JP2014519293A - Audio speaker device - Google Patents

Abstract

  In the speaker device, the first sound transducer (101) reproduces sound in a low frequency range and has a first axial direction (109). The second sound transducer (103) reproduces sound in the low frequency range and has a second axial direction (111). The third sound transducer (105) reproduces sound in the high frequency range and has a third axial direction (113). The third sound transducer (105) is disposed between the first sound transducer (101) and the second sound transducer (103). Furthermore, the first angle between the first axial direction (109) and the second axial direction (111) is between 20 ° and 120 °, and the first axial direction (109) and the third axial direction The second angle between the axial directions (111) is smaller than the first angle. This device can render sounds with a wide sound stage and provide a good approximation to a point source.

Description

  The present invention relates to a speaker device, and more particularly to a speaker close to point sound source audio reproduction, but is not limited thereto.

  Audio playback from electronic signals is everywhere in today's society. An important operation for generating the rendered sound is the conversion from an electrical signal to an acoustic signal performed by a sound transducer.

  In many audio applications, the ideal sound radiator is an oscillating sphere with no size, full bandwidth, and omnidirectional, also called a point source. However, it is actually impossible to achieve such sound radiation characteristics, and it will prove difficult to try to approach such ideal sound generation because the requests collide with each other. Yes. For example, it is difficult for an ultra-small speaker (i.e., one close to a non-speaker) to move the large amount of air required to reproduce bass frequencies at high sound levels.

  A conventional speaker box includes two or more transducers. These transducers are arranged vertically and receive reproduction in the same frequency range in the region where the frequencies overlap. Therefore, the speaker is very directional and exhibits a strong interference pattern on the vertical plane.

  Patent Document 1 discloses a loudspeaker device that solves some of the drawbacks of conventional speakers and provides point source audio rendering. The speaker device of Patent Document 1 provides a very wide and uniform sound spread, and provides a wide sound stage and a wide sweet spot. However, the sound reproduction provided by this speaker device is not perfect in all scenarios and therefore further improvements are desired.

  Therefore, there is a benefit of improving the speaker device. In particular, a speaker device that is small, low-cost, easy to manufacture, flexible in design, good sound quality, easy to arrange, close to a point sound source, and good performance is preferable.

European Patent No. 097556820

  Accordingly, the present invention preferably alleviates or eliminates one or more of the above disadvantages, alone or in combination.

  In one embodiment of the present invention, a speaker device is provided. The speaker device reproduces sound in a low frequency range, reproduces sound in the low frequency range, a first sound transducer having a first axial direction and a first acoustic center, and a second axial direction. And a second sound transducer having a second center point, and a third sound transducer for reproducing sound in a high frequency range and having a third axial direction and a third center point And a third sound transducer is disposed between the first sound transducer and the second sound transducer, and a first sound transducer between the first axial direction and the second axial direction. The angle is between 20 ° and 120 °, and the second angle between the first axial direction and the third axial direction is smaller than the first angle.

  The present invention may improve the speaker device. Specifically, in many embodiments, sound quality may be improved. This loudspeaker device allows low frequencies to reach the listener through both reflections (such as from the ceiling) and direct paths, improving the focus of the rendered sound and reducing the perceived impact of the rendered sound. Improve. Furthermore, the sensitivity to the characteristics of the viewing environment can be reduced as compared with many speaker devices such as a speaker device using a low-frequency speaker in an upward configuration. At the same time, the present speaker device provides a wide and uniform sound spread as compared with the conventional loudspeaker device, and provides a wide sound stage and a wide sweet spot. In many embodiments, low vertical interference can be achieved.

  In many embodiments, for example, a compact speaker device suitable for mounting a bookshelf type speaker can be realized. In many scenarios, sound quality can be improved. In particular, the point sound source characteristics can be improved. The trade-off between directional sound and omnidirectional sound can be improved, generating a focused sound image and sounding like a point sound source.

  The low frequency range and the high frequency range are divided by the crossover frequency, the low frequency range includes a frequency lower than the crossover frequency, and the high frequency range includes a frequency higher than the crossover frequency.

  When the crossover frequency is measured in an anechoic state, when the sound pressure level is measured at a distance of 1 meter from the second sound transducer, the first and second sound transducers have the same sound as the third sound transducer. This is the frequency at which the pressure level is reached.

  The acoustic center of the sound transducer is specifically the point at which the rendered audio is felt to originate.

  The first sound transducer may be a high efficiency tweeter. The speaker device further includes a drive circuit that supplies a low-frequency drive signal to the first transducer and a high-frequency drive signal to the second transducer from the input audio signal.

