JP3951764B2 - Sound generator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sound generator suitable for use in concerts and the like.
[0002]
[Prior art]
Various speaker systems that meet the user's purpose have been developed. For example, there are directional speaker systems, omnidirectional speaker systems, and systems that place emphasis on bass generation. Here, a directional speaker transmits sound without a drop in output level in a specific direction up to a long distance. In addition, the omnidirectional speaker can be heard with the same sound regardless of where it is in the vicinity of the speaker.
[0003]
[Problems to be solved by the invention]
Here, when listening to the sound of an orchestra, the stringed instrument should be expressed omnidirectionally and the wind instrument should be directional. Even in live performances, stringed instruments have a broad sense of sound, and wind instruments have directivity in the direction of the morning glory axis. Realizing such a sense of reality with a speaker system is difficult because it is necessary to combine the contradictory properties of directivity and omnidirectionality.
For example, consider placing an omnidirectional speaker system and a directional speaker system near the stage. In this case, there is a problem in that blind spots are generated by other speakers and bass sounds too much. Therefore, an object of the present invention is to provide a sound generator that can reduce these problems and generate a non-directional sound and a directional sound in a balanced manner.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is characterized by having the following configuration. The parentheses are examples.
The sound generating device according to claim 1, wherein the sound generating device comprises a polyhedron, and a speaker (woofer speaker, squawker speaker, tweeter speaker) is arranged on at least three sides of the polyhedron, and the speaker is arranged on at least one surface of the polyhedron. A first speaker system (directional speaker system) having directivity and non-directivity formed by arranging speakers on at least two surfaces different from the one surface, and a reproduction sound range thereof is the first speaker. And a second speaker system (an omnidirectional speaker system) which is a reproduction sound range excluding a low sound region portion of the reproduction sound region of the system.
Furthermore, in the configuration according to claim 2, in the sound generator according to claim 1, the speaker mounting surface of the second speaker system is inclined with respect to the speaker mounting surface of the first speaker system. It is characterized by being connected.
Furthermore, in the configuration according to claim 3, in the sound generator according to claim 1 or 2 , the first speaker system has a protrusion, and the second speaker system covers the protrusion. It is provided as follows.
Furthermore, in the configuration according to claim 4, in the sound generator according to claim 1 or 2 , at least one speaker belonging to the first speaker system and at least one speaker belonging to the second speaker system. The speaker is characterized by being attached so as to be deflected in the range of 30 to 120 degrees in the azimuth direction.
Furthermore, in the configuration according to claim 5, in the sound generator according to claim 1 or 2 , the number of speakers in the second speaker system is larger than the number of speakers in the first speaker system. It is characterized by that.
Furthermore, in the configuration according to claim 6, in the sound generator according to any one of claims 1 to 5 , the first and second speaker systems include at least a squawker speaker, The lower limit of the reproduction band of the squawker in the second speaker system is set lower than that of the first speaker system.
In the sound generator according to claim 5, a woofer speaker may be included in the first speaker system.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
1. Configuration of Embodiment A sound generator according to an embodiment of the present invention will be described with reference to FIG.
An acoustic generator according to an embodiment of the present invention includes a directional speaker system, an omnidirectional speaker system, and a frequency filter described later.
In the figure, 100 is a directional speaker system having directivity, 200 is an omnidirectional speaker system, and the omnidirectional speaker system 200 is provided on the directional speaker system 100. In addition, the saran net 250 is covered on the entire surface of the speaker mounting surface.
[0006]
Here, the directional speaker system 100 is formed in an octagonal columnar body, and has a wide side surface on four sides and a narrow side surface between them. In addition, the omnidirectional speaker system 200 is formed in a polygonal frustum shape having a bottom surface that is an octagonal shape that is the same shape as the top surface of the directional speaker system 100 and a side surface shape that is a trapezoid. Furthermore, the directional speaker system 100 has a plurality of vertical surfaces, and a tweeter speaker 101, a squawker speaker 102, and a woofer speaker 103 are attached to one surface thereof.
