 620 Other sound outputs in the loudspeaker 600 may include: the front sound outlet 640 in the front 644 of the loudspeaker cabinet 606; the lower sound output 646 on the floor surface 648 of the loudspeaker cabinet 606; two side sound outputs 650 in side surfaces 654 of the loudspeaker cabinet 606; and at least one rear sound output 656 in the back 658 of the loudspeaker cabinet 606 . The front 644 may have at least one front sound output facing the target direction, which carries the NF waveguide 620 may include, and the rear side 658 may have at least one rear sound outlet facing a wall surface 602 is facing.

[0043] The method may further comprise providing the NF driver608 which is located in the speaker cabinet 606 arranged and adapted to emit low-frequency sound energy from the front sound output 640 , the side sound outputs 650 , the rear sound outlet 656 and the lower sound outlet 646 exits as in step 910 provided. According to one or more embodiments, the method may further include providing the LF waveguide 620 connected to the LF driver 608 is coupled as in step 915 As explained above, the NF waveguide 620 may not be physically connected to the NF driver 608 connected so that only a portion of the low-frequency sound energy exits the loudspeaker enclosure via the low-frequency waveguide. The method may also include providing at least one RF driver 610, which is mounted in the loudspeaker enclosure 606arranged to emit RF acoustic energy as in step 920 provided.

[0044] In step 925 Electrical audio signals can be sent to the NF and HF drivers 608 , 610 which causes them to generate low-frequency or high-frequency sound energy. In step 930 the first LF energy wavefront 870 generated from the low-frequency sound energy coming from at least the front sound output 640 and radiates directly in the target direction. The first low-frequency energy wavefront 870 may also include low-frequency sound energy that exits the side sound outlets 650 and radiates directly in the target direction. In step 935 can the second LF energy wavefront 872, which the first LF energy wavefront 870 delayed, from the low-frequency sound energy generated from the front sound output 640and reflected by the wall surface 602. The second LF energy wave front 872 may also contain low-frequency sound energy emitted from the side sound outlets 650 exits and from the wall surface 602 reflected. In step 940 the third LF energy wave front 874 , which is located between the first LF energy wavefront 870 and the second LF energy wavefront 872 arrives, are generated by the low-frequency sound energy coming from the rear sound output 656 and radiates directly into the target direction, combined with the low-frequency sound energy emitted from the rear sound output 656 exits and is reflected from the wall surface 602. The third LF energy wave front 874 may also contain low-frequency sound energy coming from the lower sound outlet 646 and radiates directly into the target direction, combined with the low-frequency sound energy emitted from the lower sound outlet 646exits and from the wall surface 602 reflected.

[0045] Fig. 10 is the actual 200 Hz radiation balloon 1000 of the in Fig. 6 and Fig. 7. Further evidence of the arrangement with two sources within the loudspeaker 600 is the radiation pattern of the Fig. 10. The downward tilt of the pattern is not possible with an omnidirectional source. The radiation pattern is the result of the combination of sources representing two wavefronts that sum at the downward angles. It should be noted that the radiation balloon was measured without any wall interaction, but indicates the presence of two sources.

[0046] Although exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words 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. In addition, the features of various embodiments may be combined to form further embodiments of the invention. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 62 / 278952

[0001] US 62 / 278959

[0001]