  The on-axis direction of the sound transducer is specifically a symmetric radiation axis. For example, the sound transducer is rotationally invariant, i.e. symmetric about the on-axis direction. The axial direction may be the direction of the maximum sound output of the sound transducer. Thus, the axial direction may coincide with the direction in which maximum sound energy is emitted. The axial direction may be defined by an axis passing through the center of the sound transducer.

  The first and second sound transducers can be configured to receive the same drive signal. Specifically, the first and second sound transducers are coupled in a parallel configuration.

  In many embodiments, a compact loudspeaker device can be realized while improving low frequency reproduction. In fact, in many embodiments, the sound transducer is attached to a housing having a volume of less than 40 liters.

  According to an optional feature of the invention, the second angle is not less than 25% of the large one angle.

  This improves performance in many scenarios. In particular, the interference, diffusion and / or directivity of sound radiation is advantageous and the perceived sound stage is improved.

  According to an optional feature of the invention, the second angle is not greater than 75% of the first angle.

  This improves performance in many scenarios. In particular, the interference, diffusion and / or directivity of sound radiation is advantageous and the perceived sound stage is improved.

  In many embodiments, the second angle is advantageously no less than 25% and no more than 75% of the first angle.

  According to an optional feature of the invention, the crossover frequency between the lower frequency range and the higher frequency range determines the speed of sound between the first acoustic center and the second acoustic center. Not higher than the one divided by 2 and multiplied by 2.

  Similarly, in many embodiments, the distance between the first acoustic center and the second acoustic center is not greater than twice the wavelength of the crossover frequency between the low frequency range and the high frequency range.

  This improves performance in many embodiments, and in particular, the first and second sound transducers are perceived as almost a single sound source. Improvement of the interference characteristics of the first and second sound transducers can be realized. In particular, in many scenarios, destructive interference between radiated sound waves can be prevented or reduced.

  According to an optional feature of the invention, the speaker device further comprises drive circuits for driving the first, second and third sound transducers. The drive circuit can provide the delay of the third sound transducer relative to the first sound transducer.

  Thereby, in many embodiments, the performance is improved, and in particular, a speaker device capable of reproducing high-quality sound can be provided, and the approximation to the point sound source sound emission is improved. In particular, this approach provides (almost) temporally coherent sound radiation and the speaker device is perceived as a single point source.

  According to an optional feature of the invention, the delay is the length between the third acoustic center and a midpoint between the first acoustic center and the second acoustic center divided by the speed of sound. No more than twice the nominal delay corresponding to the thing.

  This improves performance in many embodiments, in particular improves temporal coherency and can better approximate point sources.

  According to an optional feature of the invention, the delay is not less than 70% of the nominal delay and not greater than 130% of the nominal delay.

  This improves performance in many embodiments, in particular improves temporal coherency and can better approximate point sources.

  According to an optional feature of the invention, the drive circuit is configured to drive the first sound transducer and the second sound transducer substantially the same.

  This improves performance, in particular, the rendered sound is perceived as high sound quality, widely distributed sound stage, high impact, and not perceived as diffuse. This approach improves the interference characteristics and improves the point source approximation.

  According to an optional feature of the invention, the speaker device further comprises a housing, wherein the housing is attached to the first baffle to which the first sound transducer is attached, and to the second sound transducer. A second baffle that is angled with respect to the first baffle; and a third baffle that provides a transition between the first baffle and the second baffle to which the third sound transducer is attached. Have

  This facilitates implementation and / or improves audio performance.

  According to an optional feature of the invention, the dimension of the third baffle perpendicular to a plane including the third axial direction and the axis between the first acoustic center and the second acoustic center is: Less than the dimension of the first baffle perpendicular to a plane that includes the first axial direction and the axis between the first and second acoustic centers.

  This can improve performance in many embodiments, and in particular, can reduce the effect of reflecting the backward radiation of the third sound transducer and focusing in the forward direction. This attenuates unwanted reflections.

  According to an optional feature of the invention, at least one of the first baffle, the second baffle and the third baffle has a curved profile.

  This can improve performance in many embodiments, and in particular, can reduce the effect of reflecting the backward radiation of the third sound transducer and focusing in the forward direction. This attenuates unwanted reflections.

  According to an optional feature of the invention, the third baffle and the third sound transducer are symmetric with respect to the first sound transducer and the second sound transducer.

  This facilitates implementation and / or improves audio performance.

  According to an optional feature of the invention, the distance between the first acoustic center and the second acoustic center is less than three times the maximum dimension of the first acoustic transducer.

  Thereby, in many embodiments, performance can be improved, and in particular, a speaker device can be provided which provides temporally coherent sound radiation and improves point source radiation approximation. In particular, this feature reduces interference between transducers and improves sound image recognition.

