JP3148484U - Speaker box and speaker system - Google Patents

Abstract

To provide a speaker box and a speaker system capable of remarkably enhancing the output of a low-frequency range of a speaker, particularly a small-diameter speaker. One speaker provided at the center of a front panel is a casing 1 comprising a square front panel 2 and a back panel 4 and four side panels 3 connecting them to form a closed space. A mounting circular hole and four ventilation duct coupling circular holes arranged at equal intervals so as to surround the speaker mounting circular hole are installed. A short tubular ventilation duct 8 is inserted into each of the ventilation duct coupling circular holes, coupled, and a speaker is mounted in the speaker mounting circular hole. [Selection] Figure 2

Description

  The present invention relates to a speaker box and a speaker system in audio equipment, particularly audio equipment for home use, coffee shop / karaoke shop, small studio, and the like.

  There is a strong demand for audio equipment with good sound quality. Of course, the choice of the amplifier is natural, but in general, a small-diameter speaker has a fate that the output is drastically lowered in a low sound region, for example, 100 Hz or less. In order to compensate for this, measures such as using large-diameter speakers or combining large, medium, and small speakers have been taken, but as a result, if low sound is important, the speaker system must be enlarged. In addition, the area occupied by households and small offices will increase, and the price will increase.

  Various ideas have been made for the shape of the speaker box to which the speakers are attached. A box (enclosure) of a type in which speakers and ventilation holes are provided on the front panel of a vertically long casing when viewed from the front and a short tubular ventilation duct is coupled to the ventilation holes is also widely used. In this type, low-frequency sound generated on the back of the speaker diaphragm and confined in the housing is collected by extracting it through the hole or short tubular ventilation duct to enhance the low-frequency output. Is intended. Proposals have been made to arrange four ventilation holes side by side, but no significant improvement in bass output has been observed.

  The present invention provides a speaker box and a speaker system that can remarkably enhance the output of the low frequency range of a speaker, particularly a small-diameter speaker.

  The speaker box according to the present invention is a casing composed of a square front panel and a back panel, and four side panels connected to them to form a closed space, and one speaker provided in the center of the front panel. There are four air duct coupling circular holes arranged at equal intervals so as to surround the speaker mounting circular hole, and each of the vent duct coupling circular holes has a short tubular ventilation. The duct is inserted and connected. The speaker system of the present invention has a speaker mounted in a speaker mounting circular hole in this speaker box. The four side panels refer to four panels: an upper side (planar) panel, a lower side (bottom) panel, a right side panel, and a left side panel.

  Increase the output of the low frequency range of the speaker. This effect is particularly remarkable in a small-diameter speaker.

  The configuration of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 is a front view of a speaker system of the present invention. In the center of the square front panel 2 in the housing 1 (see FIG. 2), one speaker mounting circular hole 5 is provided. The circular hole provided in the center of the front panel is a circular hole drawn around the intersection of two diagonal lines of a square. Four ventilation duct coupling circular holes 7 are arranged at equal intervals so as to surround the mounting circular hole 5. To say that the mounting holes 5 are equally spaced so as to surround the mounting holes 5, as shown in FIG. 1, there are four ventilation duct coupling holes in the circles. The center is located on the diagonal of the square front panel and at a position equidistant from the intersection of the two diagonals of the square.

  FIG. 2 is a side view showing the internal structure of the speaker system. A short tubular ventilation duct 8 is inserted and coupled to each of the ventilation duct coupling circular holes (reference numeral 7 in FIG. 1). A speaker 6 is attached to the speaker attachment circular hole (reference numeral 5 in FIG. 1).

  As shown in the cross-sectional view of FIG. 3, the shape of the ventilation duct 8 is preferably not a so-called “zendo”, but rather slightly opened in a trumpet shape from the back of the housing toward the outlet (near side).

  The knowledge about the size of each part is described. When using a speaker with a diameter of 12 cm, the length of one side of the square front panel is about 30 cm, the depth is about 40 to 50 cm, and for example, 45 cm is appropriate. The length of the short tubular ventilation duct inserted into and coupled to the ventilation duct coupling circular hole 7 is preferably about 20 to 25 cm. The inner diameter is preferably about 4 to 6 cm on the inlet side (inner back side of the casing) and about 8 to 12 cm on the outlet side (front panel side).