[0007]
Reference numerals 101 and 201 denote tweeter speakers, which generate high-frequency sounds. Reference numerals 102 and 202 denote squawker speakers, which generate mid-range sounds. Reference numeral 103 denotes a woofer speaker, which generates a low-frequency sound. These speakers include variations such as cone type, horn type, and dome type, and any of them may be applied. In general, there are many large diameters, and the larger the diameter, the lower the reproducible frequency, and a large case (enclosure) is required to make use of the performance of the speaker. Reference numeral 104 denotes a bass reflex hole, which has a function of reversing the phase of the sound emitted from the back surface of the woofer speaker 103 and outputting it to the front surface. Therefore, since the air vibration from the back is cut off and released only from the bass reflex hole, the casing (enclosure) of the directional speaker system 100 is configured to be strong and robust.
[0008]
In the omnidirectional speaker system 200, there are nine speaker mounting surfaces. Two speakers, a squawker speaker 202 and a tweeter speaker 201, are attached to an attachment surface 210 connected to the speaker attachment surface of the directional speaker system 100. On the attachment surfaces 211, 212, and 213 connected to the other wide side surfaces of the directional speaker system 100, two squawker speakers 202 and two tweeter speakers 201 are alternately attached along the peripheral direction of the surface.
[0009]
Therefore, the number of speakers attached to the other speaker attachment surfaces 211, 212, and 213 is larger than the number of speakers attached to the attachment surface 210 among the nine attachment surfaces in the omnidirectional speaker system 200. is more than. Note that the speaker attached to the attachment surfaces 214, 215, 216, 217 connected to the narrow surfaces 114, 115,... Of the directional speaker system 100 is either the squawker speaker 202 or the tweeter speaker 201. It is. Further, on the upper mounting surface 218 of the omnidirectional speaker system 200, the squawker speaker 202 and the tweeter speaker 201 are mounted on the rear portion of the mounting surface 218 one by one.
[0010]
Further, the speaker mounting surface 110 of the directional speaker system 100 and the narrow side surfaces 214, 215, 216, and 217 of the omnidirectional speaker mounting surface are deflected at an angular difference of 45 degrees or 135 degrees in the azimuth direction. It is configured.
[0011]
FIG. 2 is an external view of the housing of the directional speaker system 100. As shown in the drawing, a projecting portion 100 a having a substantially rectangular parallelepiped shape is provided at the center of the upper surface of the directional speaker system 100. A square through hole 100h is provided at the center of the upper surface plate of the directional speaker system 100, and covers the rectangular side plate 100s protruding upward from each side of the through hole 100h and the upper surfaces of the four side plates. The protrusion 100a is constituted by the upper plate 100u. Thereby, the volume inside the directional speaker system 100 is increased by the volume of the protrusion 100a.
[0012]
By the way, an omnidirectional speaker system 200 is provided around the protruding portion so as to cover the protruding portion, and each speaker in the omnidirectional speaker system 200 has a back surface thereof opposed to the protruding portion. Provided. Reference numeral 100b denotes a space for storing an equalizer system, a power amplifier, and the like, which are formed by recesses whose upper and lower, left and right cross-sectional shapes are U-shaped. This is equivalent to increasing the thickness, and serves to prevent sound radiation from the rear surface, and the entire system for generating sound can be accommodated in the housing of the sound generating device, so that convenience in use can be achieved.
[0013]
As shown in FIG. 9, on the speaker mounting surface in the omnidirectional speaker system 200, the speaker is mounted in multiple stages in the vertical direction on the side surface of the trapezoid, and the speaker at a higher position is lower. It has a higher elevation angle than the speaker at the position. Here, the elevation angle means an angle formed by the center line of the speaker and the horizontal plane. In the figure, θ represents the inclination of the tweeter speaker 201, β represents the angle between the tweeter speaker 201 and the speaker mounting surface, and α represents the angle between the squawker speaker 202 and the speaker mounting surface.
[0014]
2. Configuration of Frequency Filter In the sound generator according to the embodiment of the present invention, an input signal is band-divided by a built-in frequency filter, and each divided signal is distributed to each speaker via a power amplifier. A method for connecting the frequency filter will be described with reference to FIG. In the figure, reference numeral 300 denotes a frequency filter, which includes high-pass filters (HPF) 301 and 302, a low-pass filter (LPF) 305, and band-pass filters (BPF) 303 and 304.