  According to an optional feature of the invention, the minimum distance between the first and second sound transducers is less than three times the maximum dimension of the third sound transducer.

  Thereby, in many embodiments, performance can be improved, and in particular, a speaker device can be provided which provides temporally coherent sound radiation and improves point source radiation approximation. In particular, this feature reduces interference between transducers and improves sound image recognition.

  In one aspect of the present invention, a method for providing a speaker device is provided. The method plays a sound in a low frequency range and provides a first sound transducer having a first axial direction and a first acoustic center; plays the sound in the low frequency range; Providing a second sound transducer having an axial direction and a second center point; playing a sound in a high frequency range; and a third sound having a third axial direction and a third center point Providing a transducer, wherein a third sound transducer is disposed between the first sound transducer and the second sound transducer, the first axial direction and the second axial direction. The first angle between is between 20 ° and 120 °, and the second angle between the first axial direction and the third axial direction is smaller than the first angle.

  These and other aspects, features and advantages of the present invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

An embodiment of the present invention will be described by way of example with reference to the drawings.
It is a figure which shows an example of the speaker apparatus by embodiment of this invention. It is a figure which shows an example of the speaker apparatus by embodiment of this invention. It is a figure which shows an example of the speaker apparatus by embodiment of this invention. It is a figure which shows an example of the speaker apparatus by embodiment of this invention. It is a figure which shows an example of the speaker apparatus by embodiment of this invention. It is a figure which shows an example of the speaker apparatus by embodiment of this invention. It is a figure which shows an example of the speaker apparatus by embodiment of this invention. It is a figure which shows the cross section of an example of the speaker apparatus by embodiment of this invention. It is a figure which shows the cross section of an example of the speaker apparatus by embodiment of this invention. It is a figure which shows the directivity measurement example of a different speaker apparatus. It is a figure which shows the directivity measurement example of a different speaker apparatus. It is a figure which shows the directivity measurement example of a different speaker apparatus. It is a figure which shows the directivity measurement example of a different speaker apparatus.

  1 and 2 show an example of a speaker device according to an embodiment of the present invention. 1 is a sectional view, and FIG. 2 is a full view.

  This speaker device has a first low-frequency (sound) transducer 101. This transducer is a low frequency loudspeaker in this example. The speaker device further includes a second low frequency (sound) transducer 103. This transducer is a low frequency loudspeaker in this example. The speaker device also has a high frequency (sound) transducer 105. This transducer is a high frequency, high efficiency tweeter in this example. In this system, sound transducers 101, 103, and 105 are attached to a housing 107.

  In this example, the first low frequency transducer 101 and the second low frequency transducer 103 are substantially the same transducer. Specifically, they are the same type of transducer and only differ within manufacturing tolerances. However, it will be appreciated that in other embodiments, the first low frequency transducer 101 and the second low frequency transducer 103 may not be the same unit.

  The two low frequency sound transducers 101, 103 are configured to render sound in the same frequency range and are specifically driven by the same drive signal. The high frequency sound transducer 105 is configured to render sound at a higher frequency range than the two low frequency transducers 101, 103. For example, the speaker device includes a crossover filter 301 as shown in FIG. The crossover filter 301 filters the incoming signal so that the lower frequency is sent to the two low frequency sound transducers 101, 103 while the higher frequency is sent to the high frequency sound transducer 105. The crossover filter 301 may be designed as a high pass filter on the path to the high frequency sound transducer 105 and as a low pass filter on the path to the low frequency transducers 101, 103.

  The three sound transducers 101, 103, and 105 are thus two-way speaker devices. The low-frequency transducers 101 and 103 mainly generate sound in the lower frequency range, and the high-frequency transducer 105 is mainly higher. Generates sound in the frequency range. This speaker device has a cross-over frequency. This frequency is defined as the frequency at which the two transducers 101, 103 and the high frequency sound transducer 105 contribute equally to sound generation. In particular, the crossover frequency is a frequency at which the low frequency transducers 101 and 103 and the high frequency transducer 105 generate the same sound pressure level at a distance of 1 meter from the high frequency transducer 101 when measured in an anechoic state. Can be defined.

  Needless to say, crossover and two-way driving can be implemented by explicitly introducing a crossover filter. However, the frequency selective drive by the low frequency sound transducers 101, 103 and the high frequency sound transducer 105 can be determined in whole or in part by the different frequency responses of the sound transducers 101, 103, 105. In fact, in one embodiment, the drive signal is sent directly to all sound transducers 101, 103, 105 in parallel and the crossover frequency is such that the sensitivity of the transducer is the same and the sound pressure level generated is the same. Is determined as a frequency.

