JP5241139B2 - Speaker system - Google Patents

Description

  The present invention relates to a speaker system provided with a passive radiator.

  In a conventional speaker system, there is a technique in which a passive radiator is provided as a method for increasing and enhancing a sound pressure level in a low sound range (see, for example, Patent Document 1). In this technology, a double voice coil speaker unit is used as a speaker, and a compensation circuit that makes the input impedance constant resistance is inserted into one of the voice coils, thereby reducing the electrical impedance of a certain required band of the system. The sound pressure level is increased.

JP-A-11-146485 (FIGS. 1 and 6)

A conventional speaker system employing a passive radiator is configured as described above, but the vibration amplitude of the passive radiator increases during bass reproduction reinforced by a dual voice coil, so it is not necessary for rolling with a passive radiator. There is a problem that easy vibration is likely to occur. Rolling is an asymmetry of the back pressure applied to the diaphragm (passive radiator) attached to the cabinet, that is, if the whole diaphragm does not move in phase due to pressure imbalance inside the cabinet, and it moves partially in reverse phase, This is a phenomenon that appears as a disturbance of frequency characteristics.
In addition, the conventional speaker system also has a problem in that the bass from the passive radiator is delayed. This is the same even if the above double voice coil speaker unit is adopted.

The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a speaker system that improves rolling of a passive radiator in a low sound range.
Another object of the present invention is to obtain a speaker system that improves the response of a bass from a passive radiator.

In the speaker system according to the present invention, a dual voice coil speaker unit having first and second voice coils to which an input signal is applied and a passive radiator are attached to a cabinet, and the input impedance of the second voice coil is made constant. In a speaker system to which an impedance compensation circuit is connected, the passive radiator is attached to at least one surface of the cabinet and has a plurality of areas with a small area for reducing the pressure imbalance inside the cabinet. A vacant room having a small volume is provided, and a sound emitting hole having an area smaller than the total area of the passive radiator facing the vacant room is provided in the vacant room, and sound from the opposing passive radiator is released from the vacant room. Radiated through sound holes And it is characterized in and.

According to the present invention, an empty room having a volume smaller than that of the cabinet is provided in front of the passive radiator, and a sound emitting hole having an area smaller than the total area of the passive radiator facing the empty room is provided in the empty room. Since it did in this way, there exists an effect that a bass with good responsiveness without a delay is reproduced from a speaker system.

Embodiment 1 FIG.
1A and 1B are explanatory views showing the configuration of a speaker system according to Embodiment 1 of the present invention. FIG. 1A is a sectional view and FIG. 1B is a front view.
In the figure, a double voice coil speaker unit 20 is attached to the cabinet 100 with respect to one opening thereof. The double voice coil speaker unit 20 has a structure in which two first voice coils 21 and second voice coils 22 are attached to a bobbin 23 on the back surface. An audio signal is directly input to the first voice coil 21 from the signal input terminals 11 and 12. On the other hand, an audio signal is given to the second voice coil 22 from the signal input terminals 11 and 12 through an impedance compensation circuit 30 for compensating the electrical impedance of the speaker system. The impedance compensation circuit 30 operates under the same conditions as those described in Patent Document 1.

  The cabinet 100 constitutes a passive radiator type cabinet. Here, the “passive radiator type cabinet” means that a normal speaker unit and a passive radiator are attached, and the passive radiator can resonate in the low frequency range generated in the rear space of the speaker unit to effectively radiate low frequencies to the outside. An acoustically structured cabinet. In the first embodiment, as shown in the figure, the passive radiator 40 is mounted in a predetermined method in a plurality (two in this example) of openings provided on the front plate (one surface) of the cabinet 100. Yes. The two passive radiators 40 are designed to operate with the same characteristics as in the case of one passive radiator.