Claims

[1] Loudspeaker, comprising: a loudspeaker cabinet suitable for surface mounting and having a front side with at least one front sound output facing a target direction and a rear side with at least one rear sound output facing a wall surface; and a low frequency (LF) driver disposed in the loudspeaker cabinet and adapted to emit LF sound energy exiting at least the front sound output and the rear sound output, wherein the LF sound energy exiting the front sound output and radiating in the target direction forms a first LF energy wavefront, wherein the LF sound energy exiting the front sound output and reflecting from the wall surface forms a second LF energy wavefront that delays the first LF energy wavefront, wherein the LF sound energy exiting the rear sound output and radiating directly in the target direction, combined with the LF sound energy exiting the rear sound output and reflecting from the wall surface, forms a third LF energy wavefront that arrives between the first LF energy wavefront and the second LF energy wavefront. [2] The loudspeaker of claim 1, wherein the first LF energy wavefront has a magnitude of 0.80, the second LF energy wavefront has a magnitude of 0.50 and delays the first LF energy wavefront by 3.70 milliseconds, and the third LF energy wavefront has a magnitude of 1.65 and delays the first LF energy wavefront by 1.35 milliseconds. [3] Loudspeaker according to claim 1, wherein the loudspeaker cabinet further comprises at least one side surface with a lateral sound exit, wherein the LF sound energy emerging from the lateral sound exit and radiating in the target direction forms a part of the first LF energy wavefront, wherein the LF sound energy emerging from the lateral sound exit and reflected by the wall surface forms a part of the second LF energy wavefront, which delays the first LF energy wavefront. [4] The loudspeaker of claim 1, wherein the loudspeaker cabinet further comprises a bottom surface having a lower sound exit, wherein the low-frequency sound energy exiting the lower sound exit and radiating directly in the target direction combined with the low-frequency sound energy exiting the lower sound exit and reflected by the wall surface forms part of the third low-frequency energy wavefront arriving between the first low-frequency energy wavefront and the second low-frequency energy wavefront. [5] The loudspeaker of claim 1, further comprising: an LF waveguide coupled to the LF driver and defining a first radiation path for the LF acoustic energy, wherein the at least one front acoustic output includes the LF waveguide. [6] A loudspeaker according to claim 5, wherein the at least one front sound output includes a front opening in the loudspeaker enclosure above the LF waveguide. [7] The loudspeaker of claim 6, wherein the LF waveguide has a proximal aperture disposed adjacent the LF driver and extending away from the LF driver to a distal aperture to define the first radiation path, the proximal aperture having a proximal aperture area smaller than a radiating surface aperture area to define a second radiation path for the LF acoustic energy around the LF waveguide and out of the front aperture. [8] A loudspeaker according to claim 7, further comprising: a load plate directly in front of a bottom portion of the radiating surface and adjacent to the LF waveguide to deflect a portion of the LF sound energy along a third radiation path to the rear sound exit. [9] Speakers including: a loudspeaker cabinet including a front surface with a front sound output, at least one side surface with a side sound output, a rear surface with at least one rear sound output, and a bottom surface with a bottom sound output; a low frequency (LF) driver disposed within the loudspeaker enclosure and having a radiating surface adapted to emit LF sound energy and a radiating surface opening defined by an outer perimeter of the radiating surface; 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, 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 the LF waveguide and out of the front acoustic exit and the side acoustic exit; and a load plate directly in front of a bottom portion of the radiating surface and adjacent to the LF waveguide to deflect a portion of the LF sound energy along a third radiation path to the rear sound exit and the lower sound exit. [10] A loudspeaker according to claim 9, wherein a target axis of the loudspeaker extends approximately 30° downwards from the horizontal. [11] A loudspeaker according to claim 9, wherein a target axis of the loudspeaker extends between 30° and 60° downwards from the horizontal. [12] The loudspeaker of claim 9, further comprising at least one radio frequency (RF) driver disposed within the loudspeaker enclosure. [13] The loudspeaker of claim 12, wherein the at least one RF driver comprises a first RF driver coupled to a first RF waveguide and a second RF driver coupled to a second RF waveguide. [14] The loudspeaker according to claim 13, wherein the low-frequency waveguide, the first RF waveguide and the second RF waveguide are formed from a triple waveguide body. [15] A method for emitting sound, comprising: Providing a loudspeaker cabinet having a front side with at least one front sound output facing a target direction and a rear side with at least one rear sound output facing a wall surface; Providing a low frequency (LF) driver disposed in the loudspeaker enclosure and adapted to emit LF sound energy exiting at least the front sound output and the rear sound output; Generating a first low-frequency energy wavefront from the low-frequency sound energy exiting the front sound outlet and radiating directly in the target direction; Generating a second LF energy wavefront that delays the first LF energy wavefront from the LF sound energy exiting the front sound outlet and reflected from the wall surface; and Generating a third LF energy wavefront arriving between the first LF energy wavefront and the second LF energy wavefront from the LF sound energy exiting the rear sound exit and radiating directly in the target direction, combined with the LF sound energy exiting the rear sound exit and reflected from the wall surface. [16] The method of claim 15, wherein the first LF energy wavefront has a magnitude of 0.80, the second LF energy wavefront has a magnitude of 0.50 and delays the first LF energy wavefront by 3.70 milliseconds, and the third LF energy wavefront has a magnitude of 1.65 and delays the first LF energy wavefront by 1.35 milliseconds. [17] The method of claim 15, wherein providing a loudspeaker enclosure further comprises providing the loudspeaker enclosure with at least one side surface having a side sound output. [18] The method of claim 17, wherein generating a first LF energy wavefront comprises generating the first LF energy wavefront from the LF acoustic energy exiting the front acoustic output and the side acoustic output and radiating directly in the target direction. [19] The method of claim 17, wherein generating a second LF energy wavefront that delays the first LF energy wavefront comprises generating the second LF energy wavefront from the LF sound energy exiting the front sound exit and the side sound exit and reflected from the wall surface. [20] The method of claim 15, wherein providing a loudspeaker enclosure further comprises providing the loudspeaker enclosure with a bottom surface having a bottom sound exit; and wherein generating a third low-frequency energy wavefront arriving between the first low-frequency energy wavefront and the second low-frequency energy wavefront comprises generating the third low-frequency energy wavefront from the low-frequency sound energy exiting the rear sound exit and the bottom sound exit and radiating directly in the target direction combined with the low-frequency sound energy exiting the rear sound exit and the bottom sound exit and reflecting from the wall surface.