  Specifically, the crossover frequency can be determined as the crossover frequency of the signal path from the input to the sound measurement position, for example, one meter before the first low frequency transducer 101. The frequency at which the low frequency sound transducers 101 and 103 provide the same sound pressure level as the high frequency sound transducer 105 for the signal supplied at the input to the drive circuit of the loudspeaker device is determined as the crossover frequency. . In the lower frequency range, including frequencies below the crossover frequency, the low frequency sound transducers 101, 103 provide strong sound pressure and dominate sound rendering. In the higher frequency range, including frequencies higher than the crossover frequency, the low frequency sound transducers 101, 103 provide strong sound pressure and dominate sound rendering.

  Of course, the crossover frequency can be determined to include the characteristics of the active drive circuit 105 of the transducers 101, 103, 105 in some cases. Thus, in some embodiments, the drive circuit may be considered as part of the speaker device, and the influence of the crossover filter may be taken into account when determining the system crossover frequency.

  Thus, in this embodiment, the speaker device has the filter 301 or is driven through the filter 301. The filter 301 receives the audio signal to be reproduced and generates separate drive signals for the two low frequency transducers 101, 103 and the high frequency transducer 105. The crossover filter 301 performs low-pass filtering of the input signal, generates a driving signal for the low-frequency transducers 101 and 103, performs high-pass filtering of the input signal, and generates a driving signal for the high-frequency transducer 105.

  Of course, the following description focuses on an embodiment where the speaker system is a two-way system, but other embodiments may use a three-way or higher system. For example, in another embodiment, the frequency range shared by the low-frequency transducers 101 and 103 in FIG. 1 may be shared by a plurality of speakers such as a mid-range speaker and a subwoofer.

  Each transducer has an axial direction. The on-axis direction of the sound transducer is specifically a symmetric radiation axis. For example, the sound transducer is rotationally invariant, i.e. symmetrical about the axial direction. The axial direction may be the direction of the maximum sound output of the sound transducer. Thus, the axial direction may coincide with the direction in which maximum sound energy is emitted. The axial direction may be defined by an axis passing through the center of the sound transducer.

  In this speaker device, the first low-frequency transducer 101, the second low-frequency transducer 103, and the high-frequency transducer 105 are arranged such that their axial directions are accurate. Further, the high frequency sound transducer 105 is disposed between the first low frequency transducer 101 and the second low frequency transducer 103.

  Specifically, the transducers 101, 103, and 105 are configured so that the angle φW between the axial direction 109 of the first low-frequency transducer 101 and the axial direction 111 of the second low-frequency transducer 103 is 20 ° to 120 °. It is configured to be. Furthermore, the angle φT between the axial direction 109 of the first low frequency transducer 101 and the axial direction 113 of the high frequency sound transducer 105 is an angle between the axial directions of the two low frequency sound transducers 101 and 103. Smaller than.

  The transducer is thus configured to radiate in different directions, and the low frequency sound is directed in two directions that are on either side of the radiation from the high frequency sound transducer 105.

  Furthermore, the three transducers are arranged very close to each other and close to a point source.

  In typical use, the axial direction 109 of the first low frequency transducer 101 corresponds to the horizontal direction and is generally closer to the user's direction. Therefore, the first low frequency transducer 101 provides almost direct sound radiation to the listener. The high frequency sound transducer 105 is generally at a slightly upward angle and provides sound radiation that is not directly directed to the user. However, this device generally has a relatively modest angle of the high frequency sound transducer 105 so that both reflected sound radiation and direct sound radiation occur. The first low frequency transducer 103 is rather arranged upfiring and therefore tends to provide less direct sound radiation, but has increased reflection from the ceiling, walls, etc. .

  In this system, the sound transducer is attached to the housing 107. In this example, the housing 107 forms a closed chamber. The casing 107 may be a closed volume as described above, or may include a bus reflection port, for example. Indeed, the housing may have two or more chambers in some embodiments and may be designed to meet the preferences and requirements of individual embodiments.

  In the example of FIG. 1, the first low-frequency transducer 103 is disposed forward. Thus, when the speaker device is in an operational configuration, for example, when the casing 107 is placed on a substantially horizontal surface such as a floor or a wall, the axial direction 109 of the first low-frequency transducer 101 is the vertical direction. Make an angle of approximately 90 °, ie approximately horizontal.

  The second low frequency transducer 103 is arranged completely or slightly upwards. Thus, when the speaker device is in an operational configuration, for example, when the casing 107 is placed on a substantially horizontal surface such as a floor or a wall, the axial direction of the low-frequency transducer 101 is approximately 20 ° to the horizontal direction. Make an angle of 120 °.