The reason why a plurality of passive radiators are reduced in area is as follows.
When the low-frequency enhancement is performed by combining the passive radiator type bass reflex system and the double voice coil speaker unit, the amplitude of the passive radiator increases near the anti-resonance frequency. At this time, if the area of the passive radiator is large, the vibration surface displacement is not constant in the sound radiation direction due to the pressure imbalance inside the cabinet, and rolling vibration is likely to occur. For this reason, in the first embodiment, the passive radiator surface is reduced in area so as to reduce the pressure imbalance, and a plurality of the reduced passive radiators are mounted on the cabinet surface to suppress the rolling phenomenon. I am doing so.

  As described above, according to the first embodiment, a plurality of desired passive radiators having an area for reducing the pressure imbalance in the cabinet are attached to at least one surface of the cabinet. As a result, rolling that occurs in the low sound range can be eliminated, and the same characteristics as the desired passive radiator can be achieved.

Embodiment 2. FIG.
2A and 2B are explanatory views showing a configuration of a speaker system according to Embodiment 2 of the present invention. FIG. 2A shows a cross-sectional view and FIG. 2B shows a front view. In the figure, components corresponding to those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted in principle.
In the second embodiment, a small volume vacant chamber 41 is formed inside the cabinet 100 below the double voice coil speaker unit 20, and two passive radiators are provided on the wall 100 inside the cabinet 100 of the vacant chamber 41. 40 is installed. Further, the outer surface of the vacant chamber 41 has a structure having a circular opening that becomes the sound emitting hole 42. The area of the sound emitting hole 42 is set to be smaller than the total area of the two passive radiators 40 as shown in FIG. Therefore, the sound of the passive radiator 40 is radiated so as to be ejected from the sound emitting hole 42 having a small area through the empty chamber 41. Due to this behavior, a bass sound with good response without delay is reproduced from the speaker system.

  2 illustrates an example in which the vacant chamber 41 in which the two passive radiators 40 are mounted is formed inside the cabinet 100 and the sound emission holes 42 are provided on the outer peripheral surface of the cabinet. As described above, the vacant chamber 41 may be formed so as to protrude from the cabinet 100, and the speaker system can perform the same operation as shown in FIG. Further, the vacant chamber 41 may have a structure projecting to both the inside and the outside of the cabinet 100, and the operation and effect are the same.

In FIG. 2, the sound emitting hole 42 is an example of a circular shape, but is not limited thereto, and may be an ellipse, a rectangle, a polygon, and the like, depending on the number of passive radiators. May be combined. The area of the sound emission hole 42 is preferably equal to or less than the area of the passive radiator 40 in order to maintain the effect of ejection. Furthermore, although the position of the sound emitting hole 42 is shown in the example provided in the center of the front surface of the two passive radiators 40, the sound emitting hole 42 may be shifted left and right or up and down while facing the speaker system. Furthermore, the number of the sound emission holes 42 may be divided into a plurality instead of one. For example, as shown in FIG. 4, the vacant chamber 41 may be formed inside the cabinet 100 up to the left and right side surfaces of the cabinet 100, and the elongated rectangular sound emission holes 42 may be provided on the left and right side surfaces of the cabinet 100, respectively. Good.
In addition, although the example using one double voice coil speaker unit 20 was demonstrated in FIG. 2, it is good also as a speaker system carrying a several unit.

  As described above, according to the second embodiment, a vacant room having a volume smaller than that of the cabinet is provided in front of a plurality of passive radiators, and a sound emitting unit having an area smaller than the total area of the passive radiator is provided in the vacant room. Since the holes are provided so that the sound from the passive radiators facing each other is radiated through the vacant chamber and the sound emission holes, the rolling can be eliminated in the same manner as in the first embodiment, and the cabinet is configured with a passive radiator bass reflex. Since this method is used, it is possible to reproduce bass with good response.

Embodiment 3 FIG.
5A and 5B are explanatory views showing the configuration of a speaker system according to Embodiment 3 of the present invention. FIG. 5A shows a cross-sectional view and FIG. 5B shows a front view. In the figure, components corresponding to those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted in principle.
In the first embodiment and the second embodiment, an example in which the present invention is applied to a so-called passive radiator bass reflex system in which a bass region of a sound emitted from the rear portion of the speaker unit 20 is extracted using a passive radiator 40 as the speaker system. I have explained. On the other hand, in the third embodiment, the present invention is applied to a kelton type (also referred to as “band-pass type”) speaker system in which the cabinet 100 includes a passive radiator.