Further, a characteristic diagram of the frequency filter 300 is shown in FIG. In the figure, L 41 is the characteristic of the low-pass filter 305, L 42 is the characteristic of the band-pass filter 304, and L 43 is the characteristic of the high-pass filter 301. L44 is a characteristic of the band-pass filter 303, and L45 is a characteristic of the high-pass filter 302. Reference numerals 401 to 405 denote power amplifiers which are configured to amplify independently in each frequency band.
[0015]
A tweeter speaker 101 attached to the directional speaker system 100 is connected to a high-pass filter 301 via a power amplifier 405. When the cutoff frequency of the high-pass filter 301 is designed to be 4 kHz, the measured value is also 4 kHz, and the peak value is −17 dB (L43). The squawker speaker 102 is connected to the band pass filter 304 via the power amplifier 404. The band-pass filter 304 is composed of a high-pass filter with a cutoff frequency of 560 Hz and a low-pass filter with a cutoff frequency of 3.6 kHz. The measured values are also 560 Hz and 3.6 kHz, and the peak value is −9 dB. Yes (L42). The woofer speaker 103 is connected to the low-pass filter 305 via the power amplifier 403. When the cutoff frequency of the low-pass filter 305 is designed to be 450 Hz, the measured value is also 450 Hz, and the peak value is 0 dB (L41).
[0016]
The tweeter speaker 201 attached to the omnidirectional speaker system 200 is connected to the high pass filter 302 via the power amplifier 402. When the cut-off frequency of the high-pass filter 302 is designed to be 3.6 kHz, the measured value is also 3.6 kHz, and the peak value is −13 dB (L45). The squawker speaker 202 is connected to the band pass filter 303 via the power amplifier 401. The band-pass filter 303 is composed of a high-pass filter with a cutoff frequency of 250 Hz and a low-pass filter with a cutoff frequency of 3.6 kHz. The measured values are 250 Hz and 3.6 kHz, and the peak value is − 13 dB (L44).
[0017]
The cut-off frequency 250 Hz of the high-pass filter that constitutes the band-pass filter 303 is lower than the cut-off frequency 560 Hz of the high-pass filter that constitutes the band-pass filter 304. Therefore, the playback area of the squawker speaker 202 attached to the omnidirectional speaker system 200 is secured up to a lower frequency than the squawker speaker 102 attached to the directional speaker system 100.
[0018]
3. The operation signal of the embodiment is input to the frequency filter 300, and a signal having a frequency component suitable for each speaker is distributed.
[0019]
Further, it can be seen that the filter characteristics used for the speakers attached to the omnidirectional speaker system 200 are L44 and L45, and the high-pass filter 302 is used to compensate for the high-pass component of the bandpass filter 303.
[0020]
In the directional speaker system 100, the speaker emits sound toward the front surface of the mounting surface. The frequency filter 300 emits low-frequency sounds by the woofer speaker 103, mid-range sounds by the squawker speaker 102, and high-frequency sounds by the tweeter speaker.
[0021]
On the other hand, the omnidirectional speaker system 200 is formed in a polygonal frustum shape, and a speaker is attached to each surface, so that sound is emitted in an arbitrary direction. Here, since the loudspeaker at a high position has a higher elevation angle than the loudspeaker at a low position, the omnidirectional loudspeaker system 200 is formed in a polygonal pyramid, but the loudspeaker has a hemispherical shape. It has an effect similar to that of being attached.
[0022]
3. Characteristics of the sound generator The characteristics of the sound generator of the present embodiment will be described in comparison with a conventional sound generator. Here, the conventional sound generating device is a substantially rectangular parallelepiped speaker system, in which a woofer speaker, a squawker speaker, and a tweeter speaker are each attached only to the front surface, and a bass reflex hole is provided. Say. The external dimensions are substantially the same as those of the sound generator of the present embodiment.