  Furthermore, the high frequency sound transducer 105 is configured between the front firing configuration of the first low frequency transducer 101 and the upfiring configuration of the second low frequency transducer 103. Thus, when the speaker device is in an operational configuration, for example, when the casing 107 is placed on a substantially horizontal surface such as a floor or a wall, the axial direction of the high frequency transducer 105 is approximately 20 ° to the horizontal direction. An angle of 120 ° is formed, but an angle smaller than that of the second low-frequency transducer 103 is formed.

  In this way, the speaker device radiates the low frequency range upward and forward at the same time, and generally reaches the listener through various reflection and indirect paths as well as direct paths. The higher frequency range is radiated from a single sound source, partially towards the viewing position and partially upwards, providing a highly reflective and reverberant sound.

  Thus, the device provides simultaneous sound radiation of low frequency sound to produce both reflected sound radiation and direct sound radiation, with the higher frequency sound radiation in the direction between them. The combined sound radiation interacts closely to provide a sound rendering that feels high quality and has advantageous properties.

  Specifically, the device generally provides a wide sound stage and a wide sweet spot. The device provides a wide and very uniform sound distribution with little interference between the transducers, specifically with little vertical interference. At the same time, the device is less sensitive to changes in the acoustic environment. This loudspeaker device provides very good point sound source approximation and provides sound radiation that is almost temporally coherent.

  In this system, each φW between the axial direction 109 of the first low-frequency transducer 105 and the axial direction 111 of the second low-frequency transducer 105 is in the range of 20 ° to 100 °, in particular 60 ° to 90 °. Particularly advantageous performance is seen when in the range of. Also, particularly advantageous performance is seen when the high frequency sound transducer 105 is at a different angle than the first low frequency transducer 101 and the second low frequency transducer 103. In particular, the angle φT between the axial direction 109 of the first low frequency transducer 101 and the axial direction 113 of the first high frequency sound transducer 105 is equal to the axial direction 109 of the first low frequency transducer 101 and the second low frequency transducer 101. Advantageous performance is seen when in the range of 20% to 75% of the angle φW with respect to the axial direction 111 of the frequency transducer 103, especially when in the range of 40% to 60% of φW.

  These design parameters provide a sound rendering that advantageously trades off between different characteristics and provides particularly advantageous audio perception.

  In many embodiments, the high frequency sound transducer 105 has a symmetrical angle with respect to the first low frequency transducer 101 and the second low frequency transducer 103 to provide a particularly advantageous configuration. Thus, in many embodiments, angle φT is approximately half of angle φW.

  In this example, the loudspeaker has three baffles to which three transducers 101, 103, 105 are attached. Each sound transducer is thus attached to a support structure or surface (baffle). In this example, the casing is box-shaped except that the baffle of the second low frequency transducer 103 and the baffle of the high frequency sound transducer 105 are angled with respect to the baffle of the first low frequency sound transducer 101. It is. The baffle of the high frequency sound transducer 105 is disposed between the baffle of the first low frequency transducer 101 and the baffle of the second low frequency transducer 103. As such, the high frequency sound transducer baffle provides a transition between the baffle of the first low frequency transducer 101 and the baffle of the second low frequency transducer 103. The baffle of the high frequency sound transducer 105 is actually considered to be the side formed by the two baffles of the low frequency transducers 101 and 103. For example, a rounded or smooth transition between the baffles of the low frequency sound transducers 101, 103 can be used as the baffle of the high frequency sound transducer 105. It is preferable to arrange the high frequency sound transducer 105 at the transition portion between the low frequency sound transducers 101 and 103 to reduce directivity.

  Since the high frequency sound transducer baffle is thus between the other baffles, the high frequency sound transducer 105 is between the two low frequency transducers 101, 103. In this example, the three sound transducers 101, 103, and 105 have their center points, specifically their acoustic centers, substantially in line when viewed from the axial point of the first low-frequency sound transducer 101. Aligned so that Furthermore, when the speaker device is in the operating position (ie when used), this line is substantially vertical. However, it will be appreciated that in certain embodiments, one or more transducers may be offset, eg, sideways in the baffle. However, in use, the vertical position of the acoustic center of the high frequency sound transducer 105 is between the vertical position of the first low frequency transducer 101 and the vertical position of the second low frequency transducer 103.

  In this configuration, the distance between the transducers 101, 103, 105 is very close, and indeed in many embodiments the distance between the speakers is as small as possible. Specifically, the distance between the sound centers of the sound transducers is made as small as practical. In fact, in many embodiments, the distance between the acoustic centers of the two low frequency sound transducers 101, 103 is less than three times the maximum dimension of the first acoustic transducer 101 (and / or the second acoustic transducer 103). . In addition, the minimum distance between the first and second sound transducers 101 and 103 is smaller than three times the maximum dimension (generally a diameter) of the third sound transducer 105.