As the speaker, a 12 cm corn type full range F-120A manufactured by Fostex was used. The speaker box having the structure shown in FIGS. The specifications are as follows.
Panel material and thickness: Laminated wood, thickness 2.5cm
30cm length on one side of the square front panel,
Internal size of the case: 25 cm long, 25 cm wide, 40 cm deep,
Contents: 20L
Ventilation duct length: 25 cm, inlet side inner diameter: 5 cm, outlet side inner diameter: 8 cm
The frequency characteristics in a low temperature region of 200 Hz or less are shown in FIG.

Comparative example

As for the speaker, a 12 cm cone type full range F-120A manufactured by Fostex is used as the speaker, and the phase reversal type enclosure recommended by the company as the speaker box (width inside the box is 18 cm, height is 29.5 cm, depth is 18 cm, An internal volume of 10 L, a ventilation duct inner diameter of 50 mm, and a depth of 80 mm) was used.
The frequency characteristics in a low temperature region of 200 Hz or less are shown in FIG.

  As can be seen from FIG. 4 and Table 1, a remarkable output improvement is recognized in a low temperature region of 100 Hz or less.

  As is generally well known, it is considered that the speaker unit is attached to an infinite (practically several tens of square meters) baffle plate and the sound is heard. In other words, if you listen to this large plate in a field (where it is not affected by sound interference), the sound coming out of the back will be scattered behind, and the low-phase reverse phase will be heard by the person listening to the sound. Since the minute does not interfere, you can hear the original sound of the speaker. In this case, the vibration pressure of the air released backward is diffused indefinitely, so simply speaking, the speaker cone paper should be able to move back and forth without any air resistance. However, the sound that comes out behind is not used at all. In other words, in this case, only the original sound of the speaker unit can be heard. So, I want to devise some way to extend (amplify) the bass, but it seems that the cone-shaped paper was not fully moved because the conventional sealed enclosure is a sealed space for the speakers. Even if you consider only the bass, if you think that the volume of sound that appears on the front side of the infinite baffle is 1, the sound behind is also considered to be about 1, so if you bring the back sound to the front, That doubles. In other words, the sound pressure level is 6 dB plus. On the other hand, by using a resonant duct with an amplifying action such as a trumpet or a megaphone of an instrument, in this case, from about 20 Hz like a large mountain with a fairly wide band around the lowest resonance frequency of about 65 Hz. An amplification effect could be confirmed in 100 hertz. As a result of the experiment, an amplification effect of about 12 decibels was confirmed at around 65 Hz, so if all the sound behind the baffle was brought forward, it was amplified by about 6 decibels, and this resonance action caused about It was successful in amplifying 6 dB and expanding the low range.

The figure which looked at the front panel in the speaker box of the present invention from the front. The side view which shows the internal structure of a speaker system. Sectional drawing which shows the preferable structure of a ventilation duct. The frequency characteristic figure of the speaker system of this invention. The frequency characteristic figure of a commercially available speaker system. The front view of one Example of the speaker system of this invention. The right view of the speaker system which showed the front view in FIG. The left view of the speaker system which showed the front view in FIG. The upper side (plan) figure of the speaker system which showed the front view in FIG. The lower side (bottom) figure of the speaker system which showed the front view in FIG. The rear view of the speaker system which showed the front view in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing | casing 2 Front panel 3 Side panel 4 Back panel 5 Position of the circular hole for speaker attachment 6 Speaker 7 Position of the circular hole for connecting the ventilation duct 8 Ventilation duct

Claims (2)

  A square front panel and a back panel, and a casing composed of four side panels connected to them to form a closed space, one speaker mounting circular hole provided in the center of the front panel, and the speaker There are four ventilation duct coupling circular holes arranged at equal intervals so as to surround the mounting circular holes, and each of the ventilation duct coupling circular holes is a short opening that opens toward the front panel. Tubular ventilation ducts are inserted and connected, and four ventilation duct coupling holes are located at the center of each circle on the diagonal of the square front panel and equidistant from the intersection of the two diagonals of the square. A speaker box that is installed at a remote location. A square front panel and a back panel, and a casing composed of four side panels connected to them to form a closed space, one speaker mounting circular hole provided in the center of the front panel, and the speaker There are four ventilation duct coupling circular holes arranged at equal intervals so as to surround the mounting circular holes, and each of the ventilation duct coupling circular holes is a short opening that opens toward the front panel. Tubular ventilation ducts are inserted and connected, and speakers are attached to the speaker mounting holes, and four ventilation duct connection holes are formed on the front panel whose center is a square. A speaker system provided on a diagonal line and at a position equidistant from the intersection of two diagonal lines of a square.

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