[0023]
FIG. 5 shows the characteristics of a conventional sound generator, FIG. 6 shows the characteristics of the sound generator of the present embodiment, and FIG. 7 activates only the directional speaker system 100 used in the sound generator of this embodiment. FIG. 8 shows the characteristics when only the omnidirectional speaker system 200 used in the sound generator of the embodiment of the present invention is activated. These figures also show the frequency characteristics of the sound pressure level in the anechoic chamber at a position 1 m away from the sound generator.
[0024]
In these figures, L51, L61, L71, and L81 are characteristics at the front of the speaker, L52, L62, L72, and L82 are characteristics at a position inclined 45 degrees in the azimuth direction from the front of the speaker, and L53, L63, L73, and L83 are Characteristics at a position inclined 90 degrees in the azimuth direction from the front of the speaker, L54, L64, L74, and L84 are characteristics at a position inclined 135 degrees in the azimuth direction from the front of the speaker, and L55, L65, L75, and L85 are the rear faces of the speaker The characteristics are shown. L56, L66, L76, and L86 are obtained by averaging the characteristics on the front surface of the speaker, and L57, L67, L77, and L87 are obtained by averaging the characteristics on the rear surface of the speaker.
[0025]
The vertical axis represents the sound pressure level (SPL: SOUND PRESSURE LEVEL) and is expressed in decibels. The horizontal axis represents frequency [Hz] and is logarithmic. Here, when the effective value of the sound pressure of a certain sound is p [Pa] and the effective value of the reference sound pressure is p ₀ [Pa], the sound pressure level L [dB] is
L = 20 log ₁₀ p / p ₀
Given in. The reference sound pressure p ₀ is 20 [μPa] in the case of sound in the air, and is the minimum audible value for a 1 [kHz] sine wave of a human having almost normal hearing. When p = p ₀ , 0 [dB] is obtained.
[0026]
Referring to the characteristics of the conventional sound generator (FIG. 5), large variations (fine jaggedness) can be seen in the high sound range. This is due to the phase interference of the loudspeaker and appears because the measurement was performed at a position 1 m away from the sound generator. The actual listening distance of this embodiment is assumed to be about 10 m to 20 m. At such a distance, the influence of the phase interference is sufficiently small, so that there is no practical problem. Comparing the characteristic L56 obtained by averaging the values on the front surface of the speaker with the characteristic L57 obtained by averaging the values on the rear surface of the speaker, it can be seen that the difference in the sound pressure level increases as the sound range increases. On the other hand, it can also be seen that in the low sound range, there is almost no difference in sound pressure level between the front surface of the speaker and the rear surface of the speaker.
[0027]
Next, referring to the characteristics (FIG. 7) when only the directional speaker system 100 used in the sound generator of the present embodiment is activated, the characteristics L76 on the front surface of the speaker and the characteristics L77 on the rear surface of the speaker are When comparing the above, it can be seen that the difference in the sound pressure level increases as the sound range increases. On the other hand, in the low sound range, there is no difference in sound pressure level between the front surface of the speaker and the rear surface of the speaker, and there is substantially no directivity.
[0028]
Next, referring to the characteristics (FIG. 8) of only the omnidirectional speaker system 200 used in the sound generation device of the present embodiment, no sound is generated in the low range, but the front of the speaker is in the middle and high range. It can be seen that the characteristics are almost the same on the rear surface of the speaker.
[0029]
Next, referring to the characteristics (FIG. 6) of the sound generator of this embodiment, the difference between the characteristic L66 at the front of the speaker and the characteristic L67 at the rear of the speaker is compared with the difference between the characteristics L56 and L57 of the conventional apparatus. Thus, the level difference is considerably small, and it can be understood that the directivity of the present invention is widened. This is because the omnidirectional speaker system substantially functions in the middle sound range and the high sound range, and the directional speaker system 100 has substantially no directivity in the low sound range. This is because the low frequency of the part is compensated by the directivity part.
[0030]
4). Modifications The present invention is not limited to the above-described embodiments. For example, various modifications are possible as follows, and all are included in the scope of the present invention.