  The speaker device is thus configured such that the acoustic centers of the sound transducers are very close to each other. This can provide a very compact speaker unit, but more importantly, the interaction between the sounds rendered by each sound transducer is improved. Specifically, the rendered sound is close in phase and time aligned.

  The crossover frequency of the speaker device can be selected so that the individual transducers are used in the frequency range that gives the best performance. In this way, the crossover frequency can be selected to improve audio band rendering. In many embodiments, the crossover frequency is advantageously in the interval of 1.5 kHz to 3 kHz.

  However, the crossover frequency is also selected so that the low frequency range rendering from the two sound transducers 101, 103, rather than a single sound transducer, does not cause unacceptable unintentional degradation.

  Specifically, the lower frequency range and the higher frequency range are designed not to be higher than the sound speed divided by the distance between the first acoustic center and the second acoustic center multiplied by 2. . Eventually, the distance between the first acoustic center and the second acoustic center is limited not to be longer than twice the wavelength corresponding to the crossover frequency.

  Thus, the speaker device requires

を満たすように設計される。ここで、ｆｃはクロスオーバ周波数であり、ｃは（例えば、２０°で測定した）音速であり、Ｄは低周波数サウンドトランスデューサ１０１，１０３の音響中心の間の距離である。

Designed to meet. Where fc is the crossover frequency, c is the speed of sound (measured at 20 °, for example), and D is the distance between the acoustic centers of the low frequency sound transducers 101, 103.

  In many embodiments, the speaker device is advantageously more demanding.

を満たす。

Meet.

  By keeping the crossover frequency sufficiently small with respect to the distance between the acoustic centers, the interference between the radiated sounds from the two low frequency sound transducers 101, 103 is kept sufficiently small. Specifically, the sound radiation can be sufficiently coherent in all relevant directions, and the destructive interference between the two sound sources is kept sufficiently small.

  In the above example, the speaker device is a passive speaker device that does not perform amplification. Actually, the sound transducers 101, 103, and 105 are driven through the passive crossover filter 301. However, it goes without saying that in other embodiments, the speaker device may be an active speaker device having active drive circuits for the sound transducers 101, 103, 105. Such driving is provided, for example, by a power amplifier in front of the crossover filter 301 of FIG. In other embodiments, each sound transducer may be individually amplified. An example of this is shown in FIG. For each of the sound transducers 101, 103, and 105, power amplifiers 401, 403, and 405 are provided after the crossover filter. The advantage of such a configuration is that the crossover filter 301 operates at low power, and in fact, various signal processing for each sound transducer 101, 103, 105 can be performed at low power.

  In some embodiments, the signal of the high frequency sound transducer 105 may be delayed compared to the signals of the low frequency sound transducers 101, 103.

  An example of such an embodiment is shown in FIG. This corresponds to the example of FIG. 4 but includes a delay in the signal path of the high frequency sound transducer 105. In this example, the drive signal for the high frequency sound transducer 105 is delayed with respect to the drive signals for the low frequency sound transducers 101 and 103. Delay 501 can be implemented in any suitable manner, for example, an analog or digital delay line.

  In this example, the delay compensates for the difference in distance from the acoustic center of the different sound transducers to the listener. For example, FIG. 6 shows the speaker device of FIG. FIG. 6 shows that each sound transducer 101, 103, 105 has an acoustic center 601, 603, 605. Since the distance between the two low frequency sound transducers 101, 103 is relatively short, the two low frequency sound transducers 101, 103 are acoustic centers between the acoustic centers 601, 603 of the two low frequency sound transducers 101, 103. It appears to emit sound (directly) from a single transducer with 607.

  The acoustic center 605 of the high frequency sound transducer 105 is generally in front of the acoustic center 607 of the combination of the two low frequency sound transducers 101, 103. Therefore, the direct sound wave from the high frequency sound transducer 105 is more advanced than the direct sound waves from the two low frequency sound transducers 101, 103. The system thus delays the signal to the high frequency sound transducer 105 to correct for the time difference between the emitted sound waves. Thus, the delay improves the temporal coherence of the emitted sound and thereby improves the sound quality.

  The actual delay between sound waves depends on the position of the listener, specifically on the angle to the listener (and hence on the height of the listener). However, it can be determined corresponding to the distance between the acoustic center 605 of the high frequency sound transducer 105 and the midpoint 607 of the acoustic centers 601 and 603 of the low frequency sound transducers 101 and 103. The corresponding delay can be determined by Δ = d / c. Here, d is the distance between the acoustic centers, and c is the speed of sound. The nominal delay specifically corresponds to the direct wave delay for the listener along the axial direction 113 of the high frequency sound transducer 105. The delay varies with other locations, but this nominal delay is typically a good approximation.