  In FIG. 5, a dual voice coil speaker unit 20 serving as a driver of the passive radiator 40 is disposed behind the passive radiator 40, and a rear space 101 of the speaker unit 20 is sealed. Therefore, the speaker unit 20 emits sound waves to the closed room space 102 having a specific volume, and the passive radiator 40 is driven by a change in atmospheric pressure of the closed room space 102, and sound is emitted to the outside. In this case, the double voice coil speaker unit 20 radiates sound waves up to a high frequency, but since it is isolated behind the passive radiator 40, an unnecessary high frequency component is confined. On the other hand, only a specific low-frequency sound corresponding to the resonance point set by the mass is extracted from the passive radiator 40.

  Therefore, even in a kelton speaker system, a passive phenomenon can cause a rolling phenomenon and a bass delay. Therefore, in the third embodiment, a plurality of passive radiators 40 are reduced in size and attached to the vacant chamber 41. In addition, a sound emitting hole 42 with a small area is provided in the empty room 41.

Embodiment 4 FIG.
6A and 6B are explanatory views showing a configuration of a speaker system according to Embodiment 3 of the present invention. FIG. 6A shows a cross-sectional view and FIG. 6B shows a front view. In the figure, components corresponding to those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted in principle.
In the fourth embodiment, as compared with FIG. 2, there is only one passive radiator 40 that is mounted facing the empty chamber 41. However, when the speaker system is downsized and the passive radiator 40 is also reduced in area, it is not necessary to consider the occurrence of rolling vibration. In such a case, with the structure of the fourth embodiment, it is possible to improve the bass delay of the passive radiator 40 and reproduce the bass with good responsiveness.

It is explanatory drawing which shows the structure of the speaker system by Embodiment 1 of this invention. It is explanatory drawing which shows the structure of the speaker system by Embodiment 2 of this invention. It is explanatory drawing which shows another structure of the speaker system by Embodiment 2 of this invention. It is explanatory drawing which shows another structure of the speaker system by Embodiment 2 of this invention. It is explanatory drawing which shows the structure of the speaker system by Embodiment 3 of this invention. It is explanatory drawing which shows the structure of the speaker system by Embodiment 4 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11, 12 Input terminal, 20 Double voice coil speaker unit, 21 1st voice coil, 22 2nd voice coil, 23 Bobbin, 30 Compensation circuit, 40 Passive radiator, 41 Vacant room, 42 Sound emission hole, 100 Cabinet 101, 102 Cabinet space.

Claims (3)

A speaker in which a dual voice coil speaker unit having first and second voice coils to which an input signal is applied and a passive radiator are attached to a cabinet, and an impedance compensation circuit for making the input impedance constant resistance is connected to the second voice coil. In the system,
The passive radiator is attached to at least one surface of the cabinet
A plurality of areas having an area that reduces the pressure imbalance inside the cabinet,
An empty room having a smaller volume than the cabinet is provided on the front surface of the passive radiator, and the empty room is provided with a sound emitting hole having an area smaller than the total area of the passive radiator facing the empty room, A speaker system, wherein sound from a passive radiator is radiated through the vacant chamber and the sound emitting hole. Double voice coil speaker unit and the passive radiator loudspeaker system according to claim 1, characterized in that attached to the Kelton type cabinet. A speaker in which a dual voice coil speaker unit having first and second voice coils to which an input signal is applied and a passive radiator are attached to a cabinet, and an impedance compensation circuit for making the input impedance constant resistance is connected to the second voice coil. In the system,
An empty room having a smaller volume than the cabinet is provided in front of the passive radiator,
A sound emitting hole having an area smaller than the total area of the passive radiator is provided in the vacant chamber, and sound from the passive radiator is radiated through the vacant chamber and the sound emitting hole. Speaker system.

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