(1) Although the directional speaker system 100 is formed in an octagonal columnar body in the above embodiment, it may be formed in a rectangular parallelepiped or other polygonal columnar body. Further, although the omnidirectional speaker system 200 is formed in an octagonal frustum shape, it is formed in a triangular frustum shape, a quadrangular frustum shape, a hexagonal frustum shape, other polygonal frustum shapes, a polygonal column shape, or a polygonal pyramid shape. Also good.
[0031]
(2) In the present embodiment, the speaker mounting surface of the directional speaker system 100 and the narrow side surface of the omnidirectional speaker mounting surface are configured to be deflected at an angle of 45 degrees or 135 degrees in the azimuth direction. The at least one speaker belonging to the directional speaker system 100 and the at least one speaker belonging to the omnidirectional speaker system 200 are in a range of 30 to 120 degrees in the azimuth direction (120 degrees is the omnidirectional speaker system 200). May be attached so as to be deflected in a regular triangular frustum shape or a regular triangular prism shape.
(3) In the above embodiment, the three-way speaker system and the two-way speaker system are used as the speaker system. However, the speaker system according to the present invention is not limited to this, and there are a plurality of different frequency bands. Any speaker system that combines speakers (for example, a 4-way speaker system) can be used.
[0032]
【The invention's effect】
As described above, according to the present invention, the first speaker system having directivity is provided with the first speaker system having directivity and the second speaker system having non-directivity, and thus the characteristics of the first speaker system having directivity. As a whole, an omnidirectional speaker system is realized.
In the invention according to claim 2, since the volume of the first speaker system is increased by the volume of the protruding portion, the performance of the woofer speaker can be further exhibited.
[Brief description of the drawings]
FIG. 1 is an external view of a sound generator according to an embodiment of the present invention.
FIG. 2 is an external view of a casing of a speaker system having directivity according to a sound generator according to an embodiment of the present invention.
FIG. 3 is a connection diagram of frequency filters.
FIG. 4 is a diagram illustrating characteristics of a frequency filter.
FIG. 5 is a diagram illustrating frequency characteristics of a conventional sound generator.
FIG. 6 is a diagram showing frequency characteristics of the sound generator according to the embodiment of the present invention.
FIG. 7 is a diagram showing frequency characteristics of a speaker system having directivity.
FIG. 8 is a diagram illustrating frequency characteristics of an omnidirectional speaker system.
FIG. 9 is a diagram showing a speaker mounting method in an omnidirectional speaker system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 ... Directional speaker system (first speaker system), 200 ... Non-directional speaker system (second speaker system), 101, 201 ... Tweeter speaker (TWEETER), 102, 202 ... Squawker speaker (SQUAWKER) ), 103 ... Woofer speaker, 104 ... Bass reflex hole, 250 ... Saran net, 300 ... Frequency filter, 301, 302 ... High pass filter (HPF), 303, 304 ... Band pass filter (BPF), 305 ... Low pass filter (LPF), 401, 402, 403, 404, 405 ... power amplifier

Claims (6)

In a sound generator comprising a polyhedron and having speakers arranged on at least three sides thereof,
A first speaker system having directivity formed by arranging speakers on at least one surface of the polyhedron;
A non-directivity comprising speakers arranged on at least two surfaces different from the one surface, and the reproduction sound range is a reproduction sound region excluding a low sound region from the reproduction sound region of the first speaker system ; A sound generator comprising: a speaker system.   2. The sound generator according to claim 1, wherein the speaker mounting surface of the second speaker system is inclined and connected to the speaker mounting surface of the first speaker system. The first speaker system has a protrusion, the second speaker systems sound generating apparatus according to claim 1 or 2, wherein the is provided so as to cover the projecting portion. At least one speaker belonging to the first speaker system and at least one speaker belonging to the second speaker system are mounted so as to be deflected in a range of 30 degrees to 120 degrees in the azimuth direction. The sound generator according to claim 1 or 2 . The sound generator according to claim 1 or 2, wherein the number of speakers in the second speaker system is larger than the number of speakers in the first speaker system. The first and second speaker systems include at least a squawker speaker, and a lower limit of a reproduction band of the squawker in the second speaker system is set lower than that of the squawker of the first speaker system. The sound generator according to any one of claims 1 to 5 .

Images