  Accordingly, the delay of the high frequency sound transducer 105 is generally advantageously less than twice the nominal delay Δ, and is generally advantageously greater than 70% and 130% of the nominal delay Δ. Smaller than.

  This results in the sound rendering feeling sufficiently coherent in time.

  In the example of FIGS. 1 and 2, the speaker device is mounted in a relatively simple housing. However, in some embodiments, a more complex housing shape may be used to improve the quality of rendered audio.

  In some embodiments, the baffle of the high frequency sound transducer 105 may be narrow compared to the baffle of the low frequency sound transducers 101, 103. Specifically, the dimensions of the baffle measured in a direction perpendicular to the plane including the axial direction 113 of the high frequency sound transducer 105 and the axis 609 between the acoustic centers of the low frequency sound transducers 101 and 103 were measured in the same direction ( That is, it may be smaller than the dimensions of the low frequency sound transducer (measured perpendicular to this plane). FIG. 7 shows an example of such an embodiment. This example corresponds to the front view of FIG. 2, with the baffle of the high frequency sound transducer 105 being narrowed. In general, the smaller one is the front of the baffle, which is lowered later. The profile of the baffle is bent, and specifically, is curved away as shown in FIG. FIG. 8 is a top sectional view at the height of the center point of the high frequency sound transducer 105.

  In certain embodiments, one or both of the low frequency sound transducer baffles have a curved profile. For example, as shown in FIG. 9, the cross section has a profile corresponding to a baffle that curves backward from a low frequency.

  The described speaker device provides advantageous sound rendering in many scenarios. Specifically, this approach can better focus the sound towards the listening position.

  For example, compared with the speaker device of Patent Document 1, the speaker device described has improved sound focusing, improved perception of the sound stage, and reduced sensitivity to changes in the acoustic environment.

  For example, FIG. 10 shows horizontal measurement of a single upward low frequency transducer (woofer) in the speaker device of Patent Document 1. The low-pass transducer behaves like an omnidirectional sound source, and a large amount of sound energy is sent behind the speaker box (180 °). This causes undesirable coloration due to reflections from the back wall of the room.

  FIG. 11 shows the directivity measurement of two low frequency transducer devices as described above. As can be seen, in the important frequency interval from 500 Hz to 2 kHz, the energy sent towards the back of the speaker is greatly reduced. For this reason, sound quality is improved.

  FIG. 12 shows an example of measurement of the vertical directionality from the front (0 °) to the back (180 °) of the upward low-frequency transducer (woofer) in the speaker device of Patent Document 1. This device sends strong energy between 700 Hz and 2 kHz to the ceiling (90 °), the maximum energy is in the axial direction of the low frequency transducer (60 ° in this example), and large sound energy is sent after the speaker box. It shows that.

  FIG. 13 shows the corresponding front (0 °) to back (180 °) vertical directivity of the two low frequency transducer configurations as described above. As can be seen, less sound energy is sent to the ceiling and to the rear of the speaker box. The maximum energy is 30 °, the median direction between the axial directions of the two low frequency transducers. In this device, two low-frequency transducers are combined and (when the angle between the low-frequency transducers is 60 °) close to a point source from a listening angle of horizontal +/− 90 ° and vertical +/− 30 °. Provides a directivity pattern.

  The present invention can be implemented in many forms. The components of the embodiments of the invention may be physically, functionally and logically implemented in any suitable way. Functions can also be implemented as a single unit, multiple units, or as part of other functional units.

  Although the invention has been described with reference to embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the present invention is limited only by the accompanying claims. Also, although it may appear that the configuration has been described with respect to specific embodiments, it will be understood by those skilled in the art that various configurations of the described embodiments can be combined according to the present invention. In the claims, the term “comprising” does not exclude the presence of other elements or steps.

  Furthermore, although individually listed, a plurality of means, elements, method steps may be implemented by eg a single unit or processor. In addition, even if individual features are included in different claims, they can be advantageously combined, and even if they are included in different claims, the functions cannot be combined or combined. Nor does it suggest that it is not advantageous. Also, including a configuration in a category of claims does not mean limiting it to that category, but rather indicates that the configuration is equally applicable to other claim categories as needed. . Further, the order of composition in a claim does not indicate a particular order in which the composition must function, and in particular, the order of individual steps in a method claim must be performed in that order. It does not indicate. Rather, the steps may be performed in any suitable order. In addition, the case of handling a single item does not exclude a plurality of cases. Therefore, “one”, “first”, “second” and the like do not exclude a plurality of cases. Reference signs in the claims are provided for clarity and shall not be construed as limiting the scope of the claims.

In one embodiment of the present invention, a speaker device is provided. The speaker device reproduces sound in a low frequency range, reproduces sound in the low frequency range, a first sound transducer having a first axial direction and a first acoustic center, and a second axial direction. And a second sound transducer having a second center point, and a third sound transducer for reproducing sound in a high frequency range and having a third axial direction and a third center point And a third sound transducer is disposed between the first sound transducer and the second sound transducer, and a first sound transducer between the first axial direction and the second axial direction. angle is between 20 ° and 120 °, the second angle between the first axis direction and the third axial is minor than the first angle, the first axis direction and the second Axis direction is front The first sound transducer and the second sound transducer 105 are crossed later .

In one aspect of the present invention, a method for providing a speaker device is provided. The method plays a sound in a low frequency range and provides a first sound transducer having a first axial direction and a first acoustic center; plays the sound in the low frequency range; Providing a second sound transducer having an axial direction and a second center point; playing a sound in a high frequency range; and a third sound having a third axial direction and a third center point Providing a transducer, wherein a third sound transducer is disposed between the first sound transducer and the second sound transducer, the first axial direction and the second axial direction. the first angle between is between 20 ° and 120 °, the second angle between the first axis direction and the third axial is minor than the first angle, said first Axial direction and second axis The direction intersects after the first sound transducer and the second sound transducer 105 .

Claims (15)

A first sound transducer for playing sound in a low frequency range and having a first axial direction and a first center point;
A second sound transducer for reproducing sound in the low frequency range and having a second axial direction and a second center point;
A speaker device having a third sound transducer for reproducing sound in a high frequency range and having a third axial direction and a third center point;
A third sound transducer is disposed between the first sound transducer and the second sound transducer;
The first angle between the first axial direction and the second axial direction is between 20 ° and 120 °;
A second angle between the first axial direction and the third axial direction is smaller than the first angle;
Speaker device.   The speaker device according to claim 1, wherein the second angle is not smaller than 25% of the first angle.   The speaker device according to claim 1, wherein the second angle is not greater than 75% of the first angle.   The crossover frequency between the lower frequency range and the higher frequency range is the speed of sound divided by the distance between the first acoustic center and the second acoustic center multiplied by 2. The speaker device according to claim 1, wherein the speaker device is not higher. A drive circuit for driving the first, second and third sound transducers;
The speaker device according to claim 1, wherein the driving circuit provides a delay of the third sound transducer with respect to the first sound transducer.   The delay is a nominal delay of 2 corresponding to the length between the third acoustic center and the midpoint between the first acoustic center and the second acoustic center divided by the speed of sound. The speaker device according to claim 5, wherein the speaker device is not larger than twice.   The speaker device according to claim 6, wherein the delay is not less than 70% of the nominal delay and not greater than 130% of the nominal delay.   The speaker device according to claim 5, wherein the drive circuit is configured to drive the first sound transducer and the second sound transducer substantially the same. Furthermore, it has a housing | casing, The said housing | casing is
A first baffle to which the first sound transducer is attached;
A second baffle that is angled with respect to the first baffle to which the second sound transducer is attached;
The speaker device of claim 1, comprising a third baffle that provides a transition between the first baffle and the second baffle to which the third sound transducer is attached.   The dimensions of the third baffle perpendicular to the third axial direction and the axis between the first and second acoustic centers are the first axial direction and the first axial direction. The speaker device according to claim 9, wherein the speaker device is smaller than a dimension of the first baffle perpendicular to an axis between an acoustic center and the second acoustic center.   The speaker device according to claim 9, wherein at least one of the first baffle, the second baffle, and the third baffle has a bent profile.   The speaker device according to claim 9, wherein the third baffle and the third sound transducer are symmetrical with respect to the first sound transducer and the second sound transducer.   The speaker device according to claim 1, wherein a distance between the first acoustic center and the second acoustic center is smaller than three times a maximum dimension of the first acoustic transducer.   The speaker device according to claim 1, wherein a minimum distance between the first sound transducer and the second sound transducer is smaller than three times a maximum dimension of the third sound transducer. A method for providing a speaker device, comprising:
Providing a first sound transducer having a first axial direction for reproducing sound in a low frequency range;
Providing a second sound transducer that reproduces sound in a low frequency range and has a second axial direction;
Providing a third sound transducer having a third axial direction and reproducing sound in a high frequency range;
A third sound transducer is disposed between the first sound transducer and the second sound transducer;
The first angle between the first axial direction and the second axial direction is between 20- and 120-;
The method wherein a second angle between the first axial direction and the third axial direction is less than the first angle.

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